dalao帮查错QWQ

#include<bits/stdc++.h>
using namespace std;
int m,n;
int a[2501][2501],f[2501][2501]={0},g[2501][2501]={0};
int ans=-1e9;
int main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            cin>>a[i][j];
            f[i][j]=a[i][j];
            g[i][j]=a[i][j];
        }
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            if(a[i][j]==1){
                f[i][j]=f[i-1][j-1]+1;
                for(int k=i-1;k>=i-f[i-1][j-1];k--){
                    if(a[k][j]==1){
                        f[i][j]=1;
                        break;
                    }
                }
                for(int k=j-1;k>=j-f[i-1][j-1];k--){
                    if(a[i][k]==1){
                        f[i][j]=1;
                        break;
                    }
                }
            }
            //cout<<f[i][j]<<" ";
            //if(f[i][j]>ans)ans=f[i][j];
        }
        //cout<<endl;
    }
    for(int i=1;i<=n;i++){
        for(int j=m;j>=1;j--){
            if(a[i][j]==1){
                g[i][j]=g[i-1][j+1]+1;
                for(int k=i-1;k>=i-g[i-1][j+1];k--){
                    if(a[k][j]==1){
                        g[i][j]=1;
                        break;
                    }
                }
                for(int k=j+1;k<=j+g[i-1][j+1];k++){
                    if(a[i][k]==1){
                        g[i][j]=1;
                        break;
                    }
                }
            }
            //cout<<f[i][j]<<" ";
            //if(f[i][j]>ans)ans=f[i][j];
        }
        //cout<<endl;
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            //cout<<f[i][j]<<" "; 
            if(f[i][j]>ans){
                ans=f[i][j];
            }
        }
        //cout<<endl;
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            //cout<<g[i][j]<<" "; 
            if(g[i][j]>ans){
                ans=g[i][j];
            }
        }
        //cout<<endl;
    }
    cout<<ans;
    return 0;
}