將二維陣列優化為一維陣列的DP可以加快速度！！！糾結中

AC：

#include<cstdlib>
#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
#include<set>
#include<map>
#include<list>
#include<queue>
#include<vector>
#define LL long long
#define inf 0x7fffffff
#define E 1e-9
#define M 100
#define N 2001
using namespace std;
int m,n;
char str[N][N];
int up[N];
int fun(int x,int y)
{
    int cnt=0;
        for(int j=0; j<m; ++j)
        {
            if(up[j]>=x)
                {
                    int num=1;j++;
                    while(j<m&&up[j]>=x)num++,j++;
                    if(num>=y)cnt+=num-y+1;
                }
        }
    return cnt;
}
int main()
{
#ifndef ONLINE_JUDGE
    freopen("ex.in","r",stdin);
#endif
    while(scanf("%d%d",&n,&m)==2&&(n||m))
    {

        int x,y;
        scanf("%d%d",&x,&y);
        for (int i=0; i<n; ++i )
            scanf("%s",str[i]);

        memset(up,0,sizeof(up));
        int cnt=0;
        for (int i=0; i<n; ++i )
        {
            for(int j=0; j<m; ++j)
                if(str[i][j]=='*')
                    up[j]++;
                else
                    up[j]=0;
            cnt+=fun(x,y);
            if(x!=y)
                cnt+=fun(y,x);
        }

        printf("%d\n",cnt);
    }
    return 0;
}
 

#include<cstdlib>
#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
#include<set>
#include<map>
#include<list>
#include<queue>
#include<vector>
#define LL long long
#define inf 0x7fffffff
#define E 1e-9
#define M 100
#define N 2001
using namespace std;
int m,n;
char str[N][N];
int c[N][N],up[N][N];
int fun(int x,int y)
{
    memset(c,0,sizeof(c));
    int cnt=0;
    for(int i=x-1; i<n; i++)
        for(int j=0; j<m; ++j)
        {
            if(up[i][j]>=x)
                c[i][j]=(j==0)?1:c[i][j-1]+1;
            else
                c[i][j]=0;
            if(c[i][j]>=y)cnt++;
        }
    return cnt;
}
int main()
{
#ifndef ONLINE_JUDGE
    freopen("ex.in","r",stdin);
#endif
    while(scanf("%d%d",&n,&m)==2&&(n||m))
    {

        int x,y;
        scanf("%d%d",&x,&y);
        for (int i=0; i<n; ++i )
            scanf("%s",str[i]);

        memset(up,0,sizeof(up));
        for(int j=0; j<m; ++j)
            for (int i=0; i<n; ++i )
                if(str[i][j]=='*')
                    up[i][j]=(i==0)?1:up[i-1][j]+1;
                else
                    up[i][j]=0;

        int cnt=fun(x,y);
        if(x!=y)
        cnt+=fun(y,x);

        printf("%d\n",cnt);
    }
    return 0;
}