『题解』A22743.创意吃鱼法

特别注意：该题目内存限制在了128M，所以变量需开小点（蒟蒻第一次提交开太大了

这边是90分代码，MLE一个点，自己看着改吧

#include <bits/stdc++.h>
using namespace std;
const int maxn = 3e3 + 7;
int n, m, ans;
int c[maxn][maxn];
int heng[maxn][maxn];
int shu[maxn][maxn];
int dp1[maxn][maxn];
int dp2[maxn][maxn];
int main() {
	cin >> n >> m;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			cin >> c[i][j];
			if (!c[i][j]) {
				heng[i][j] = heng[i][j - 1] + 1;
				shu[i][j] = shu[i - 1][j] + 1;
			} else {
				dp1[i][j] = min(dp1[i - 1][j - 1], min(heng[i][j - 1], shu[i- 1][j])) + 1;
				ans = max(ans, dp1[i][j]);
			}
		}
	}
	memset(heng, 0, sizeof(heng));
	for (int i = 1; i <= n; i++) {
		for (int j = m; j >= 1; j--) {
			if (!c[i][j]) {
				heng[i][j] = heng[i][j + 1] + 1;
			} else {
				dp2[i][j] = min(dp2[i - 1][j + 1], min(heng[i][j + 1], shu[i - 1][j])) + 1;
				ans = max(ans, dp2[i][j]);
			}
		}
	}
	cout << ans << endl;
	return 0;
}