[20250630] BOJ / G4 / RGB거리 2 / 설진영

Seol-JY/202506/30 BOJ G4 RGB거리 2.md

@@ -0,0 +1,51 @@
+```java
+import java.io.*;
+import java.util.*; 
+
+public class Main {
+    static final int RED = 0;
+    static final int GREEN = 1;
+    static final int BLUE = 2;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int n = Integer.parseInt(br.readLine());
+
+        int[][] cost = new int[n][3];
+        for (int i = 0; i < n; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            cost[i][RED] = Integer.parseInt(st.nextToken());
+            cost[i][GREEN] = Integer.parseInt(st.nextToken());
+            cost[i][BLUE] = Integer.parseInt(st.nextToken());
+        }
+
+        int answer = 987654321;
+
+        for (int firstColor = 0; firstColor < 3; firstColor++) {
+            int[][] dp = new int[n][3];
+
+            for (int j = 0; j < 3; j++) {
+                if (j == firstColor) {
+                    dp[0][j] = cost[0][j];
+                } else {
+                    dp[0][j] = 987654321;
+                }
+            }
+
+            for (int i = 1; i < n; i++) {
+                dp[i][RED] = Math.min(dp[i-1][GREEN], dp[i-1][BLUE]) + cost[i][RED];
+                dp[i][GREEN] = Math.min(dp[i-1][RED], dp[i-1][BLUE]) + cost[i][GREEN];
+                dp[i][BLUE] = Math.min(dp[i-1][RED], dp[i-1][GREEN]) + cost[i][BLUE];
+            }
+
+            for (int j = 0; j < 3; j++) {
+                if (j != firstColor) {
+                    answer = Math.min(answer, dp[n-1][j]);
+                }
+            }
+        }
+
+        System.out.println(answer);
+    }
+}
+```