P2484 [SDOI2011]打地鼠

差分

代码：

#include <bits/stdc++.h>
using namespace std;
#define INF 1999999999
int n,m,sum,a[200][200],b[200][200],c[200][200];
int main(){
    int minn=INF;
  cin>>n>>m;
  for (int i=1;i<=n;i++)
    for (int j=1;j<=m;j++)
      cin>>a[i][j],sum+=a[i][j];
  for (int i=1;i<=n;i++)
      for (int j=1;j<=m;j++)
        if (sum%(i*j)==0)
           {
               memset(b,0,sizeof(b)); memset(c,0,sizeof(c)); 
                int num=0;
               for (int i1=1;i1<=n;i1++)
                 for (int j1=1;j1<=m;j1++)
                 {
                     c[i1][j1]=c[i1-1][j1]+c[i1][j1-1]-c[i1-1][j1-1]+b[i1][j1];
                      if (a[i1][j1]<c[i1][j1])
                      {
                          goto ll;
                      } else
                      if (a[i1][j1]==c[i1][j1])
                      {
                          continue;
                      }
              {
                  if (i+i1-1>n || j+j1-1>m)
                  {
                      goto ll;
                  }
                  int tmp=a[i1][j1]-c[i1][j1];
                  b[i1+i][j1]-=tmp;
                  b[i1][j1+j]-=tmp;
                  b[i1+i][j1+j]+=tmp;
                  c[i1][j1]+=tmp;
                  num+=tmp;
                      }
                  }
                minn=min(minn,num);
                ll:;
        }
    cout<<minn;
}