hdu 4517

#include <string.h>#include <iostream>#include <stdio.h>using namespace std;char map[2002][2002];int cnt[2002][2002];//我的map下标从1,1开始//cnt保存从左上角(0,0)到(i,j) 的*的个数int n,m;int main(void){//freopen("","r",stdin);    while(scanf("%d %d",&n,&m),n&&m){int x,y;scanf("%d %d",&x,&y);getchar();for(int i = 1;i<=n;i++) gets(map[i]+1);//下标从1,1开始for(int i = 0;i<=n;i++) map[i][0] = 0;//0行列要清零for(int i = 0;i<=m;i++) map[0][i] = 0;//dp方程 画个图就懂了for(int i = 1;i<=n;i++)for(int j = 1;j<=m;j++)cnt[i][j] = cnt[i-1][j]+cnt[i][j-1]-cnt[i-1][j-1]+(map[i][j]=='*'?1:0);int ans = 0;//枚举每个点for(int i = 1;i<=n;i++)for(int j = 1;j<=m;j++){if(i+x-1<=n&&j+y-1<=m){int area = cnt[i+x-1][j+y-1]-cnt[i+x-1][j-1]-cnt[i-1][j+y-1]+cnt[i-1][j-1];if(area==x*y) ans++;}//横着if(x!=y&&i+y-1<=n&&j+x-1<=m){int area = cnt[i+y-1][j+x-1]-cnt[i+y-1][j-1]-cnt[i-1][j+x-1]+cnt[i-1][j-1];if(area==x*y) ans++;}//竖着}printf("%d\n",ans);}}