Robot Motion--POJ 1573

1、题目类型：模拟。

2、解题思路：水题，模拟robotd的移动，并记录移动步数即可。

3、注意事项：在loop时候，注意结束条件。

4、实现方法:

#include<iostream>
using namespace std;

struct Node{
    int step;
    char dir;
};

Node map[15][15];
int s,row,col,ans,t;
bool flag;

void solution()
{
    int i=1,j=s,p,q;
    map[i][j].step=1;
    while(i>0 &&i<=row &&j>0 &&j<=col)
    {
        p=i;
        q=j;
        switch(map[i][j].dir)
        {
        case 'E':    
            j++;
            if(!map[i][j].step)
            {
                map[i][j].step=map[p][q].step+1;
            }
            else
            {
                flag=0;
                ans=map[i][j].step-1;
                t=map[p][q].step-map[i][j].step+1;
                return;
            }
            break;
        case 'N':
            i--;
            if(!map[i][j].step)
            {
                map[i][j].step=map[p][q].step+1;
            }
            else
            {
                flag=0;
                ans=map[i][j].step-1;
                t=map[p][q].step-map[i][j].step+1;
                return;
            }
            break;
        case 'W':
            j--;
            if(!map[i][j].step)
            {
                map[i][j].step=map[p][q].step+1;
            }
            else
            {
                flag=0;
                ans=map[i][j].step-1;
                t=map[p][q].step-map[i][j].step+1;
                return;
            }
            break;
        case 'S':
            i++;
            if(!map[i][j].step)
            {
                map[i][j].step=map[p][q].step+1;
            }
            else
            {
                flag=0;
                ans=map[i][j].step-1;
                t=map[p][q].step-map[i][j].step+1;
                return;
            }
            break;
        default:
            break;
        }
    }
    ans=map[p][q].step;
}

int main()
{
    int i,j;
    while(cin>>row>>col>>s && row || col || s)
    {
        flag=1;
        ans=0;
        memset(map,0,sizeof(map));
        
        for(i=1;i<=row;i++)
        {
            getchar();
            for(j=1;j<=col;j++)
            {
                scanf("%c",&map[i][j].dir);
            }
        }
        solution();
        if(flag)
            cout<<ans<<" step(s) to exit"<<endl;
        else
            cout<<ans<<" step(s) before a loop of "<<t<<" step(s)"<<endl;
    }
    return 0;
}