codeforces 356C Bear and Square Grid

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <iostream>

using namespace std;
char mp[510][510];
int vis[510][510];
int are_num[510][510];
int sum[510][510];
int are_vis[250000];
int main()
{
    int n,k;
    scanf ("%d%d",&n,&k);
    memset(mp,‘#‘,sizeof(mp));
    for (int i=1;i<=n;i++)
    {
        scanf ("%s",mp[i]+1),mp[i][n+1]=‘#‘;
    }
    for (int i=0;i<=n+1;i++)
    {
        for (int j=0;j<=n+1;j++)
        {
            printf ("%c",mp[i][j]);
        }
        printf ("\n");
    }
    return 0;
}