From a351433d82d1666d8fb4cd6f57ebaec44a034f72 Mon Sep 17 00:00:00 2001
From: "k.hiro1818" <k.hiro1818@gmail.com>
Date: Sun, 10 May 2026 05:50:43 +0000
Subject: [PATCH 1/6] feat: add NDPC ContestType with classifyContest and name
 label support

Add Next DP Contest (NDPC) support:
- NDPC enum value to Prisma schema
- NDPC constant to ContestType object
- classifyContest recognizes contest_id 'ndpc'
- contestTypePriorities assigns priority 6 (after TDPC)
- getContestNameLabel returns 'NDPC'
- Test cases for all three functions

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
---
 .../add-ndpc-contest-table-provider/plan.md   | 442 ++++++++++++++++++
 prisma/schema.prisma                          |   1 +
 prisma/tasks.ts                               | 140 ++++++
 src/lib/types/contest.ts                      |   1 +
 src/lib/utils/contest.ts                      |  43 +-
 src/test/lib/utils/contest.test.ts            |  24 +
 .../utils/test_cases/contest_name_labels.ts   |   7 +
 src/test/lib/utils/test_cases/contest_type.ts |   7 +
 8 files changed, 648 insertions(+), 17 deletions(-)
 create mode 100644 docs/dev-notes/2026-05-10/add-ndpc-contest-table-provider/plan.md

