Lang:G++
Edit12345678910111213141516171819202122232425262728293031#include <stdio.h>#include <iostream>#include <algorithm>#include <string.h>using namespace std;#define LL long longconst int N = 2e5+55;char aa[501][501];int a[555][555];int main(){int n;cin>>n;for(int i=1;i<=n;i++){for(int j=1;j<=n;j++){cin>>aa[i][j];a[i][j]=aa[i][j]=='1';}}int ans=0;for(int i=1;i<=n;i++){for(int j=1;j<=n;j++){int b = 0;while(a[i-b][j]==1&&a[i+b][j]==1&&a[i][j-b]==1&&a[i][j+b]==1){b++;}ans=max(ans,b-1);}