【bzoj2241】 SDOI2011打地鼠 暴力+剪枝

#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<iostream>
#include<algorithm>
#define maxn 110
#define inf 1000000000

using namespace std;

int a[maxn][maxn],b[maxn][maxn];
int sum,n,m,ans;

bool check(int x,int y)
{
	for (int i=1;i<=n;i++)
	  for (int j=1;j<=m;j++)
	    b[i][j]=a[i][j];
	for (int i=1;i<=n;i++)
	  for (int j=1;j<=m;j++)
	  {
	  	int num=b[i][j];
	  	if (num && i+x-1<=n && j+y-1<=m)
	  	{
	  		for (int xx=i;xx<=i+x-1;xx++)
	  		  for (int yy=j;yy<=j+y-1;yy++)
	  		  {
	  		  	b[xx][yy]-=num;
	  		  	if (b[xx][yy]<0) return 0;
	  		  }
	  	}
	  	if (b[i][j]) return 0;
	  }
	return 1;
}

int main()
{
	scanf("%d%d",&n,&m);
	for (int i=1;i<=n;i++)
	  for (int j=1;j<=m;j++)
	  {
	  	scanf("%d",&a[i][j]);
	  	sum+=a[i][j];
	  }
	ans=inf;
	for (int i=n;i>=1;i--)
	  for (int j=m;j>=1;j--)
	    if (sum%(i*j)==0 && sum/(i*j)<ans && check(i,j)) ans=sum/(i*j); 
	printf("%d\n",ans);
	return 0;
}