diff --git a/docs/dev-notes/2026-05-10/add-ndpc-contest-table-provider/plan.md b/docs/dev-notes/2026-05-10/add-ndpc-contest-table-provider/plan.md
new file mode 100644
index 000000000..1e17e810f
--- /dev/null
+++ b/docs/dev-notes/2026-05-10/add-ndpc-contest-table-provider/plan.md
@@ -0,0 +1,442 @@
+# Next DP Contest (NDPC) コンテストテーブル追加 実装計画
+
+**Goal:** コンテストテーブルに Next DP Contest (NDPC) を追加し、EDPC・TDPC・FPS 24 グループに統合する。
+
+**Architecture:** `ContestType.NDPC` を Prisma スキーマ → TypeScript 定数 → `classifyContest` / `contestTypePriorities` / `getContestNameLabel` → `NDPCProvider` → `dps` グループの順に追加する。TDD で各レイヤーを実装する。
+
+**Tech Stack:** Prisma (PostgreSQL enum), TypeScript, Vitest
+
+---
+
+## Context
+
+問題データ (`prisma/tasks.ts` 6349–6488 行) はすでに存在する (`contest_id: 'ndpc'`、問題 A–T の 20 問)。しかし `ContestType.NDPC` が未定義のため、コンテストテーブル上に表示されない。ユーザー指定の仕様：
+
+- 順番: `TDPC` の直後に配置
+- `dps` グループの buttonLabel: `EDPC・TDPC・NDPC・FPS 24`
+
+## 設計の根拠
+
+- `NDPCProvider` は `TDPCProvider` と同じ Pattern 2 (Single Source) — `contest_id === 'ndpc'` による単一フィルター
+- `contestTypePriorities` に NDPC=6 を割り当て、以後のエントリを全て1ずつ上げる (PAST=7, ACL_PRACTICE=8, ..., AOJ_JAG=23)
+  - 理由: 整数優先度の一貫性を保つ。浮動小数点は保守性を損なう。
+- `dp_providers.ts` に同居させることで DP 系プロバイダーをひとつのファイルに集約する (EDPC・TDPC と同じ理由)
+
+## 却下した代替案
+
+- **独立ファイル `ndpc_provider.ts` に分離**: DP 系は `dp_providers.ts` に集約する既存慣習に反する。問題数の違いはプロバイダー実装に影響しない。
+
+---
+
+## 変更ファイル一覧
+
+| ファイル                                                                       | 操作                                                                             |
+| ------------------------------------------------------------------------------ | -------------------------------------------------------------------------------- |
+| `prisma/schema.prisma`                                                         | `ContestType` enum に `NDPC` 追加                                                |
+| `src/lib/types/contest.ts`                                                     | `ContestType` オブジェクトに `NDPC` 追加                                         |
+| `src/lib/utils/contest.ts`                                                     | `classifyContest` / `contestTypePriorities` / `getContestNameLabel` に NDPC 追記 |
+| `src/test/lib/utils/test_cases/contest_type.ts`                                | `ndpc` テストケース追加                                                          |
+| `src/test/lib/utils/test_cases/contest_name_labels.ts`                         | `ndpc` テストケース追加                                                          |
+| `src/test/lib/utils/contest.test.ts`                                           | 3 つの `describe` ブロック追加                                                   |
+| `src/features/tasks/utils/contest-table/dp_providers.ts`                       | `NDPCProvider` クラス追加                                                        |
+| `src/features/tasks/utils/contest-table/dp_providers.test.ts`                  | NDPC をパラメータ化テストに追加                                                  |
+| `src/features/tasks/utils/contest-table/contest_table_provider_groups.ts`      | `dps` プリセット更新                                                             |
+| `src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts` | `dps` テスト更新                                                                 |
+
+---
+
+## Task 1: Prisma スキーマ + マイグレーション
+
+**Files:**
+
+- Modify: `prisma/schema.prisma:307`
+
+- [ ] **Step 1: schema.prisma を編集**
+
+`TDPC // Typical DP Contest` の直後に追加：
+
+```prisma
+NDPC // Next DP Contest
+```
+
+- [ ] **Step 2: マイグレーション実行**
+
+```bash
+pnpm exec prisma migrate dev --name add_ndpc_to_contest_type
+```
+
+Expected: `Your database is now in sync with your schema.` のようなメッセージ。`@prisma/client` が再生成され `ContestTypeOrigin` に `NDPC` が含まれる。
+
+- [ ] **Step 3: 型チェック**
+
+```bash
+pnpm check
+```
+
+Expected: `src/lib/types/contest.ts` で型エラー（`NDPC` がオブジェクトに無い）。これは Task 2 で修正する。
+
+---
+
+## Task 2: TypeScript ContestType 定数更新
+
+**Files:**
+
+- Modify: `src/lib/types/contest.ts:37`
+
+- [ ] **Step 1: NDPC を追加**
+
+```typescript
+NDPC: 'NDPC', // Next DP Contest
+```
+
+`TDPC: 'TDPC', // Typical DP Contest` の直後に挿入。
+
+- [ ] **Step 2: 型チェック**
+
+```bash
+pnpm check
+```
+
+Expected: エラーなし（または NDPC 未使用の警告のみ）。
+
+---
+
+## Task 3: classifyContest / contestTypePriorities / getContestNameLabel 更新 (TDD)
+
+**Files:**
+
+- Modify: `src/test/lib/utils/test_cases/contest_type.ts`
+- Modify: `src/test/lib/utils/test_cases/contest_name_labels.ts`
+- Modify: `src/test/lib/utils/contest.test.ts`
+- Modify: `src/lib/utils/contest.ts`
+
+- [ ] **Step 1: テストケースデータを追加 (contest_type.ts)**
+
+`tdpc` エクスポートの直後に追加：
+
+```typescript
+export const ndpc = [
+  createTestCaseForContestType('NDPC')({
+    contestId: 'ndpc',
+    expected: ContestType.NDPC,
+  }),
+];
+```
+
+- [ ] **Step 2: テストケースデータを追加 (contest_name_labels.ts)**
+
+`tdpc` エクスポートの直後に追加：
+
+```typescript
+export const ndpc = [
+  createTestCaseForContestNameLabel('NDPC')({
+    contestId: 'ndpc',
+    expected: 'NDPC',
+  }),
+];
+```
+
+- [ ] **Step 3: describe ブロックを追加 (contest.test.ts)**
+
+`classifyContest`・`getContestPriority`・`getContestNameLabel` の各 `when contest_id is tdpc` describe の直後に、それぞれ以下を追加：
+
+```typescript
+describe('when contest_id is ndpc', () => {
+  TestCasesForContestType.ndpc.forEach(({ name, value }) => {
+    runTests(`${name}`, [value], ({ contestId, expected }: TestCaseForContestType) => {
+      expect(classifyContest(contestId)).toEqual(expected);
+    });
+  });
+});
+```
+
+```typescript
+describe('when contest_id is ndpc', () => {
+  TestCasesForContestType.ndpc.forEach(({ name, value }) => {
+    runTests(`${name}`, [value], ({ contestId, expected }: TestCaseForContestType) => {
+      expect(getContestPriority(contestId)).toEqual(contestTypePriorities.get(expected));
+    });
+  });
+});
+```
+
+```typescript
+describe('when contest_id is ndpc', () => {
+  TestCasesForContestNameLabel.ndpc.forEach(({ name, value }) => {
+    runTests(`${name}`, [value], ({ contestId, expected }: TestCaseForContestNameLabel) => {
+      expect(getContestNameLabel(contestId)).toEqual(expected);
+    });
+  });
+});
+```
+
+- [ ] **Step 4: テスト失敗を確認**
+
+```bash
+pnpm test:unit src/test/lib/utils/contest.test.ts
+```
+
+Expected: NDPC 関連テストが FAIL。
+
+- [ ] **Step 5: contest.ts を実装**
+
+`classifyContest` — `if (contest_id === 'tdpc')` ブロックの直後に追加：
+
+```typescript
+if (contest_id === 'ndpc') {
+  return ContestType.NDPC;
+}
+```
+
+`contestTypePriorities` — 全体の優先度を調整：
+
+- `[ContestType.NDPC, 6]` を TDPC の直後に追加
+- 以後のエントリを全て 1 ずつ上げる (PAST: 6→7, ACL_PRACTICE: 7→8, ..., AOJ_JAG: 22→23)
+
+新しい優先度マップ:
+
+```typescript
+[ContestType.ABS, 0],
+[ContestType.ABC, 1],
+[ContestType.APG4B, 2],
+[ContestType.TYPICAL90, 3],
+[ContestType.EDPC, 4],
+[ContestType.TDPC, 5],
+[ContestType.NDPC, 6],        // <- 新規
+[ContestType.PAST, 7],        // <- 6→7
+[ContestType.ACL_PRACTICE, 8], // <- 7→8
+[ContestType.JOI, 9],         // <- 8→9
+[ContestType.TESSOKU_BOOK, 10], // <- 9→10
+[ContestType.MATH_AND_ALGORITHM, 11], // <- 10→11
+[ContestType.ARC, 12],        // <- 11→12
+[ContestType.AGC, 13],        // <- 12→13
+[ContestType.ABC_LIKE, 14],   // <- 13→14
+[ContestType.ARC_LIKE, 15],   // <- 14→15
+[ContestType.AGC_LIKE, 16],   // <- 15→16
+[ContestType.AWC, 17],        // <- 16→17
+[ContestType.UNIVERSITY, 18], // <- 17→18
+[ContestType.FPS_24, 19],     // <- 18→19
+[ContestType.OTHERS, 20],     // <- 19→20
+[ContestType.AOJ_COURSES, 21], // <- 20→21
+[ContestType.AOJ_PCK, 22],    // <- 21→22
+[ContestType.AOJ_JAG, 23],    // <- 22→23
+```
+
+`getContestNameLabel` — `if (contestId === 'tdpc') { return 'TDPC'; }` の直後に追加：
+
+```typescript
+if (contestId === 'ndpc') {
+  return 'NDPC';
+}
+```
+
+- [ ] **Step 6: テスト通過を確認**
+
+```bash
+pnpm test:unit src/test/lib/utils/contest.test.ts
+```
+
+Expected: すべて PASS。
+
+- [ ] **Step 7: コミット**
+
+```bash
+git add prisma/schema.prisma prisma/migrations/ src/lib/types/contest.ts src/lib/utils/contest.ts src/test/lib/utils/test_cases/contest_type.ts src/test/lib/utils/test_cases/contest_name_labels.ts src/test/lib/utils/contest.test.ts
+git commit -m "feat: add NDPC ContestType with classifyContest and name label support"
+```
+
+---
+
+## Task 4: NDPCProvider 実装 (TDD)
+
+**Files:**
+
+- Modify: `src/features/tasks/utils/contest-table/dp_providers.test.ts`
+- Modify: `src/features/tasks/utils/contest-table/dp_providers.ts`
+
+- [ ] **Step 1: テストを追加 (dp_providers.test.ts)**
+
+`describe.each` の配列に NDPC エントリを追加：
+
+```typescript
+{
+  providerClass: NDPCProvider,
+  contestType: ContestType.NDPC,
+  contestId: 'ndpc',
+  title: 'Next DP Contest',
+  abbreviationName: 'ndpc',
+  label: 'NDPC provider',
+},
+```
+
+import 行も更新：
+
+```typescript
+import { EDPCProvider, TDPCProvider, NDPCProvider } from './dp_providers';
+```
+
+- [ ] **Step 2: テスト失敗を確認**
+
+```bash
+pnpm test:unit src/features/tasks/utils/contest-table/dp_providers.test.ts
+```
+
+Expected: `NDPCProvider` が未定義で FAIL。
+
+- [ ] **Step 3: NDPCProvider を実装 (dp_providers.ts)**
+
+`TDPCProvider` クラスの直後に追加：
+
+```typescript
+export class NDPCProvider extends ContestTableProviderBase {
+  protected setFilterCondition(): (taskResult: TaskResult) => boolean {
+    return (taskResult: TaskResult) => {
+      if (classifyContest(taskResult.contest_id) !== this.contestType) {
+        return false;
+      }
+
+      return taskResult.contest_id === 'ndpc';
+    };
+  }
+
+  getMetadata(): ContestTableMetaData {
+    return {
+      title: 'Next DP Contest',
+      abbreviationName: 'ndpc',
+    };
+  }
+
+  getDisplayConfig(): ContestTableDisplayConfig {
+    return {
+      isShownHeader: false,
+      isShownRoundLabel: false,
+      roundLabelWidth: '',
+      tableBodyCellsWidth: 'w-1/2 xs:w-1/3 sm:w-1/4 md:w-1/5 lg:w-1/6 2xl:w-1/7 px-1 py-2',
+      isShownTaskIndex: true,
+    };
+  }
+
+  getContestRoundLabel(_contestId: string): string {
+    return '';
+  }
+}
+```
+
+- [ ] **Step 4: テスト通過を確認**
+
+```bash
+pnpm test:unit src/features/tasks/utils/contest-table/dp_providers.test.ts
+```
+
+Expected: すべて PASS。
+
+---
+
+## Task 5: dps グループに NDPCProvider を登録
+
+**Files:**
+
+- Modify: `src/features/tasks/utils/contest-table/contest_table_provider_groups.ts:26,187-195`
+- Modify: `src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts`
+
+- [ ] **Step 1: テストを更新 (contest_table_provider_groups.test.ts)**
+
+`expects to create DPs preset correctly` テストを更新：
+
+```typescript
+test('expects to create DPs preset correctly', () => {
+  const group = prepareContestProviderPresets().dps();
+
+  expect(group.getGroupName()).toBe('EDPC・TDPC・NDPC・FPS 24');
+  expect(group.getMetadata()).toEqual({
+    buttonLabel: 'EDPC・TDPC・NDPC・FPS 24',
+    ariaLabel: 'EDPC, TDPC, NDPC and FPS 24 contests',
+  });
+  expect(group.getSize()).toBe(4);
+  expect(group.getProvider(ContestType.EDPC)).toBeInstanceOf(EDPCProvider);
+  expect(group.getProvider(ContestType.TDPC)).toBeInstanceOf(TDPCProvider);
+  expect(group.getProvider(ContestType.NDPC)).toBeInstanceOf(NDPCProvider);
+  expect(group.getProvider(ContestType.FPS_24)).toBeInstanceOf(FPS24Provider);
+});
+```
+
+import 行に `NDPCProvider` を追加。
+
+- [ ] **Step 2: テスト失敗を確認**
+
+```bash
+pnpm test:unit src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts
+```
+
+Expected: グループ名・サイズ・NDPC provider のアサーションが FAIL。
+
+- [ ] **Step 3: contest_table_provider_groups.ts を更新**
+
+import 行を更新：
+
+```typescript
+import { EDPCProvider, TDPCProvider, NDPCProvider } from './dp_providers';
+```
+
+`dps` プリセットを更新：
+
+```typescript
+dps: () =>
+  new ContestTableProviderGroup(`EDPC・TDPC・NDPC・FPS 24`, {
+    buttonLabel: 'EDPC・TDPC・NDPC・FPS 24',
+    ariaLabel: 'EDPC, TDPC, NDPC and FPS 24 contests',
+  }).addProviders(
+    new EDPCProvider(ContestType.EDPC),
+    new TDPCProvider(ContestType.TDPC),
+    new NDPCProvider(ContestType.NDPC),
+    new FPS24Provider(ContestType.FPS_24),
+  ),
+```
+
+- [ ] **Step 4: テスト通過を確認**
+
+```bash
+pnpm test:unit src/features/tasks/utils/contest-table/
+```
+
+Expected: すべて PASS。
+
+- [ ] **Step 5: 全テストを実行**
+
+```bash
+pnpm test:unit
+```
+
+Expected: すべて PASS。
+
+- [ ] **Step 6: 型チェック**
+
+```bash
+pnpm check
+```
+
+Expected: エラーなし。
+
+- [ ] **Step 7: コミット**
+
+```bash
+git add src/features/tasks/utils/contest-table/dp_providers.ts src/features/tasks/utils/contest-table/dp_providers.test.ts src/features/tasks/utils/contest-table/contest_table_provider_groups.ts src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts
+git commit -m "feat: add NDPCProvider and register in dps contest group"
+```
+
+---
+
+## Verification
+
+```bash
+# 全テスト
+pnpm test:unit
+
+# 型チェック
+pnpm check
+
+# lint
+pnpm lint
+```
+
+期待動作: `pnpm dev` 起動後、コンテストテーブルのフィルターに `EDPC・TDPC・NDPC・FPS 24` ボタンが表示され、NDPC の 20 問 (A–T) が表示される。
diff --git a/prisma/schema.prisma b/prisma/schema.prisma
index 9fcf7c7c5..0f2269f82 100755
--- a/prisma/schema.prisma
+++ b/prisma/schema.prisma
@@ -305,6 +305,7 @@ enum ContestType {
   PAST // Practical Algorithm Skill Test (アルゴリズム実技検定)
   EDPC // Educational DP Contest / DP まとめコンテスト
   TDPC // Typical DP Contest
+  NDPC // Next DP Contest
   JOI // Japanese Olympiad in Informatics
   TYPICAL90 // 競プロ典型 90 問
   TESSOKU_BOOK // 競技プログラミングの鉄則
diff --git a/prisma/tasks.ts b/prisma/tasks.ts
index 8f8de9da5..e2b795a1a 100755
--- a/prisma/tasks.ts
+++ b/prisma/tasks.ts
@@ -6346,6 +6346,146 @@ export const tasks = [
     title: 'A. コンテスト',
     grade: 'Q2',
   },
+  {
+    id: 'ndpc2026_t',
+    contest_id: 'ndpc',
+    problem_index: 'T',
+    name: 'Independent Set',
+    title: 'T. Independent Set',
+  },
+  {
+    id: 'ndpc2026_s',
+    contest_id: 'ndpc',
+    problem_index: 'S',
+    name: 'Two doors',
+    title: 'S. Two doors',
+  },
+  {
+    id: 'ndpc2026_r',
+    contest_id: 'ndpc',
+    problem_index: 'R',
+    name: 'Triples',
+    title: 'R. Triples',
+  },
+  {
+    id: 'ndpc2026_q',
+    contest_id: 'ndpc',
+    problem_index: 'Q',
+    name: 'Union of Intervals',
+    title: 'Q. Union of Intervals',
+  },
+  {
+    id: 'ndpc2026_p',
+    contest_id: 'ndpc',
+    problem_index: 'P',
+    name: 'LIS',
+    title: 'P. LIS',
+  },
+  {
+    id: 'ndpc2026_o',
+    contest_id: 'ndpc',
+    problem_index: 'O',
+    name: 'Game',
+    title: 'O. Game',
+  },
+  {
+    id: 'ndpc2026_n',
+    contest_id: 'ndpc',
+    problem_index: 'N',
+    name: 'Knapsack',
+    title: 'N. Knapsack',
+  },
+  {
+    id: 'ndpc2026_m',
+    contest_id: 'ndpc',
+    problem_index: 'M',
+    name: 'Numeral',
+    title: 'M. Numeral',
+  },
+  {
+    id: 'ndpc2026_l',
+    contest_id: 'ndpc',
+    problem_index: 'L',
+    name: 'LCM',
+    title: 'L. LCM',
+  },
+  {
+    id: 'ndpc2026_k',
+    contest_id: 'ndpc',
+    problem_index: 'K',
+    name: 'Addition and Subtraction',
+    title: 'K. Addition and Subtraction',
+  },
+  {
+    id: 'ndpc2026_j',
+    contest_id: 'ndpc',
+    problem_index: 'J',
+    name: 'Number and Total',
+    title: 'J. Number and Total',
+  },
+  {
+    id: 'ndpc2026_i',
+    contest_id: 'ndpc',
+    problem_index: 'I',
+    name: 'Update Positions',
+    title: 'I. Update Positions',
+  },
+  {
+    id: 'ndpc2026_h',
+    contest_id: 'ndpc',
+    problem_index: 'H',
+    name: 'Coin',
+    title: 'H. Coin',
+  },
+  {
+    id: 'ndpc2026_g',
+    contest_id: 'ndpc',
+    problem_index: 'G',
+    name: 'Mouth',
+    title: 'G. Mouth',
+  },
+  {
+    id: 'ndpc2026_f',
+    contest_id: 'ndpc',
+    problem_index: 'F',
+    name: 'Set',
+    title: 'F. Set',
+  },
+  {
+    id: 'ndpc2026_e',
+    contest_id: 'ndpc',
+    problem_index: 'E',
+    name: 'Summer Vacation',
+    title: 'E. Summer Vacation',
+  },
+  {
+    id: 'ndpc2026_d',
+    contest_id: 'ndpc',
+    problem_index: 'D',
+    name: 'Banknote',
+    title: 'D. Banknote',
+  },
+  {
+    id: 'ndpc2026_c',
+    contest_id: 'ndpc',
+    problem_index: 'C',
+    name: 'String',
+    title: 'C. String',
+  },
+  {
+    id: 'ndpc2026_b',
+    contest_id: 'ndpc',
+    problem_index: 'B',
+    name: 'DAG',
+    title: 'B. DAG',
+  },
+  {
+    id: 'ndpc2026_a',
+    contest_id: 'ndpc',
+    problem_index: 'A',
+    name: 'Polyomino',
+    title: 'A. Polyomino',
+  },
   {
     id: 'math_and_algorithm_bn',
     contest_id: 'math-and-algorithm',
diff --git a/src/lib/types/contest.ts b/src/lib/types/contest.ts
index c44adbaf4..270ead6e2 100644
--- a/src/lib/types/contest.ts
+++ b/src/lib/types/contest.ts
@@ -35,6 +35,7 @@ export const ContestType: { [key in ContestTypeOrigin]: key } = {
   PAST: 'PAST', // Practical Algorithm Skill Test (アルゴリズム実技検定)
   EDPC: 'EDPC', // Educational DP Contest / DP まとめコンテスト
   TDPC: 'TDPC', // Typical DP Contest
+  NDPC: 'NDPC', // Next DP Contest
   JOI: 'JOI', // Japanese Olympiad in Informatics
   TYPICAL90: 'TYPICAL90', // 競プロ典型 90 問
   TESSOKU_BOOK: 'TESSOKU_BOOK', // 競技プログラミングの鉄則
diff --git a/src/lib/utils/contest.ts b/src/lib/utils/contest.ts
index 186ecf30a..eec49444b 100644
--- a/src/lib/utils/contest.ts
+++ b/src/lib/utils/contest.ts
@@ -40,6 +40,10 @@ export const classifyContest = (contest_id: string) => {
     return ContestType.TDPC;
   }
 
