Merge pull request #1846 from AlgorithmWithGod/ksinji

[20260127] BOJ / G4 / RGB거리 2 / 강신지

Author: ShinHeeEul

ksinji/202601/27 BOJ RGB거리 2.md

@@ -0,0 +1,55 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static int n;
+    static int[][] cost;
+    static int[][] dp;
+
+    static final int INF = 1_000_000_000;
+
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st;
+
+        n = Integer.parseInt(br.readLine());
+        cost = new int[n][3];
+
+        for (int i = 0; i < n; i++) {
+            st = new StringTokenizer(br.readLine());
+            cost[i][0] = Integer.parseInt(st.nextToken());
+            cost[i][1] = Integer.parseInt(st.nextToken());
+            cost[i][2] = Integer.parseInt(st.nextToken());
+        }
+
+        int ans = INF;
+
+        for (int firstColor = 0; firstColor < 3; firstColor++) {
+            dp = new int[n][3];
+
+            for (int c = 0; c < 3; c++) {
+                if (c == firstColor) {
+                    dp[0][c] = cost[0][c];
+                } else {
+                    dp[0][c] = INF;
+                }
+            }
+
+            for (int i = 1; i < n; i++) {
+                dp[i][0] = Math.min(dp[i - 1][1], dp[i - 1][2]) + cost[i][0];
+                dp[i][1] = Math.min(dp[i - 1][0], dp[i - 1][2]) + cost[i][1];
+                dp[i][2] = Math.min(dp[i - 1][0], dp[i - 1][1]) + cost[i][2];
+            }
+
+            for (int lastColor = 0; lastColor < 3; lastColor++) {
+                if (lastColor != firstColor) {
+                    ans = Math.min(ans, dp[n - 1][lastColor]);
+                }
+            }
+        }
+
+        System.out.println(ans);
+```
+    }
+}