HDU 1035 Robot Motion

简单的搜索题：

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int flag,Count,step;
char map[15][15];
int STEP[15][15];
bool hash[15][15];
void  DFS( int x, int y, int cnt  )
{    
    
    if( hash[x][y] )
    {
//        flag =2;
           Count = cnt - STEP[x][y];
           step = STEP[x][y];
           return;
    }
       if( flag||map[x][y]==0 ) 
       {
       flag = 1;
       Count = cnt;    
       return;    
    }
    STEP[x][y] = cnt;
    hash[x][y] = 1;
    if( map[x][y]=='E' )
    {
       DFS( x , y +1 ,cnt+1 );     
    }
    else
    {
       if( map[x][y]=='S' )
       {
          DFS( x+1 , y  ,cnt+1 );          
       }
       else
       {
           if( map[x][y]=='W' )
           {
              DFS( x , y -1 ,cnt+1 );          
           }
           else
           {
              DFS( x-1 , y  ,cnt+1 );
            }    
       }    
    }
    return;
}
int main( )
{
    int n,m,start;
    while( scanf( "%d%d",&n,&m ),n||m )
    {
       flag = 0;
       memset( map , 0 ,sizeof( map ) );
       memset( STEP , 0 , sizeof( STEP ) );
       memset( hash , 0 , sizeof( hash )  );
       scanf( "%d",&start );
       for( int i = 1 ;i<= n ; i++ )
         scanf( "%s",map[i]+1 );
       DFS( 1 , start,0 );
       if( flag ) printf( "%d step(s) to exit\n",Count );
       else printf( "%d step(s) before a loop of %d step(s)\n",step, Count );
    }
    return 0;    
}