usaco Home on the Range(dp+容斥原理）

/*
ID: modengd1
PROG: range
LANG: C++
*/
#include <iostream>
#include <stdio.h>
#include <memory.h>

using namespace std;
int sum[251][251];
int N;
int ans[251];
int main()
{
freopen("range.in","r",stdin);
freopen("range.out","w",stdout);
char ch;
scanf("%d",&N);
getchar();
memset(sum,0,sizeof(sum));
memset(ans,0,sizeof(ans));
for(int i=1;i<=N;i++)
{
for(int j=1;j<=N;j++)
{
scanf("%c",&ch);
sum[i][j]=sum[i-1][j]+sum[i][j-1]+(int)(ch-'0')-sum[i-1][j-1];
}
getchar();
}
for(int k=2;k<=N;k++)
{
for(int i=1;i<=N-k+1;i++)
{
for(int j=1;j<=N-k+1;j++)
{
int area1=sum[i+k-1][j+k-1];
int area2=sum[i+k-1][j-1];
int area3=sum[i-1][j+k-1];
int area4=sum[i-1][j-1];
int area5=area1-area2-area3+area4;
if(area5==k*k)
ans[k]++;
}
}
}
for(int i=2;i<=N;i++)
{
if(ans[i]!=0)
cout<<i<<' '<<ans[i]<<endl;
}
return 0;
}