小小明系列故事——游戏的烦恼

#include <stdio.h>

char arr[2001][2001];
int dp[2001][2001];

void func(int m, int n, int x, int y)
{
int i, j, ii;
int target_num, count;

target_num = x*y;
count = 0;
for(i=0; i<=m; i++)
{
for(j=0; j<=n; j++)
{
if(i==0 || j== 0)
{
dp[i][j] = 0;
}
else
{
dp[i][j] = dp[i][j-1] + dp[i-1][j] - dp[i-1][j-1];
if(arr[i][j] == '*')
dp[i][j] ++;
}

if(i>=x && j>=y && arr[i][j]=='*')
{
if(dp[i][j] + dp[i-x][j-y] - dp[i-x][j] - dp[i][j-y] == target_num)
count ++;
}
if(x == y)
continue;

if(i>=y && j>=x && arr[i][j]=='*')
{
if(dp[i][j] + dp[i-y][j-x] - dp[i-y][j] - dp[i][j-x] == target_num)
count ++;
}
}
}

printf("%d\n", count);
}

int main(void)
{
int m, n;
int x, y;
int i;

//freopen("input.dat", "r", stdin);

while(1)
{
scanf("%d %d", &m, &n);
if(!m && !n)
break;

scanf("%d %d", &x, &y);
getchar();
for(i=1; i<=m; i++)
{
gets(arr[i]+1);
}

func(m, n, x, y);
}

return 0;
}