深搜迷宫

#include<stdio.h>
int vis[22][22]={0};
//char c[5][5]={{'*','*','*','*','#'},{'*','*','#','*','#'},{'#','*','#','*','#'},{'#','*','*','*','*'},{'*','*','#','*','#'}};
//char c[5][5]={{'*','#','*','*','#'},{'#','#','#','*','#'},{'#','*','#','*','#'},{'#','*','*','*','*'},{'*','*','#','*','#'}};
char  c[22][22];
int w,h;   
int dw,dh;
int sw,sh;
int dfs(int x,int y)
{  
    if(x==dw && y==dh) return 1;
    for(int i=0;i<4;++i)
    {
        if(i==0)
        {
            if(c[x][y+1]!='#' && y+1<=h && vis[x][y+1]!=1)
            {
                vis[x][y]=1;
                if(dfs(x,y+1)) return 1;
                vis[x][y]=0;
            }
        }
        if(i==1)
        {
            if(c[x+1][y]!='#' && x+1<=w && vis[x+1][y]!=1)
            {
                vis[x][y]=1;
                if(dfs(x+1,y)) return 1;
                vis[x][y]=0;
            }
        }
        if(i==2)
        {
            if(c[x][y-1]!='#' && y-1>=0 && vis[x][y-1]!=1)
            {
                vis[x][y]=1;
                if(dfs(x,y-1)) return 1;
                vis[x][y]=0;
            }
        }
        if(i==3)
        {
            if(c[x-1][y]!='#' && x-1>=0 && vis[x-1][y]!=1)
            {
                vis[x][y]=1;
                if(dfs(x-1,y)) return 1;
                vis[x][y]=0;
            }
        }
    }
    return 0;
}
int main()
{
    scanf("%d%d",&w,&h);
    scanf("%d%d",&sw,&sh);
    scanf("%d%d",&dw,&dh);
    for(int i=0;i<w;++i)
        for(int j=0;j<h;++j)
            scanf("%c",&c[i][j]);
    getchar();
    if(dfs(sw,sh)) printf("YES\n");
    else printf("NO\n");
    return 0;
}