POJ 1573 Robot Motion 模拟 难度:0

#define ONLINE_JUDGE
#include<cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

int A,B,sx,sy;
char maz[101][101];
int vis[101][101];
const int dx[4]={0,1,0,-1};
const int dy[4]={-1,0,1,0};

int dir(char ch){
if(ch=='N')return 0;
else if(ch=='E')return 1;
else if(ch=='S')return 2;
return 3;
}
void print(int step){
for(int s=1;s<step;s++){
for(int i=0;i<A;i++){
for(int j=0;j<B;j++){
if(vis[j][i]==s){
printf("vis[%d][%d]:%d\n",j,i,vis[j][i]);
}
}
}
}
}
void solve(){
memset(vis,0,sizeof(vis));
sx--;sy=0;
int step=0;
int fx,fy;
while(!vis[sy][sx]&&sx>=0&&sx<A&&sy>=0&&sy<B&&++step){
fx=sx;fy=sy;
vis[sy][sx]=step;
sx=dx[dir(maz[fy][fx])]+fx;
sy=dy[dir(maz[fy][fx])]+fy;
}
if(sx<0||sy<0||sx>=A||sy>=B)printf("%d step(s) to exit\n",step);
else {
printf("%d step(s) before a loop of %d step(s)\n",vis[sy][sx]-1,step+1-vis[sy][sx]);
}
}
int main(){
#ifndef ONLINE_JUDGE
freopen("output.txt","w",stdout);
#endif // ONLINE_JUDGE
while(scanf("%d%d%d",&B,&A,&sx)==3&&A&&B){

for(int i=0;i<B;i++)scanf("%s",maz[i]);
solve();
}
return 0;
}