HDOJ 2717 Catch That Cow

http://acm.hdu.edu.cn/showproblem.php?pid=2717

基本BFS

 

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <stdlib.h>
 4 #include <queue>
 5 using namespace std;
 6 int N,K;
 7 int degree[100002];
 8 queue<int> Q;
 9 void bfs()
10 {
11     while(!Q.empty()){
12         int cur=Q.front();
13         Q.pop();
14         if(cur==K)
15             break;
16         if(cur-1>=0&&degree[cur-1]==0){
17             degree[cur-1]=degree[cur]+1;
18             Q.push(cur-1);
19         }
20         if(cur+1<=100000&&degree[cur+1]==0){
21             degree[cur+1]=degree[cur]+1;
22             Q.push(cur+1);
23         }
24         if(cur*2<=100000&&degree[2*cur]==0){
25             degree[2*cur]=degree[cur]+1;
26             Q.push(2*cur);
27         }
28     }
29 }
30 
31 
32 int main()
33 {
34     while(scanf("%d%d",&N,&K)!=EOF){
35         int i;
36         for(i=0;i<100002;i++){
37             degree[i]=0;
38         }
39         while(!Q.empty())
40             Q.pop();
41 
42         Q.push(N);
43         bfs();
44         printf("%d\n",degree[K]);
45     }
46 }



posted @ 2011-11-29 19:57  linyvxiang  阅读(160)  评论(0)  编辑  收藏  举报