【HDOJ】1242 Rescue

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <queue>
 5 using namespace std;
 6 
 7 #define MAXNUM 205
 8 
 9 typedef struct node_st {
10     int x, y ,t;
11     node_st() {}
12     node_st(int xx, int yy, int tt) {
13         x = xx; y = yy; t = tt;
14     }
15     friend bool operator < (node_st a, node_st b) {
16         return a.t > b.t;
17     }
18 } node_st;
19 
20 int n, m;
21 char map[MAXNUM][MAXNUM];
22 char visit[MAXNUM][MAXNUM];
23 int direct[4][2] = {{1,0},{-1,0},{0,-1},{0,1}};
24 
25 int bfs(int x, int y) {
26     priority_queue<node_st> que;
27     node_st node;
28     int i, t;
29     
30     que.push(node_st(x, y, 0));
31     memset(visit, 0, sizeof(visit));
32     visit[x][y] = 1;
33     
34     while ( !que.empty() ) {
35         node = que.top();
36         if (map[node.x][node.y] == ‘a‘)
37             return node.t;
38         que.pop();
39         t = node.t + 1;
40         for (i=0; i<4; ++i) {
41             x = node.x + direct[i][0];
42             y = node.y + direct[i][1];
43             if (x<0 || x>=n || y<0 || y>=m)
44                 continue;
45             if (visit[x][y] || map[x][y]==‘#‘)
46                 continue;
47             if (map[x][y] == ‘x‘)
48                 que.push(node_st(x,y,t+1));
49             else
50                 que.push(node_st(x,y,t));
51             visit[x][y] = 1;
52         }
53     }
54 
55     return -1;
56 }
57 
58 int main() {
59     int i, j, t;
60     int begx, begy;
61 
62     while (scanf("%d %d", &n, &m) != EOF) {
63         for (i=0; i<n; ++i) {
64             scanf("%s", map[i]);
65             for (j=0; j<m; ++j) {
66                 if (map[i][j] == ‘r‘) {
67                     begx = i;
68                     begy = j;
69                 }
70             }
71         }
72         t = bfs(begx, begy);
73         if (t == -1)
74             printf("Poor ANGEL has to stay in the prison all his life.\n");
75         else
76             printf("%d\n", t);
77     }
78     return 0;
79 }