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：

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <cmath>
 5 #include <cstdlib>
 6 #include <algorithm>
 7 #include <vector>
 8 #include <queue>
 9 #include <stack>
10 #define LEN 100
11 #define INF 0x7fffffff
12 
13 using namespace std;
14 
15 char Map[LEN][LEN];
16 int n, m, cnt = 1, vis[LEN][LEN][10][10];
17 int xx[] = {-1, 0, 1, 0};   //初始向上(dir+1)%4右转(dir-1)%4左转
18 int yy[] = { 0, 1, 0,-1};
19 typedef struct {
20     int x, y, dir, col, step;
21 }POINT;
22 
23 int BFS()
24 {
25     queue<POINT> q;
26     memset(vis, 0, sizeof vis);
27     for(int i=1; i<=n; i++){
28         for(int j=1; j<=m; j++){
29             if(Map[i][j] == 'S'){
30                 POINT vex;vex.x = i;vex.y = j;
31                 vex.step = 1;vex.col = 0;
32                 vex.dir = 0;
33                 vis[vex.x][vex.y][vex.dir][vex.col] = 1;
34                 q.push(vex);
35                 break;
36             }
37         }
38     }
39     while(!q.empty()){
40         POINT vex = q.front();q.pop();
41         if(Map[vex.x][vex.y] == 'T' && vex.col == 0) return vex.step-1;
42         POINT newv;newv.x = vex.x;newv.y = vex.y;
43         newv.step = vex.step+1;newv.col = vex.col;
44         newv.dir = (vex.dir+1)%4;
45         if(vis[newv.x][newv.y][newv.dir][newv.col] == 0){
46             vis[newv.x][newv.y][newv.dir][newv.col] = 1;
47             q.push(newv);
48         }
49         newv.dir = (vex.dir-1+4)%4;
50         if(vis[newv.x][newv.y][newv.dir][newv.col] == 0){
51             vis[newv.x][newv.y][newv.dir][newv.col] = 1;
52             q.push(newv);
53         }
54         newv.col = (vex.col+1)%5;newv.dir = vex.dir;
55         newv.x = vex.x+xx[newv.dir];newv.y = vex.y+yy[newv.dir];
56         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){
57             vis[newv.x][newv.y][newv.dir][newv.col] = 1;
58             q.push(newv);
59         }
60     }
61     return -1;
62 }
63 
64 int main()
65 {
66 //    freopen("in.txt", "r", stdin);
67 
68     while(scanf("%d%d", &n, &m)!=EOF)
69     {
70         memset(Map, 0, sizeof Map);
71         if(n==0 && m==0)break;
72         getchar();
73         for(int i=1; i<=n; i++){
74             for(int j=1; j<=m; j++){
75                 scanf("%c", &Map[i][j]);
76 
77             }
78             getchar();
79         }
80         int ans = BFS();
81         if(cnt!=1)printf("\n");
82         printf("Case #%d\n", cnt++);
83         if(ans == -1)printf("destination not reachable\n");
84         else printf("minimum time = %d sec\n", ans);
85     }
86     return 0;
87 }
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posted @ 2013-11-26 19:32  张小豪  阅读(271)  评论(0)  编辑  收藏  举报