+  if (contest_id === 'ndpc') {
+    return ContestType.NDPC;
+  }
+
   if (contest_id.startsWith('past')) {
     return ContestType.PAST;
   }
@@ -270,23 +274,24 @@ export const contestTypePriorities: Map<ContestType, number> = new Map([
   [ContestType.TYPICAL90, 3],
   [ContestType.EDPC, 4],
   [ContestType.TDPC, 5],
-  [ContestType.PAST, 6],
-  [ContestType.ACL_PRACTICE, 7],
-  [ContestType.JOI, 8],
-  [ContestType.TESSOKU_BOOK, 9],
-  [ContestType.MATH_AND_ALGORITHM, 10],
-  [ContestType.ARC, 11],
-  [ContestType.AGC, 12],
-  [ContestType.ABC_LIKE, 13],
-  [ContestType.ARC_LIKE, 14],
-  [ContestType.AGC_LIKE, 15],
-  [ContestType.AWC, 16],
-  [ContestType.UNIVERSITY, 17],
-  [ContestType.FPS_24, 18],
-  [ContestType.OTHERS, 19], // AtCoder (その他)
-  [ContestType.AOJ_COURSES, 20],
-  [ContestType.AOJ_PCK, 21],
-  [ContestType.AOJ_JAG, 22],
+  [ContestType.NDPC, 6],
+  [ContestType.PAST, 7],
+  [ContestType.ACL_PRACTICE, 8],
+  [ContestType.JOI, 9],
+  [ContestType.TESSOKU_BOOK, 10],
+  [ContestType.MATH_AND_ALGORITHM, 11],
+  [ContestType.ARC, 12],
+  [ContestType.AGC, 13],
+  [ContestType.ABC_LIKE, 14],
+  [ContestType.ARC_LIKE, 15],
+  [ContestType.AGC_LIKE, 16],
+  [ContestType.AWC, 17],
+  [ContestType.UNIVERSITY, 18],
+  [ContestType.FPS_24, 19],
+  [ContestType.OTHERS, 20], // AtCoder (その他)
+  [ContestType.AOJ_COURSES, 21],
+  [ContestType.AOJ_PCK, 22],
+  [ContestType.AOJ_JAG, 23],
 ]);
 
 export function getContestPriority(contestId: string): number {
@@ -377,6 +382,10 @@ export const getContestNameLabel = (contestId: string) => {
     return 'TDPC';
   }
 
+  if (contestId === 'ndpc') {
+    return 'NDPC';
+  }
+
   if (contestId.startsWith('past')) {
     return getPastContestLabel(PAST_TRANSLATIONS, contestId);
   }
diff --git a/src/test/lib/utils/contest.test.ts b/src/test/lib/utils/contest.test.ts
index 3267d11aa..d044131cf 100644
--- a/src/test/lib/utils/contest.test.ts
+++ b/src/test/lib/utils/contest.test.ts
@@ -67,6 +67,14 @@ describe('Contest', () => {
         });
       });
 
+      describe('when contest_id is ndpc', () => {
+        TestCasesForContestType.ndpc.forEach(({ name, value }) => {
+          runTests(`${name}`, [value], ({ contestId, expected }: TestCaseForContestType) => {
+            expect(classifyContest(contestId)).toEqual(expected);
+          });
+        });
+      });
+
       describe('when contest_id contains past', () => {
         TestCasesForContestType.past.forEach(({ name, value }) => {
           runTests(`${name}`, [value], ({ contestId, expected }: TestCaseForContestType) => {
@@ -257,6 +265,14 @@ describe('Contest', () => {
         });
       });
 
+      describe('when contest_id is ndpc', () => {
+        TestCasesForContestType.ndpc.forEach(({ name, value }) => {
+          runTests(`${name}`, [value], ({ contestId, expected }: TestCaseForContestType) => {
+            expect(getContestPriority(contestId)).toEqual(contestTypePriorities.get(expected));
+          });
+        });
+      });
+
       describe('when contest_id contains past', () => {
         TestCasesForContestType.past.forEach(({ name, value }) => {
           runTests(`${name}`, [value], ({ contestId, expected }: TestCaseForContestType) => {
@@ -415,6 +431,14 @@ describe('Contest', () => {
         });
       });
 
+      describe('when contest_id is ndpc', () => {
+        TestCasesForContestNameLabel.ndpc.forEach(({ name, value }) => {
+          runTests(`${name}`, [value], ({ contestId, expected }: TestCaseForContestNameLabel) => {
+            expect(getContestNameLabel(contestId)).toEqual(expected);
+          });
+        });
+      });
+
       describe('when contest_id is practice2 (ACL practice)', () => {
         TestCasesForContestNameLabel.aclPractice.forEach(({ name, value }) => {
           runTests(`${name}`, [value], ({ contestId, expected }: TestCaseForContestNameLabel) => {
diff --git a/src/test/lib/utils/test_cases/contest_name_labels.ts b/src/test/lib/utils/test_cases/contest_name_labels.ts
index 30832f6b9..7ce7a8f4a 100644
--- a/src/test/lib/utils/test_cases/contest_name_labels.ts
+++ b/src/test/lib/utils/test_cases/contest_name_labels.ts
@@ -21,6 +21,13 @@ export const tdpc = [
   }),
 ];
 
