求找错。。。。。p1736

#include<bits/stdc++.h>
using namespace std;
int f[2505][2505];
int n,m;
int gao[2505];
int leftt[2505];
int q;
int ans;
int rightt[2505];

int mapp[2505][2505];

int main()
{
    cin>>n>>m;
    for(int i=1;i<=n;i++)
       for(int j=1;j<=m;j++)
       {
            cin>>q;
            mapp[i][j]=q;
            if(q==0)
            {
                gao[j]=gao[j]+1;
                leftt[j]=leftt[j-1]+1;
            }      

            if(q==1)
            {
                f[i][j]=min(f[i-1][j-1]+1,min(gao[j]+1,leftt[j-1]+1));
                gao[j]=0;
                leftt[j]=0;
                ans=max(ans,f[i][j]);
            }
       }
    memset(gao,0,sizeof(gao));
    memset(f,0,sizeof(f));
    for(int i=1;i<=n;i++)
       for(int j=n;j>=1;j--)
         {
            if(mapp[i][j]==0)
            {
                gao[j]=gao[j]+1;
                rightt[j]=rightt[j+1]+1;
            }

            if(mapp[i][j]==1)
            {
                f[i][j]=min(f[i-1][j+1]+1,min(gao[j]+1,rightt[j+1]+1));
                gao[j]=0;
                rightt[j]=0;
                ans=max(ans,f[i][j]);

            }
         }

    cout<<ans;
}