uva 10047(BFS)

这道题稍微有点烦，主要是确定状态，除了表示位置（x,y）之外。还要记录当前方向朝地板的颜色，最后我们还需要记录步骤数。在确立状态后就是编码了。

我写的代码有点冗长。献丑了。

代码如下：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#define LEN 100
#define INF 0x7fffffff

using namespace std;

char Map[LEN][LEN];
int n, m, cnt = 1, vis[LEN][LEN][10][10];
int xx[] = {-1, 0, 1, 0};   //初始向上(dir+1)%4右转(dir-1)%4左转
int yy[] = { 0, 1, 0,-1};
typedef struct {
    int x, y, dir, col, step;
}POINT;

int BFS()
{
    queue<POINT> q;
    memset(vis, 0, sizeof vis);
    for(int i=1; i<=n; i++){
        for(int j=1; j<=m; j++){
            if(Map[i][j] == 'S'){
                POINT vex;vex.x = i;vex.y = j;
                vex.step = 1;vex.col = 0;
                vex.dir = 0;
                vis[vex.x][vex.y][vex.dir][vex.col] = 1;
                q.push(vex);
                break;
            }
        }
    }
    while(!q.empty()){
        POINT vex = q.front();q.pop();
        if(Map[vex.x][vex.y] == 'T' && vex.col == 0) return vex.step-1;
        POINT newv;newv.x = vex.x;newv.y = vex.y;
        newv.step = vex.step+1;newv.col = vex.col;
        newv.dir = (vex.dir+1)%4;
        if(vis[newv.x][newv.y][newv.dir][newv.col] == 0){
            vis[newv.x][newv.y][newv.dir][newv.col] = 1;
            q.push(newv);
        }
        newv.dir = (vex.dir-1+4)%4;
        if(vis[newv.x][newv.y][newv.dir][newv.col] == 0){
            vis[newv.x][newv.y][newv.dir][newv.col] = 1;
            q.push(newv);
        }
        newv.col = (vex.col+1)%5;newv.dir = vex.dir;
        newv.x = vex.x+xx[newv.dir];newv.y = vex.y+yy[newv.dir];
        if(newv.x>=1 && newv.x<=n && newv.y>=1 && newv.y<=m && Map[newv.x][newv.y] != '#' && vis[newv.x][newv.y][newv.dir][newv.col] == 0){
            vis[newv.x][newv.y][newv.dir][newv.col] = 1;
            q.push(newv);
        }
    }
    return -1;
}

int main()
{
//    freopen("in.txt", "r", stdin);

    while(scanf("%d%d", &n, &m)!=EOF)
    {
        memset(Map, 0, sizeof Map);
        if(n==0 && m==0)break;
        getchar();
        for(int i=1; i<=n; i++){
            for(int j=1; j<=m; j++){
                scanf("%c", &Map[i][j]);

            }
            getchar();
        }
        int ans = BFS();
        if(cnt!=1)printf("
");
        printf("Case #%d
", cnt++);
        if(ans == -1)printf("destination not reachable
");
        else printf("minimum time = %d sec
", ans);
    }
    return 0;
}