+export const ndpc = [
+  createTestCaseForContestNameLabel('NDPC')({
+    contestId: 'ndpc',
+    expected: 'NDPC',
+  }),
+];
+
 export const aclPractice = [
   createTestCaseForContestNameLabel('ACL Practice')({
     contestId: 'practice2',
diff --git a/src/test/lib/utils/test_cases/contest_type.ts b/src/test/lib/utils/test_cases/contest_type.ts
index 81b7fdb4d..7e3d10fe9 100644
--- a/src/test/lib/utils/test_cases/contest_type.ts
+++ b/src/test/lib/utils/test_cases/contest_type.ts
@@ -62,6 +62,13 @@ export const tdpc = [
   }),
 ];
 
+export const ndpc = [
+  createTestCaseForContestType('NDPC')({
+    contestId: 'ndpc',
+    expected: ContestType.NDPC,
+  }),
+];
+
 const pastContestData = [
   { name: 'PAST 1st', contestId: 'past201912-open' },
   { name: 'PAST 2nd', contestId: 'past202004-open' },

From a21ccf4759ef7cd15c929cf8dfd6cb8b0c05e0d6 Mon Sep 17 00:00:00 2001
From: "k.hiro1818" <k.hiro1818@gmail.com>
Date: Sun, 10 May 2026 05:58:42 +0000
Subject: [PATCH 2/6] feat: add NDPCProvider and register in dps contest group

Register NDPC in DP contests group:
- NDPCProvider implemented to filter NDPC tasks
- dps preset now includes NDPC alongside EDPC, TDPC, and FPS 24
- Update button label and aria-label to reflect 4 DP contests
- Update affected test cases for priority ordering

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
---
 .../contest_table_provider_groups.test.ts     | 10 +++---
 .../contest_table_provider_groups.ts          | 11 ++++---
 .../utils/contest-table/dp_providers.test.ts  | 10 +++++-
 .../tasks/utils/contest-table/dp_providers.ts | 33 +++++++++++++++++++
 src/test/lib/utils/task.test.ts               | 10 +++---
 5 files changed, 59 insertions(+), 15 deletions(-)

diff --git a/src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts b/src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts
index 979271046..40f5861d6 100644
--- a/src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts
+++ b/src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts
@@ -20,6 +20,7 @@ import {
   ACLProvider,
   EDPCProvider,
   TDPCProvider,
+  NDPCProvider,
   FPS24Provider,
   JOIFirstQualRoundProvider,
   JOISecondQualRound2020OnwardsProvider,
@@ -228,14 +229,15 @@ describe('prepareContestProviderPresets', () => {
   test('expects to create DPs preset correctly', () => {
     const group = prepareContestProviderPresets().dps();
 
-    expect(group.getGroupName()).toBe('EDPC・TDPC・FPS 24');
+    expect(group.getGroupName()).toBe('EDPC・TDPC・NDPC・FPS 24');
     expect(group.getMetadata()).toEqual({
-      buttonLabel: 'EDPC・TDPC・FPS 24',
-      ariaLabel: 'EDPC and TDPC and FPS 24 contests',
+      buttonLabel: 'EDPC・TDPC・NDPC・FPS 24',
+      ariaLabel: 'EDPC, TDPC, NDPC and FPS 24 contests',
     });
-    expect(group.getSize()).toBe(3);
+    expect(group.getSize()).toBe(4);
     expect(group.getProvider(ContestType.EDPC)).toBeInstanceOf(EDPCProvider);
     expect(group.getProvider(ContestType.TDPC)).toBeInstanceOf(TDPCProvider);
+    expect(group.getProvider(ContestType.NDPC)).toBeInstanceOf(NDPCProvider);
     expect(group.getProvider(ContestType.FPS_24)).toBeInstanceOf(FPS24Provider);
   });
 
diff --git a/src/features/tasks/utils/contest-table/contest_table_provider_groups.ts b/src/features/tasks/utils/contest-table/contest_table_provider_groups.ts
index af8aa961d..4504182ca 100644
--- a/src/features/tasks/utils/contest-table/contest_table_provider_groups.ts
+++ b/src/features/tasks/utils/contest-table/contest_table_provider_groups.ts
@@ -23,7 +23,7 @@ import {
   TessokuBookForChallengesProvider,
 } from './tessoku_book_providers';
 import { MathAndAlgorithmProvider } from './math_and_algorithm_provider';
-import { EDPCProvider, TDPCProvider } from './dp_providers';
+import { EDPCProvider, TDPCProvider, NDPCProvider } from './dp_providers';
 import { FPS24Provider } from './fps24_provider';
 import { ACLPracticeProvider, ACLBeginnerProvider, ACLProvider } from './acl_providers';
 import {
@@ -182,15 +182,16 @@ export const prepareContestProviderPresets = () => {
       }).addProvider(new MathAndAlgorithmProvider(ContestType.MATH_AND_ALGORITHM)),
 
     /**
-     * DP group (EDPC and TDPC)
+     * DP group (EDPC, TDPC, NDPC, and FPS 24)
      */
     dps: () =>
-      new ContestTableProviderGroup(`EDPC・TDPC・FPS 24`, {
-        buttonLabel: 'EDPC・TDPC・FPS 24',
-        ariaLabel: 'EDPC and TDPC and FPS 24 contests',
+      new ContestTableProviderGroup(`EDPC・TDPC・NDPC・FPS 24`, {
+        buttonLabel: 'EDPC・TDPC・NDPC・FPS 24',
+        ariaLabel: 'EDPC, TDPC, NDPC and FPS 24 contests',
       }).addProviders(
         new EDPCProvider(ContestType.EDPC),
         new TDPCProvider(ContestType.TDPC),
+        new NDPCProvider(ContestType.NDPC),
         new FPS24Provider(ContestType.FPS_24),
       ),
 
diff --git a/src/features/tasks/utils/contest-table/dp_providers.test.ts b/src/features/tasks/utils/contest-table/dp_providers.test.ts
index 68556daaa..92cc9407c 100644
--- a/src/features/tasks/utils/contest-table/dp_providers.test.ts
+++ b/src/features/tasks/utils/contest-table/dp_providers.test.ts
@@ -3,7 +3,7 @@ import { describe, test, expect } from 'vitest';
 import { ContestType } from '$lib/types/contest';
 import type { TaskResults } from '$lib/types/task';
 
-import { EDPCProvider, TDPCProvider } from './dp_providers';
+import { EDPCProvider, TDPCProvider, NDPCProvider } from './dp_providers';
 
 describe('DP providers', () => {
   describe.each([
@@ -23,6 +23,14 @@ describe('DP providers', () => {
       abbreviationName: 'tdpc',
       label: 'TDPC provider',
     },
+    {
+      providerClass: NDPCProvider,
+      contestType: ContestType.NDPC,
+      contestId: 'ndpc',
+      title: 'Next DP Contest',
+      abbreviationName: 'ndpc',
+      label: 'NDPC provider',
+    },
   ])('$label', ({ providerClass, contestType, contestId, title, abbreviationName }) => {
     test('expects to get correct metadata', () => {
       const provider = new providerClass(contestType);
diff --git a/src/features/tasks/utils/contest-table/dp_providers.ts b/src/features/tasks/utils/contest-table/dp_providers.ts
index 8d1d84c91..8ee49b01f 100644
--- a/src/features/tasks/utils/contest-table/dp_providers.ts
+++ b/src/features/tasks/utils/contest-table/dp_providers.ts
@@ -73,3 +73,36 @@ export class TDPCProvider extends ContestTableProviderBase {
     return '';
   }
 }
+
+export class NDPCProvider extends ContestTableProviderBase {
+  protected setFilterCondition(): (taskResult: TaskResult) => boolean {
+    return (taskResult: TaskResult) => {
+      if (classifyContest(taskResult.contest_id) !== this.contestType) {
+        return false;
+      }
+
+      return taskResult.contest_id === 'ndpc';
+    };
+  }
+
+  getMetadata(): ContestTableMetaData {
+    return {
+      title: 'Next DP Contest',
+      abbreviationName: 'ndpc',
+    };
+  }
+
+  getDisplayConfig(): ContestTableDisplayConfig {
+    return {
+      isShownHeader: false,
+      isShownRoundLabel: false,
+      roundLabelWidth: '',
+      tableBodyCellsWidth: 'w-1/2 xs:w-1/3 sm:w-1/4 md:w-1/5 lg:w-1/6 2xl:w-1/7 px-1 py-2',
+      isShownTaskIndex: true,
+    };
+  }
+
+  getContestRoundLabel(_contestId: string): string {
+    return '';
+  }
+}
diff --git a/src/test/lib/utils/task.test.ts b/src/test/lib/utils/task.test.ts
index 272fd3974..6c9f8c4f2 100644
--- a/src/test/lib/utils/task.test.ts
+++ b/src/test/lib/utils/task.test.ts
@@ -368,27 +368,27 @@ describe('Task', () => {
         {
           first: tasksForVerificationOfOrder.abc999_a,
           second: tasksForVerificationOfOrder.past202309_a,
-          expected: -5, // order: abc999_a, past202309_a
+          expected: -6, // order: abc999_a, past202309_a
         },
         {
           first: tasksForVerificationOfOrder.abc999_a,
           second: tasksForVerificationOfOrder.acl_a,
-          expected: -6, // order: abc999_a, acl_a
+          expected: -7, // order: abc999_a, acl_a
         },
         {
           first: tasksForVerificationOfOrder.abc999_a,
           second: tasksForVerificationOfOrder.joi2023_yo1c,
-          expected: -7, // order: abc999_a, joi2023_yo1c
+          expected: -8, // order: abc999_a, joi2023_yo1c
         },
         {
           first: tasksForVerificationOfOrder.abc999_a,
           second: tasksForVerificationOfOrder.tessoku_book_a,
-          expected: -8, // order: abc999_a, tessoku_book_a
+          expected: -9, // order: abc999_a, tessoku_book_a
         },
         {
           first: tasksForVerificationOfOrder.abc999_a,
           second: tasksForVerificationOfOrder.math_and_algorithm_a,
-          expected: -9, // order: abc999_a, math_and_algorithm_a
+          expected: -10, // order: abc999_a, math_and_algorithm_a
         },
       ];
 

