> 
>exit写成exeit了，居然让我找了3个小时



 
> 
> #include<stdio.h>
> int main()
> {
>   int b[100][2],row,col,sta,i,x,y,count,flag=1;
>   char grid[10][12];
>   while(scanf("%d%d%d",&row,&col,&sta))
>   {
>     if(row==0&&col==0&&sta==0) break;
> 	  x=sta-1;  y=0; count=0;
> 	for(i=0;i<row;i++)
> 	  scanf("%s",grid[i]);
>      b[count][0]=x;b[count][1]=y; 
> 	 flag=1;
> 	while(flag)
> 	{   
> 	      count++;
> 	   switch(grid[y][x])
> 	   {
> 	    case'E':x=x+1;b[count][0]=x;b[count][1]=y;break;
> 	    case'W':x=x-1;b[count][0]=x;b[count][1]=y;break;
> 	    case'S':y=y+1;b[count][0]=x;b[count][1]=y;break;
> 	    case'N':y=y-1;b[count][0]=x;b[count][1]=y;break;
> 		
> 	   }
> 
> 	   for(i=0;i<count;i++) 
> 	   {
> 	       if(b[count][0]==b[i][0]&&b[count][1]==b[i][1])
> 		   {  
> 		      printf("%d step(s) before a loop of %d step(s)\n",i,count-i);
> 			  flag=0;
> 			  break;
> 		   }
> 		   
> 	   }
> 	  
> 	  if(x<0||x>=col||y<0||y>=row)
> 	  { 
> 	   
> 	   printf("%d step(s) to exeit\n",count);
> 		  flag=0;
> 	   
> 	  }
> 	}
>   }
>   return 0;
> }