배수빈: [BOJ] 1749 점수 따먹기_241205

Author: baexxbin

BOJ/1000-5000번/SB_1749.java

@@ -0,0 +1,45 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+public class SB_1749 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        int N = Integer.parseInt(st.nextToken());
+        int M = Integer.parseInt(st.nextToken());
+
+        int[][] board = new int[N][M];
+        long[][] dp = new long[N + 1][M + 1];
+        for (int i = 0; i < N; i++) {
+            st = new StringTokenizer(br.readLine());
+            for (int j = 0; j < M; j++) {
+                board[i][j] = Integer.parseInt(st.nextToken());
+            }
+        }
+
+        // 누적합 계산
+        for (int i = 1; i < N + 1; i++) {
+            for (int j = 1; j < M + 1; j++) {
+                dp[i][j] = board[i-1][j-1] + dp[i - 1][j] + dp[i][j - 1] - dp[i - 1][j - 1];
+            }
+        }
+
+        // 부분 행렬의 최대값 찾기
+        long mx = Long.MIN_VALUE;
+        for (int r1 = 1; r1 < N + 1; r1++) {
+            for (int c1 = 1; c1 <= M + 1; c1++) {
+                for (int r2 = r1; r2 <= N; r2++) {
+                    for (int c2 = c1; c2 <= M; c2++) {
+                        long tmp = dp[r2][c2] - dp[r1 - 1][c2] - dp[r2][c1 - 1] + dp[r1 - 1][c1 - 1];
+                        mx = Math.max(mx, tmp);
+                    }
+                }
+            }
+        }
+
+        System.out.println(mx);
+    }
+}