From 34be160e5a8a8078583afacaf95e881aaf119154 Mon Sep 17 00:00:00 2001
From: "k.hiro1818" <k.hiro1818@gmail.com>
Date: Sun, 10 May 2026 06:12:49 +0000
Subject: [PATCH 3/6] fix: restore original contestTypePriorities comment
 categories

Revert to Educational/Genius/Special/External classification.
Update priority ranges after NDPC insertion at priority 6:
- Educational contests (0-11, 17)
- Contests for genius (12-16)
- Special contests (18-20)
- External platforms (21-23)

Also fix single-char lambda parameter in docs code example.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
---
 .../guides/how-to-add-contest-table-provider.md |  7 +++++--
 src/lib/utils/contest.ts                        | 10 +++++-----
 src/test/lib/utils/task.test.ts                 |  7 ++++++-
 src/test/lib/utils/test_cases/task_results.ts   | 17 ++++++++++++++++-
 4 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/docs/guides/how-to-add-contest-table-provider.md b/docs/guides/how-to-add-contest-table-provider.md
index 5eba16fa5..28886874c 100644
--- a/docs/guides/how-to-add-contest-table-provider.md
+++ b/docs/guides/how-to-add-contest-table-provider.md
@@ -265,12 +265,14 @@ class TessokuBookSectionProvider extends TessokuBookProvider {
 | -------------- | ------------- | ---------- | ------------ |
 | EDPC           | `'dp'`        | 26問       | A～Z         |
 | TDPC           | `'tdpc'`      | 26問       | A～Z         |
+| NDPC           | `'ndpc'`      | 20問       | A～T         |
 | FPS_24         | `'fps-24'`    | 24問       | A～X         |
 | ACL_PRACTICE   | `'practice2'` | 12問       | A～L         |
 | ACL_BEGINNER\* | `'abl'`       | 6問        | A～F         |
 | ACL_CONTEST1\* | `'acl1'`      | 6問        | A～F         |
 
 \*注: ACL_PRACTICE、ACL_BEGINNER、ACL_CONTEST1 は `Acl` グループの下で 3 つのコンテストが統一管理されています。
+\*\*注: EDPC・TDPC・NDPC・FPS 24 は `dps` グループ下で 4 つのコンテストが統一管理されています。
 
 ### 複合ソース型
 
@@ -317,7 +319,7 @@ describe('MyNewProvider', () => {
   test('filters tasks correctly', () => {
     const provider = new MyNewProvider(ContestType.MY_NEW);
     const filtered = provider.filter(taskResultsForMyNew);
-    expect(filtered.every((t) => t.contest_id === 'my-contest')).toBe(true);
+    expect(filtered.every((task) => task.contest_id === 'my-contest')).toBe(true);
   });
 
   test('returns correct metadata', () => {
@@ -532,6 +534,7 @@ describe('CustomProvider with unique config', () => {
 - [#2797](https://github.com/AtCoder-NoviSteps/AtCoderNoviSteps/issues/2797) - FPS24Provider
 - [#2920](https://github.com/AtCoder-NoviSteps/AtCoderNoviSteps/issues/2920)、[#3120](https://github.com/AtCoder-NoviSteps/AtCoderNoviSteps/issues/3120) - ACLPracticeProvider、ACLBeginnerProvider、ACLProvider
 - [#3152](https://github.com/AtCoder-NoviSteps/AtCoderNoviSteps/issues/3152) - JOISemiFinalRoundProvider（本選 → セミファイナルステージ への対応）
+- NDPC実装 - NDPCProvider（パターン2: 単一ソース型、prisma/tasks.ts に 20 問存在）
 
 ### 実装ファイル
 
@@ -541,4 +544,4 @@ describe('CustomProvider with unique config', () => {
 
 ---
 
-**最終更新**: 2026-02-22
+**最終更新**: 2026-05-10
diff --git a/src/lib/utils/contest.ts b/src/lib/utils/contest.ts
index eec49444b..ba291fe2f 100644
--- a/src/lib/utils/contest.ts
+++ b/src/lib/utils/contest.ts
@@ -252,13 +252,13 @@ export function getContestPrefixes(contestPrefixes: Record<string, string>) {
 }
 
 /**
- * Contest type priorities (0 = Highest, 21 = Lowest)
+ * Contest type priorities (0 = Highest, 23 = Lowest)
  *
  * Priority assignment rationale:
- * - Educational contests (0-10, 16): ABS, ABC, APG4B and AWC etc.
- * - Contests for genius (11-15): ARC, AGC, and their variants
- * - Special contests (17-19): UNIVERSITY, FPS_24, OTHERS
- * - External platforms (20-22): AOJ_COURSES, AOJ_PCK, AOJ_JAG
+ * - Educational contests (0-11, 17): ABS, ABC, APG4B and AWC etc.
+ * - Contests for genius (12-16): ARC, AGC, and their variants
+ * - Special contests (18-20): UNIVERSITY, FPS_24, OTHERS
+ * - External platforms (21-23): AOJ_COURSES, AOJ_PCK, AOJ_JAG
  *
  * @remarks
  * HACK: The priorities for ARC, AGC, UNIVERSITY, AOJ_COURSES, and AOJ_PCK are temporary
diff --git a/src/test/lib/utils/task.test.ts b/src/test/lib/utils/task.test.ts
index 6c9f8c4f2..e41680037 100644
--- a/src/test/lib/utils/task.test.ts
+++ b/src/test/lib/utils/task.test.ts
@@ -363,7 +363,12 @@ describe('Task', () => {
         {
           first: tasksForVerificationOfOrder.abc999_a,
           second: tasksForVerificationOfOrder.tdpc_contest,
-          expected: -4, // order: abc999_a, tpdc_contest
+          expected: -4, // order: abc999_a, tdpc_contest
+        },
+        {
+          first: tasksForVerificationOfOrder.abc999_a,
+          second: tasksForVerificationOfOrder.ndpc2026_a,
+          expected: -5, // order: abc999_a, ndpc2026_a
         },
         {
           first: tasksForVerificationOfOrder.abc999_a,
diff --git a/src/test/lib/utils/test_cases/task_results.ts b/src/test/lib/utils/test_cases/task_results.ts
index 565de0401..253ce4393 100644
--- a/src/test/lib/utils/test_cases/task_results.ts
+++ b/src/test/lib/utils/test_cases/task_results.ts
@@ -405,6 +405,20 @@ const tdpc_contest: TaskResult = {
   grade: 'PENDING',
   updated_at: new Date(),
 };
+const ndpc2026_a: TaskResult = {
+  is_ac: false,
+  user_id: userId2,
+  status_name: 'ns',
+  status_id: '4',
+  submission_status_image_path: 'ns.png',
+  submission_status_label_name: '未挑戦',
+  contest_id: 'ndpc',
+  task_table_index: 'A',
+  task_id: 'ndpc2026_a',
+  title: 'A. Polyomino',
+  grade: 'PENDING',
+  updated_at: new Date(),
+};
 const acl_a: TaskResult = {
   is_ac: false,
   user_id: userId2,
@@ -490,8 +504,9 @@ export const tasksForVerificationOfOrder = {
   typical90_a,
   dp_b,
   tdpc_contest,
-  acl_a,
+  ndpc2026_a,
   past202309_a,
+  acl_a,
   joi2023_yo1c,
   tessoku_book_a,
   math_and_algorithm_a,

From deaf44b9b5caea25bd1f8af24f41ce0ad946e8c0 Mon Sep 17 00:00:00 2001
From: "k.hiro1818" <k.hiro1818@gmail.com>
Date: Sun, 10 May 2026 06:46:00 +0000
Subject: [PATCH 4/6] docs: add add-contest-table-provider skill and
 documentation updates
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- Add /add-contest-table-provider skill with TDD-based implementation guide
- Add comprehensive checklist for 5-layer implementation (Prisma → types → utils → providers → groups)
- Document 3 implementation patterns (range filter, single source, composite)
- Update how-to-add-contest-table-provider with common mistake #5 (contestTypePriorities JSDoc categories)
- Update claude-code.md with new skill reference

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
---
 .../add-contest-table-provider/SKILL.md       |  13 ++
 .../instructions.md                           | 123 ++++++++++++++++++
 docs/guides/claude-code.md                    |  13 +-
 .../how-to-add-contest-table-provider.md      |  27 +++-
 4 files changed, 169 insertions(+), 7 deletions(-)
 create mode 100644 .claude/skills/add-contest-table-provider/SKILL.md
 create mode 100644 .claude/skills/add-contest-table-provider/instructions.md

