为什么会RE

#include<bits/stdc++.h>
using namespace std;
int a[1005][1005];
int b[100000000];
int main(){
    int t;
    cin>>t;
    int x,y,d;
    int n,m,k;
    for(int i=0;i<t;i++){
        a[1005][1005]=0;
        cin>>n>>m>>k;
        cin>>x>>y>>d;
        x-=1;
        y-=1;
        char s;
        int sum=1;
        for(int j=0;j<n;j++){
            for(int b=0;b<m;b++){
                cin>>s;
                if(s=='.'){
                    a[j][b]=1;
                }
            }
        }
        while(k>0){
            if(d==0){
                if(y+1<m&&a[x][y+1]>0){
                    if(a[x][y+1]==1){
                        sum+=1;
                    }
                    a[x][y+1]+=1;
                    y+=1;
                }
                else 
                    d=(d+1)%4;
                k-=1;
            }
            else if(d==1){
                if(x+1<n&&a[x+1][y]>0){
                    if(a[x+1][y]==1){
                        sum+=1;
                    }   
                    a[x+1][y]+=1;
                    x+=1;
                }
                else 
                    d=(d+1)%4;
                k-=1;
            }
            else if(d==2){
                if(y-1>=0&&a[x][y-1]>0){
                    if(a[x][y-1]==1){
                        sum+=1;
                    }   
                    a[x][y-1]+=1;
                    y-=1;
                }
                else 
                    d=(d+1)%4;
                k-=1;
            }
            else if(d==3){
                if(x-1>=0&&a[x-1][y]>0){
                    if(a[x-1][y]==1){
                        sum+=1;
                    }   
                    a[x-1][y]+=1;
                    x-=1;
                }
                else 
                    d=(d+1)%4;
                k-=1;
            }
        }
        b[i]=sum;
    }
    for(int j=0;j<t;j++){
            cout<<b[j]<<endl;
        }
    return 0;
}