HDU 1242 Rescue(BFS+优先队列)

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<queue>
 4 #include<algorithm>
 5 using namespace std;
 6 
 7 struct node{
 8     int x,y,s;
 9     bool operator < (const node &a) const {
10     return a.s<s;};
11 };
12 bool bk[210][210]; 
13 char map[210][210];
14 void bfs(int sx,int sy);
15 int n,m,ex,ey;
16 
17 int main()
18 {
19     //freopen("E:\\testin.txt","r",stdin);
20     int sx,sy;
21     while(scanf("%d%d",&n,&m) != EOF){
22         memset(map,0,sizeof(map));
23         
24         for(int i=1;i<=n;i++){
25             for(int j=1;j<=m;j++){
26                 scanf(" %c",&map[i][j]);
27                 if(map[i][j] == ‘r‘)
28                 {
29                     sx=i;sy=j;
30                 }
31             }
32         }
33         
34         bfs(sx,sy);
35     }
36     return 0;
37 }
38 
39 void bfs(int sx,int sy){
40     priority_queue<struct node> q;
41     struct node head,temp,temp1;
42     memset(bk,0,sizeof(bk));
43     head.x=sx;
44     head.y=sy;
45     head.s=0;
46     int next[4][2]={-1,0,0,1,1,0,0,-1};
47     q.push(head);
48     bk[sx][sy]=1;
49     int flag=0,tx,ty;
50     
51     while(!q.empty()){
52         temp=q.top();q.pop();
53         
54         for(int i=0;i<4;i++){
55             tx=temp.x+next[i][0];
56             ty=temp.y+next[i][1];
57             
58             if(tx < 1 || tx > n || ty < 1 || ty > m || map[tx][ty] == ‘#‘ || map[tx][ty] == ‘r‘)
59                 continue;
60             if(bk[tx][ty] == 0){
61                 bk[tx][ty] = 1;
62                 
63                 if(map[tx][ty] == ‘.‘){
64                     temp1.x=tx;
65                     temp1.y=ty;
66                     temp1.s=temp.s+1;
67                     q.push(temp1);
68                 }
69                 if(map[tx][ty] == ‘x‘){
70                     temp1.x=tx;
71                     temp1.y=ty;
72                     temp1.s=temp.s+2;
73                     q.push(temp1);
74                 }
75                 if(map[tx][ty] == ‘a‘){
76                     flag=1;
77                     printf("%d\n",temp.s+1);
78                 }
79             }
80         }
81     }
82     if(flag == 0)
83         printf("Poor ANGEL has to stay in the prison all his life.\n");
84 }