diff --git a/.claude/skills/add-contest-table-provider/SKILL.md b/.claude/skills/add-contest-table-provider/SKILL.md
new file mode 100644
index 000000000..5df8a11d9
--- /dev/null
+++ b/.claude/skills/add-contest-table-provider/SKILL.md
@@ -0,0 +1,13 @@
+---
+name: add-contest-table-provider
+description: Add a new ContestType and ContestTableProvider across 5 layers using TDD. Covers all 3 patterns. Asks targeted questions to gather pattern-specific requirements before touching code.
+argument-hint: '<ContestType> <contest_id>'
+---
+
+Add a new contest table provider for: $ARGUMENTS
+
+> When in doubt at any step, use AskUserQuestion before proceeding.
+
+0. **Seed check** — grep `prisma/tasks.ts` for the contest_id(s); report count + task_ids; if absent or incomplete, ask the user to add missing rows (reference: `https://kenkoooo.com/atcoder/resources/problems.json`)
+1. **Gather requirements** — infer the implementation pattern; confirm per [instructions.md §Requirements](instructions.md)
+2. **Implement** — follow [instructions.md](instructions.md) for the confirmed pattern across 5 layers (TDD)
diff --git a/.claude/skills/add-contest-table-provider/instructions.md b/.claude/skills/add-contest-table-provider/instructions.md
new file mode 100644
index 000000000..28bdce16f
--- /dev/null
+++ b/.claude/skills/add-contest-table-provider/instructions.md
@@ -0,0 +1,123 @@
+# Add Contest Table Provider — Implementation Checklist
+
+Reference: `docs/guides/how-to-add-contest-table-provider.md`
+
+---
+
+## Requirements gathering
+
+Step 0 (seed check) is already done. Confirm the following before touching code:
+
+**All patterns:**
+
+- Which pattern? (State your inference from the data, ask to confirm)
+  - Pattern 1: numeric range filter (e.g. ABC 001–041)
+  - Pattern 2: single fixed contest_id (e.g. NDPC, TDPC, FPS_24)
+  - Pattern 3: multiple contest_ids unified in one table (e.g. ABS, ABC-Like)
+- Nearest neighbor ContestType for insertion order in `contestTypePriorities`?
+- New group or merge into existing? If new: group name / `buttonLabel` / `ariaLabel`?
+
+**Pattern 1 additional:**
+
+- Numeric range: start and end (open-ended if no upper bound)?
+- Shared problems with another contest (e.g. ARC–ABC overlap)? Which contest_ids appear in both?
+- Round label format (e.g. `ABC 042`)?
+
+**Pattern 3 additional:**
+
+- Show the full contest_id list found in `prisma/tasks.ts` — any missing or to exclude?
+- Does `prisma/contest_task_pairs.ts` need updating (shared task_ids across contests)?
+- task_table_index format: numeric (`001–`) or alphabetic (`A–`)?
+- Section splits needed? If yes: split key and section names?
+
+---
+
+## Layer 1 — Prisma schema
+
+- [ ] Add `XXX // Full Contest Name` to `prisma/schema.prisma` ContestType enum (after nearest neighbor)
+- [ ] `pnpm exec prisma generate` — non-interactive env; `migrate dev` requires interactive shell
+- [ ] `pnpm check` — expect a type error in `src/lib/types/contest.ts` (confirms client regenerated)
+
+## Layer 2 — TypeScript ContestType constant
+
+- [ ] Add `XXX: 'XXX', // Full Contest Name` to `ContestType` in `src/lib/types/contest.ts` (same position as schema)
+- [ ] `pnpm check` — error should be gone
+
+## Layer 3 — Contest utilities (TDD)
+
+### Write tests first
+
+- [ ] Add export to `src/test/lib/utils/test_cases/contest_type.ts` (after nearest neighbor)
+- [ ] Add export to `src/test/lib/utils/test_cases/contest_name_labels.ts` (after nearest neighbor)
+- [ ] Add three `describe('when contest_id is xxx')` blocks to `src/test/lib/utils/contest.test.ts`:
+  - under `classify contest`
+  - under `get contest priority`
+  - under `get contest name label`
+- [ ] `pnpm test:unit src/test/lib/utils/contest.test.ts` — **expect RED**
+
+### Implement
+
+- [ ] Add `classifyContest` branch after nearest neighbor's branch in `src/lib/utils/contest.ts`
+- [ ] Insert `[ContestType.XXX, N]` into `contestTypePriorities` after nearest neighbor
+  - All entries after the insertion point shift by +1
+  - **Update the JSDoc numeric ranges** — do NOT rename or split the existing four categories
+    (Educational / Contests for genius / Special contests / External platforms)
+  - **Search `src/test/lib/utils/task.test.ts` for hardcoded priority-diff expected values**
+    and decrement by 1 for every ContestType that shifted
+- [ ] Add `getContestNameLabel` branch after nearest neighbor's branch
+- [ ] `pnpm test:unit src/test/lib/utils/contest.test.ts` — **expect GREEN**
+
+---
+
+## Layer 4 — Provider class (TDD)
+
+### Pattern 2: single source
+
+- [ ] Add entry to `describe.each` array in `dp_providers.test.ts` (or the appropriate `*_providers.test.ts`)
+- [ ] Add import of new Provider class
+- [ ] `pnpm test:unit <providers.test.ts>` — **expect RED**
+- [ ] Implement Provider class in the appropriate `*_providers.ts` after nearest neighbor
+- [ ] `pnpm test:unit <providers.test.ts>` — **expect GREEN**
+
+### Pattern 1: range filter
+
+- [ ] Add test cases covering range boundaries and at least one mid-range value
+- [ ] If shared problems exist: add a test case with mixed contest_ids to confirm exclusion
+- [ ] `pnpm test:unit <providers.test.ts>` — **expect RED**
+- [ ] Implement Provider using `parseContestRound()` range check
+- [ ] `pnpm test:unit <providers.test.ts>` — **expect GREEN**
+
+### Pattern 3: composite
+
+- [ ] Confirm whether `prisma/contest_task_pairs.ts` needs new entries before writing tests
+- [ ] Add test cases for each constituent contest_id, plus a mixed-source test
+- [ ] If section splits: add one test per section
+- [ ] `pnpm test:unit <providers.test.ts>` — **expect RED**
+- [ ] Implement Provider (filter by `classifyContest` equality; add section subclasses if needed)
+- [ ] `pnpm test:unit <providers.test.ts>` — **expect GREEN**
+
+---
+
+## Layer 5 — Group registration (TDD)
+
+- [ ] Update `contest_table_provider_groups.test.ts`:
+  - New group name string, `buttonLabel`, `ariaLabel`
+  - `getSize()` incremented to reflect the new provider count
+  - Add `getProvider(ContestType.XXX)` assertion
+  - Add import of new Provider class
+- [ ] `pnpm test:unit contest_table_provider_groups.test.ts` — **expect RED**
+- [ ] Update `contest_table_provider_groups.ts`:
+  - Add import of new Provider class
+  - Update group name string, `buttonLabel`, `ariaLabel`
+  - Add `new XXXProvider(ContestType.XXX)` to `addProviders()`
+- [ ] `pnpm test:unit src/features/tasks/utils/contest-table/` — **expect GREEN**
+
+---
+
+## Final verification
+
+- [ ] `pnpm test:unit`
+- [ ] `pnpm check`
+- [ ] `pnpm lint`
+
+Commit Layer 1–3 and Layer 4–5 as separate commits.
diff --git a/docs/guides/claude-code.md b/docs/guides/claude-code.md
index 36314f313..dbd203b32 100644
--- a/docs/guides/claude-code.md
+++ b/docs/guides/claude-code.md
@@ -65,12 +65,13 @@ paths:
 
 **本プロジェクトの skills（`.claude/skills/` および superpowers plugin）:**
 
-| スキル           | 用途                                                                                                                               |
-| ---------------- | ---------------------------------------------------------------------------------------------------------------------------------- |
-| `/writing-plans` | 新機能・追加実装の詳細計画を生成（2-5分単位のタスク分解）。superpowers plugin 提供                                                 |
-| `/refactor-plan` | Issue 番号またはパスを渡してリファクタリング計画を出力（実装はしない）                                                             |
-| `/session-close` | セッション終了時のルーティン：テスト確認 → plan.md 更新 → rules 候補提示 → 肥大化チェック → 繰り返し指示検出                       |
-| `/dep-upgrade`   | ライブラリのメジャーバージョンアップ分析：破壊的変更の整理・本プロジェクトへの影響・新機能提案 → plan.md 生成 → アップグレード実行 |
+| スキル                        | 用途                                                                                                                                                            |
+| ----------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `/writing-plans`              | 新機能・追加実装の詳細計画を生成（2-5分単位のタスク分解）。superpowers plugin 提供                                                                              |
+| `/add-contest-table-provider` | 新しい ContestType と ContestTableProvider を TDD で 5 層実装（Prisma → 型 → ユーティリティ → Provider → グループ登録）。3 パターン対応。実装前に要件を確認する |
+| `/refactor-plan`              | Issue 番号またはパスを渡してリファクタリング計画を出力（実装はしない）                                                                                          |
+| `/session-close`              | セッション終了時のルーティン：テスト確認 → plan.md 更新 → rules 候補提示 → 肥大化チェック → 繰り返し指示検出                                                    |
+| `/dep-upgrade`                | ライブラリのメジャーバージョンアップ分析：破壊的変更の整理・本プロジェクトへの影響・新機能提案 → plan.md 生成 → アップグレード実行                              |
 
 **`/dep-upgrade` の使い方:**
 
diff --git a/docs/guides/how-to-add-contest-table-provider.md b/docs/guides/how-to-add-contest-table-provider.md
index 28886874c..cbf5dd60e 100644
--- a/docs/guides/how-to-add-contest-table-provider.md
+++ b/docs/guides/how-to-add-contest-table-provider.md
@@ -428,7 +428,7 @@ export const taskResultsForNewProvider: TaskResults = [
 
 ---
 
-## よくあるミス Top 4
+## よくあるミス Top 5
 
 ### 1. **getDisplayConfig() での属性漏れ**
 
@@ -504,6 +504,31 @@ describe('CustomProvider with unique config', () => {
 
 ---
 
+### 5. **contestTypePriorities の JSDoc カテゴリ名を変更してしまう**
+
+**問題**: 新しい ContestType を挿入して数値範囲が変わったとき、既存の4カテゴリ名
+（`Educational` / `Contests for genius` / `Special contests` / `External platforms`）を
+意図せず改名・分割・合体してしまい、歴史的経緯や分類上の意味が失われる。
+
+**解決策**: **カテゴリ名は絶対に変更しない**。変えてよいのは括弧内の数値範囲だけ。
+
+```typescript
+// Before: [ContestType.TDPC, 5] ... [ContestType.PAST, 6]
+// After inserting NDPC at 6:
+//   [ContestType.NDPC, 6], [ContestType.PAST, 7], ...
+
+// ✅ 数値範囲だけ更新
+// Educational contests (0–11, 17)
+// Contests for genius (12–16)
+// Special contests (18–20)
+// External platforms (21–23)
+
+// ❌ カテゴリを改名・分割・合体しない
+// Educational / DP contests (0–6)   ← NG
+```
+
+---
+
 ## 実装完了後
 
