P1565 牛宫

https://www.luogu.com.cn/record/83999075

Luogu/P1565/P1565.cpp

@@ -0,0 +1,42 @@
+#include <iostream>
+#include <cmath>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 205;
+
+int n, m;
+long long g[N][N], ans;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> m;
+
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1; j <= m; j++) {
+            cin >> g[i][j];
+
+            g[i][j] += g[i - 1][j] + g[i][j - 1] - g[i - 1][j - 1];
+        }
+    }
+
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1; j <= m; j++) {
+            for (int k = i; k <= n; k++) {
+                for (int l = j; l <= m; l++) {
+                    if (g[k][l] - g[k][j - 1] - g[i - 1][l] + g[i - 1][j - 1] >= 0) {
+                        ans = std::max(ans, static_cast<long long>(k - i + 1) * (l - j + 1));
+                    }
+                }
+            }
+        }
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}