CF586D. Phillip and Trains

 /*
  CF586D. Phillip and Trains
  http://codeforces.com/problemset/problem/586/D
  搜索
  */
 #include<cstdio>
 #include<algorithm>
 #include<string.h>
 using namespace std;
 const int Nmax=;
 char map[][Nmax];
 int fail[][Nmax];
 int n,k;
 int t,ans;

 int dfs(int step,int pos)
 {
     if(step==n- && map[pos][step+]=='.')
     {
         ans=;
         return ;
     }
     if(step>=n)
     {
         ans=;
         return ;
     }
     if(ans)
         return ;
     if(fail[pos][step])
         return ;

     if(map[pos][step]>='A' && map[pos][step]<='Z')
     {
         fail[pos][step]=;
         return ;
     }
     for(int k=pos-;k<=pos+;k++)
     {
         if(k>= && k<= && map[pos][step+]=='.' &&map[k][step+]=='.' && !fail[k][step+] && !fail[k][step+] && !fail[k][step+])
         {
             if(map[k][step+]=='.' && map[k][step+]=='.')
             {
                 if(dfs(step+,k))
                 {
                     ans=;
                     return ;
                 }
                 else
                 {
                     fail[k][step+]=;
                 }
             }

         }
     }
     fail[pos][step]=;
     return ;
 }

 int main()
 {
     scanf("%d",&t);
     while(t--)
     {
         scanf("%d%d",&n,&k);
         for(int i=;i<=;i++)
             for(int j=;j<=n+;j++)
                 fail[i][j]=;
         getchar();
         gets(map[]+);
         gets(map[]+);
         gets(map[]+);
         for(int i=;i<=;i++)
             for(int j=n+;j<=n+;j++)
                 map[i][j]='.';
         ans=;
         int pos=,start;
         for(int i=;i<=;i++)
             if(map[i][]=='s')
                 pos=i;

         if(dfs(,pos))
             printf("YES\n");
         else
             printf("NO\n");
     }
     return ;
 }