 ### ドキュメント更新チェックリスト

From cc14e72a6388cd8d58b6fa7a4260187bb4465637 Mon Sep 17 00:00:00 2001
From: "k.hiro1818" <k.hiro1818@gmail.com>
Date: Sun, 10 May 2026 08:10:01 +0000
Subject: [PATCH 5/6] feat: add NDPC to ContestType enum and fix
 atcoder_account updatedAt default

- Add NDPC (National Informatics Olympiad - Domestic Programming Contest) to ContestType
- Fix atcoder_account.updatedAt to drop incorrect DEFAULT CURRENT_TIMESTAMP (managed by Prisma @updatedAt)

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
---
 .../migration.sql                                             | 4 ++++
 .../20260510080034_add_ndpc_to_contest_type/migration.sql     | 2 ++
 2 files changed, 6 insertions(+)
 create mode 100644 prisma/migrations/20260510075743_fix_atcoder_account_updated_at_default/migration.sql
 create mode 100644 prisma/migrations/20260510080034_add_ndpc_to_contest_type/migration.sql

diff --git a/prisma/migrations/20260510075743_fix_atcoder_account_updated_at_default/migration.sql b/prisma/migrations/20260510075743_fix_atcoder_account_updated_at_default/migration.sql
new file mode 100644
index 000000000..fb8dca5be
--- /dev/null
+++ b/prisma/migrations/20260510075743_fix_atcoder_account_updated_at_default/migration.sql
@@ -0,0 +1,4 @@
+-- @updatedAt is managed by Prisma ORM, not the DB layer. The original
+-- split_atcoder_account migration incorrectly added DEFAULT CURRENT_TIMESTAMP
+-- to updatedAt. This migration aligns the migration history with the actual DB state.
+ALTER TABLE "atcoder_account" ALTER COLUMN "updatedAt" DROP DEFAULT;
diff --git a/prisma/migrations/20260510080034_add_ndpc_to_contest_type/migration.sql b/prisma/migrations/20260510080034_add_ndpc_to_contest_type/migration.sql
new file mode 100644
index 000000000..42b043535
--- /dev/null
+++ b/prisma/migrations/20260510080034_add_ndpc_to_contest_type/migration.sql
@@ -0,0 +1,2 @@
+-- AlterEnum
+ALTER TYPE "ContestType" ADD VALUE 'NDPC';

From c057e8a911fae7de88e5789c01598886d853b536 Mon Sep 17 00:00:00 2001
From: "k.hiro1818" <k.hiro1818@gmail.com>
Date: Sun, 10 May 2026 08:11:34 +0000
Subject: [PATCH 6/6] chore: remove completed NDPC implementation plan

Plan implementation is complete. Archive plan per AGENTS.md guidelines.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
---
 .../add-ndpc-contest-table-provider/plan.md   | 442 ------------------
 1 file changed, 442 deletions(-)
 delete mode 100644 docs/dev-notes/2026-05-10/add-ndpc-contest-table-provider/plan.md

