From 41397db9467fabbc8a812d9cc4dccf2297be80bb Mon Sep 17 00:00:00 2001
From: sh0723 <pshpark12345@naver.com>
Date: Thu, 25 Jun 2026 15:18:41 +0900
Subject: [PATCH] =?UTF-8?q?1987=20:=20=EC=95=8C=ED=8C=8C=EB=B2=B3=20solve?=
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---
 src/week3/BOJ1987/BOJ1987_V1.cpp | 46 ++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 src/week3/BOJ1987/BOJ1987_V1.cpp

diff --git a/src/week3/BOJ1987/BOJ1987_V1.cpp b/src/week3/BOJ1987/BOJ1987_V1.cpp
new file mode 100644
index 0000000..9000b5d
--- /dev/null
+++ b/src/week3/BOJ1987/BOJ1987_V1.cpp
@@ -0,0 +1,46 @@
+#include <bits/stdc++.h>
+using namespace std;
+int inp[20][20], visited[20][20];
+int dy[4] = {0,0,1,-1};
+int dx[4] = {1,-1,0,0};
+map<int,int> ret;
+int R,C;
+int max_val = INT_MIN;
+void dfs(int y, int x, int level) {
+    visited[y][x] = 1;
+    ret[inp[y][x]] = 1;
+    for (int i = 0; i < 4; i++) {
+        int ny = y + dy[i];
+        int nx = x + dx[i];
+
+        if (ny < 0 || ny >= R || nx < 0 || nx >= C) continue;
+        if (visited[ny][nx]) continue;
+
+        if (ret.find(inp[ny][nx]) != ret.end()) continue;
+        dfs(ny, nx, level + 1);
+    }
+    visited[y][x] = 0;
+    ret.erase(inp[y][x]);
+    max_val = max(max_val, level);
+}
+int main() {
+
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+
+    cin >> R >> C;
+
+    for (int i=0; i<R; i++) {
+        string s;
+        cin >> s;
+        for (int j=0; j<C; j++) {
+            inp[i][j] = s[j] - 'A';
+        }
+    }
+    ret[inp[0][0]] = 1;
+    dfs(0,0,1);
+
+    cout << max_val << '\n';
+    return 0;
+}
\ No newline at end of file