多校 Robot Motion

题目链接：http://acm.hust.edu.cn/vjudge/contest/124435#problem/J

密码：acm

Sample Input
 
NEESWE
WWWESS
SNWWWW
 
SESWE
EESNW
NWEEN
EWSEN
 
Sample Output
 step(s) to exit
 step(s) before a loop of  step(s)

分析：

 #include <iostream>
 #include <stdio.h>
 #include <string.h>
 #include <algorithm>
 #include <stdlib.h>
 #include<queue>
 #include<math.h>
 using namespace std;
 
 #define N 1001
 char s[N][N];
 int a[N][N],b[N][N];
 
 int main()
 {
     int n,m,c,ans;
     while(scanf("%d%d%d",&n,&m,&c),n+m+c)
     {
         memset(a,,sizeof(a));
         memset(b,,sizeof(b));
         ans=;
 
         for(int i=;i<=n;i++)
             scanf("%s",s[i]);
 
        int i=;
        int j=c-;///字符串里面从零开始记录的，老是忘~~~~(>_<)~~~~
         while(1)
         {
             b[i][j]=;
             if(s[i][j]=='N')
                 i=i-;
             else if(s[i][j]=='S')
                 i=i+;
             else if(s[i][j]=='E')
                 j=j+;
             else
                 j=j-;
             ans++;
             if(b[i][j])
             {
                 printf("%d step(s) before a loop of %d step(s)\n",a[i][j],ans-a[i][j]);
                 break;
             }
             a[i][j]=ans;
 
             if(i==||j==-||i==n+||j==m)
             {
                 printf("%d step(s) to exit\n",ans);
                 break;
             }
         }
     }
     return ;
 }