p1387 最大正方形

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<vector>
#define N 6001
using namespace std;
typedef long long ll ;
int dp[N][N];
int ()
{
    int m, n;
    cin >> m >> n;
    int ans = 0;
    for (int i = 1; i <= m;i++)
    {
        for (int j = 1; j <= n;j++)
        {
            int a;
            cin >> a;
            if(!a)
                continue;
            dp[i][j]=min(min(dp[i-1][j],dp[i][j-1]),dp[i-1][j-1])+1;
            
            ans = max(ans, dp[i][j]);
        }
    }
    cout << ans << endl;
}