diff --git a/docs/dev-notes/2026-05-10/add-ndpc-contest-table-provider/plan.md b/docs/dev-notes/2026-05-10/add-ndpc-contest-table-provider/plan.md
deleted file mode 100644
index 1e17e810f..000000000
--- a/docs/dev-notes/2026-05-10/add-ndpc-contest-table-provider/plan.md
+++ /dev/null
@@ -1,442 +0,0 @@
-# Next DP Contest (NDPC) コンテストテーブル追加 実装計画
-
-**Goal:** コンテストテーブルに Next DP Contest (NDPC) を追加し、EDPC・TDPC・FPS 24 グループに統合する。
-
-**Architecture:** `ContestType.NDPC` を Prisma スキーマ → TypeScript 定数 → `classifyContest` / `contestTypePriorities` / `getContestNameLabel` → `NDPCProvider` → `dps` グループの順に追加する。TDD で各レイヤーを実装する。
-
-**Tech Stack:** Prisma (PostgreSQL enum), TypeScript, Vitest
-
----
-
-## Context
-
-問題データ (`prisma/tasks.ts` 6349–6488 行) はすでに存在する (`contest_id: 'ndpc'`、問題 A–T の 20 問)。しかし `ContestType.NDPC` が未定義のため、コンテストテーブル上に表示されない。ユーザー指定の仕様：
-
-- 順番: `TDPC` の直後に配置
-- `dps` グループの buttonLabel: `EDPC・TDPC・NDPC・FPS 24`
-
-## 設計の根拠
-
-- `NDPCProvider` は `TDPCProvider` と同じ Pattern 2 (Single Source) — `contest_id === 'ndpc'` による単一フィルター
-- `contestTypePriorities` に NDPC=6 を割り当て、以後のエントリを全て1ずつ上げる (PAST=7, ACL_PRACTICE=8, ..., AOJ_JAG=23)
-  - 理由: 整数優先度の一貫性を保つ。浮動小数点は保守性を損なう。
-- `dp_providers.ts` に同居させることで DP 系プロバイダーをひとつのファイルに集約する (EDPC・TDPC と同じ理由)
-
-## 却下した代替案
-
-- **独立ファイル `ndpc_provider.ts` に分離**: DP 系は `dp_providers.ts` に集約する既存慣習に反する。問題数の違いはプロバイダー実装に影響しない。
-
----
-
-## 変更ファイル一覧
-
-| ファイル                                                                       | 操作                                                                             |
-| ------------------------------------------------------------------------------ | -------------------------------------------------------------------------------- |
-| `prisma/schema.prisma`                                                         | `ContestType` enum に `NDPC` 追加                                                |
-| `src/lib/types/contest.ts`                                                     | `ContestType` オブジェクトに `NDPC` 追加                                         |
-| `src/lib/utils/contest.ts`                                                     | `classifyContest` / `contestTypePriorities` / `getContestNameLabel` に NDPC 追記 |
-| `src/test/lib/utils/test_cases/contest_type.ts`                                | `ndpc` テストケース追加                                                          |
-| `src/test/lib/utils/test_cases/contest_name_labels.ts`                         | `ndpc` テストケース追加                                                          |
-| `src/test/lib/utils/contest.test.ts`                                           | 3 つの `describe` ブロック追加                                                   |
-| `src/features/tasks/utils/contest-table/dp_providers.ts`                       | `NDPCProvider` クラス追加                                                        |
-| `src/features/tasks/utils/contest-table/dp_providers.test.ts`                  | NDPC をパラメータ化テストに追加                                                  |
-| `src/features/tasks/utils/contest-table/contest_table_provider_groups.ts`      | `dps` プリセット更新                                                             |
-| `src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts` | `dps` テスト更新                                                                 |
-
----
-
-## Task 1: Prisma スキーマ + マイグレーション
-
-**Files:**
-
-- Modify: `prisma/schema.prisma:307`
-
-- [ ] **Step 1: schema.prisma を編集**
-
-`TDPC // Typical DP Contest` の直後に追加：
-
-```prisma
-NDPC // Next DP Contest
-```
-
-- [ ] **Step 2: マイグレーション実行**
-
-```bash
-pnpm exec prisma migrate dev --name add_ndpc_to_contest_type
-```
-
-Expected: `Your database is now in sync with your schema.` のようなメッセージ。`@prisma/client` が再生成され `ContestTypeOrigin` に `NDPC` が含まれる。
-
-- [ ] **Step 3: 型チェック**
-
-```bash
-pnpm check
-```
-
-Expected: `src/lib/types/contest.ts` で型エラー（`NDPC` がオブジェクトに無い）。これは Task 2 で修正する。
-
----
-
-## Task 2: TypeScript ContestType 定数更新
-
-**Files:**
-
-- Modify: `src/lib/types/contest.ts:37`
-
-- [ ] **Step 1: NDPC を追加**
-
-```typescript
-NDPC: 'NDPC', // Next DP Contest
-```
-
-`TDPC: 'TDPC', // Typical DP Contest` の直後に挿入。
-
-- [ ] **Step 2: 型チェック**
-
-```bash
-pnpm check
-```
-
-Expected: エラーなし（または NDPC 未使用の警告のみ）。
-
----
-
-## Task 3: classifyContest / contestTypePriorities / getContestNameLabel 更新 (TDD)
-
-**Files:**
-
-- Modify: `src/test/lib/utils/test_cases/contest_type.ts`
-- Modify: `src/test/lib/utils/test_cases/contest_name_labels.ts`
-- Modify: `src/test/lib/utils/contest.test.ts`
-- Modify: `src/lib/utils/contest.ts`
-
-- [ ] **Step 1: テストケースデータを追加 (contest_type.ts)**
-
-`tdpc` エクスポートの直後に追加：
-
-```typescript
-export const ndpc = [
-  createTestCaseForContestType('NDPC')({
-    contestId: 'ndpc',
-    expected: ContestType.NDPC,
-  }),
-];
-```
-
-- [ ] **Step 2: テストケースデータを追加 (contest_name_labels.ts)**
-
-`tdpc` エクスポートの直後に追加：
-
-```typescript
-export const ndpc = [
-  createTestCaseForContestNameLabel('NDPC')({
-    contestId: 'ndpc',
-    expected: 'NDPC',
-  }),
-];
-```
-
-- [ ] **Step 3: describe ブロックを追加 (contest.test.ts)**
-
-`classifyContest`・`getContestPriority`・`getContestNameLabel` の各 `when contest_id is tdpc` describe の直後に、それぞれ以下を追加：
-
-```typescript
-describe('when contest_id is ndpc', () => {
-  TestCasesForContestType.ndpc.forEach(({ name, value }) => {
-    runTests(`${name}`, [value], ({ contestId, expected }: TestCaseForContestType) => {
-      expect(classifyContest(contestId)).toEqual(expected);
-    });
-  });
-});
-```
-
-```typescript
-describe('when contest_id is ndpc', () => {
-  TestCasesForContestType.ndpc.forEach(({ name, value }) => {
-    runTests(`${name}`, [value], ({ contestId, expected }: TestCaseForContestType) => {
-      expect(getContestPriority(contestId)).toEqual(contestTypePriorities.get(expected));
-    });
-  });
-});
-```
-
-```typescript
-describe('when contest_id is ndpc', () => {
-  TestCasesForContestNameLabel.ndpc.forEach(({ name, value }) => {
-    runTests(`${name}`, [value], ({ contestId, expected }: TestCaseForContestNameLabel) => {
-      expect(getContestNameLabel(contestId)).toEqual(expected);
-    });
-  });
-});
-```
-
-- [ ] **Step 4: テスト失敗を確認**
-
-```bash
-pnpm test:unit src/test/lib/utils/contest.test.ts
-```
-
-Expected: NDPC 関連テストが FAIL。
-
-- [ ] **Step 5: contest.ts を実装**
-
-`classifyContest` — `if (contest_id === 'tdpc')` ブロックの直後に追加：
-
-```typescript
-if (contest_id === 'ndpc') {
-  return ContestType.NDPC;
-}
-```
-
-`contestTypePriorities` — 全体の優先度を調整：
-
-- `[ContestType.NDPC, 6]` を TDPC の直後に追加
-- 以後のエントリを全て 1 ずつ上げる (PAST: 6→7, ACL_PRACTICE: 7→8, ..., AOJ_JAG: 22→23)
-
-新しい優先度マップ:
-
-```typescript
-[ContestType.ABS, 0],
-[ContestType.ABC, 1],
-[ContestType.APG4B, 2],
-[ContestType.TYPICAL90, 3],
-[ContestType.EDPC, 4],
-[ContestType.TDPC, 5],
-[ContestType.NDPC, 6],        // <- 新規
-[ContestType.PAST, 7],        // <- 6→7
-[ContestType.ACL_PRACTICE, 8], // <- 7→8
-[ContestType.JOI, 9],         // <- 8→9
-[ContestType.TESSOKU_BOOK, 10], // <- 9→10
-[ContestType.MATH_AND_ALGORITHM, 11], // <- 10→11
-[ContestType.ARC, 12],        // <- 11→12
-[ContestType.AGC, 13],        // <- 12→13
-[ContestType.ABC_LIKE, 14],   // <- 13→14
-[ContestType.ARC_LIKE, 15],   // <- 14→15
-[ContestType.AGC_LIKE, 16],   // <- 15→16
-[ContestType.AWC, 17],        // <- 16→17
-[ContestType.UNIVERSITY, 18], // <- 17→18
-[ContestType.FPS_24, 19],     // <- 18→19
-[ContestType.OTHERS, 20],     // <- 19→20
-[ContestType.AOJ_COURSES, 21], // <- 20→21
-[ContestType.AOJ_PCK, 22],    // <- 21→22
-[ContestType.AOJ_JAG, 23],    // <- 22→23
-```
-
-`getContestNameLabel` — `if (contestId === 'tdpc') { return 'TDPC'; }` の直後に追加：
-
-```typescript
-if (contestId === 'ndpc') {
-  return 'NDPC';
-}
-```
-
-- [ ] **Step 6: テスト通過を確認**
-
-```bash
-pnpm test:unit src/test/lib/utils/contest.test.ts
-```
-
-Expected: すべて PASS。
-
-- [ ] **Step 7: コミット**
-
-```bash
-git add prisma/schema.prisma prisma/migrations/ src/lib/types/contest.ts src/lib/utils/contest.ts src/test/lib/utils/test_cases/contest_type.ts src/test/lib/utils/test_cases/contest_name_labels.ts src/test/lib/utils/contest.test.ts
-git commit -m "feat: add NDPC ContestType with classifyContest and name label support"
-```
-
----
-
-## Task 4: NDPCProvider 実装 (TDD)
-
-**Files:**
-
-- Modify: `src/features/tasks/utils/contest-table/dp_providers.test.ts`
-- Modify: `src/features/tasks/utils/contest-table/dp_providers.ts`
-
-- [ ] **Step 1: テストを追加 (dp_providers.test.ts)**
-
-`describe.each` の配列に NDPC エントリを追加：
-
-```typescript
-{
-  providerClass: NDPCProvider,
-  contestType: ContestType.NDPC,
-  contestId: 'ndpc',
-  title: 'Next DP Contest',
-  abbreviationName: 'ndpc',
-  label: 'NDPC provider',
-},
-```
-
-import 行も更新：
-
-```typescript
-import { EDPCProvider, TDPCProvider, NDPCProvider } from './dp_providers';
-```
-
-- [ ] **Step 2: テスト失敗を確認**
-
-```bash
-pnpm test:unit src/features/tasks/utils/contest-table/dp_providers.test.ts
-```
-
-Expected: `NDPCProvider` が未定義で FAIL。
-
-- [ ] **Step 3: NDPCProvider を実装 (dp_providers.ts)**
-
-`TDPCProvider` クラスの直後に追加：
-
-```typescript
-export class NDPCProvider extends ContestTableProviderBase {
-  protected setFilterCondition(): (taskResult: TaskResult) => boolean {
-    return (taskResult: TaskResult) => {
-      if (classifyContest(taskResult.contest_id) !== this.contestType) {
-        return false;
-      }
-
-      return taskResult.contest_id === 'ndpc';
-    };
-  }
-
-  getMetadata(): ContestTableMetaData {
-    return {
-      title: 'Next DP Contest',
-      abbreviationName: 'ndpc',
-    };
-  }
-
-  getDisplayConfig(): ContestTableDisplayConfig {
-    return {
-      isShownHeader: false,
-      isShownRoundLabel: false,
-      roundLabelWidth: '',
-      tableBodyCellsWidth: 'w-1/2 xs:w-1/3 sm:w-1/4 md:w-1/5 lg:w-1/6 2xl:w-1/7 px-1 py-2',
-      isShownTaskIndex: true,
-    };
-  }
-
-  getContestRoundLabel(_contestId: string): string {
-    return '';
-  }
-}
-```
-
-- [ ] **Step 4: テスト通過を確認**
-
-```bash
-pnpm test:unit src/features/tasks/utils/contest-table/dp_providers.test.ts
-```
-
-Expected: すべて PASS。
-
----
-
-## Task 5: dps グループに NDPCProvider を登録
-
-**Files:**
-
-- Modify: `src/features/tasks/utils/contest-table/contest_table_provider_groups.ts:26,187-195`
-- Modify: `src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts`
-
-- [ ] **Step 1: テストを更新 (contest_table_provider_groups.test.ts)**
-
-`expects to create DPs preset correctly` テストを更新：
-
-```typescript
-test('expects to create DPs preset correctly', () => {
-  const group = prepareContestProviderPresets().dps();
-
-  expect(group.getGroupName()).toBe('EDPC・TDPC・NDPC・FPS 24');
-  expect(group.getMetadata()).toEqual({
-    buttonLabel: 'EDPC・TDPC・NDPC・FPS 24',
-    ariaLabel: 'EDPC, TDPC, NDPC and FPS 24 contests',
-  });
-  expect(group.getSize()).toBe(4);
-  expect(group.getProvider(ContestType.EDPC)).toBeInstanceOf(EDPCProvider);
-  expect(group.getProvider(ContestType.TDPC)).toBeInstanceOf(TDPCProvider);
-  expect(group.getProvider(ContestType.NDPC)).toBeInstanceOf(NDPCProvider);
-  expect(group.getProvider(ContestType.FPS_24)).toBeInstanceOf(FPS24Provider);
-});
-```
-
-import 行に `NDPCProvider` を追加。
-
-- [ ] **Step 2: テスト失敗を確認**
-
-```bash
-pnpm test:unit src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts
-```
-
-Expected: グループ名・サイズ・NDPC provider のアサーションが FAIL。
-
-- [ ] **Step 3: contest_table_provider_groups.ts を更新**
-
-import 行を更新：
-
-```typescript
-import { EDPCProvider, TDPCProvider, NDPCProvider } from './dp_providers';
-```
-
-`dps` プリセットを更新：
-
-```typescript
-dps: () =>
-  new ContestTableProviderGroup(`EDPC・TDPC・NDPC・FPS 24`, {
-    buttonLabel: 'EDPC・TDPC・NDPC・FPS 24',
-    ariaLabel: 'EDPC, TDPC, NDPC and FPS 24 contests',
-  }).addProviders(
-    new EDPCProvider(ContestType.EDPC),
-    new TDPCProvider(ContestType.TDPC),
-    new NDPCProvider(ContestType.NDPC),
-    new FPS24Provider(ContestType.FPS_24),
-  ),
-```
-
-- [ ] **Step 4: テスト通過を確認**
-
-```bash
-pnpm test:unit src/features/tasks/utils/contest-table/
-```
-
-Expected: すべて PASS。
-
-- [ ] **Step 5: 全テストを実行**
-
-```bash
-pnpm test:unit
-```
-
-Expected: すべて PASS。
-
-- [ ] **Step 6: 型チェック**
-
-```bash
-pnpm check
-```
-
-Expected: エラーなし。
-
-- [ ] **Step 7: コミット**
-
-```bash
-git add src/features/tasks/utils/contest-table/dp_providers.ts src/features/tasks/utils/contest-table/dp_providers.test.ts src/features/tasks/utils/contest-table/contest_table_provider_groups.ts src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts
-git commit -m "feat: add NDPCProvider and register in dps contest group"
-```
-
----
-
-## Verification
-
-```bash
-# 全テスト
-pnpm test:unit
-
-# 型チェック
-pnpm check
-
-# lint
-pnpm lint
-```
-
-期待動作: `pnpm dev` 起動後、コンテストテーブルのフィルターに `EDPC・TDPC・NDPC・FPS 24` ボタンが表示され、NDPC の 20 問 (A–T) が表示される。