Catch That Cow

View Code 
 1 //zzuli1220
 2 #include<stdio.h>
 3 #include<queue>
 4 using namespace std;
 5 int n,k;
 6 int f[100001];
 7 bool a[100001];
 8 queue<int>q;
 9 void bfs()
10 {
11     int x;
12     a[n]=1;
13     q.push(n);
14     while(!q.empty())
15     {
16         x=q.front();
17         q.pop();
18         if(x==k)
19             break;
20 
21         if(x-1>=0&&!a[x-1])
22         {
23             a[x-1]=1;
24             q.push(x-1);
25             f[x-1]=f[x]+1;
26         }
27         if(x+1<=100000&&!a[x+1])
28         {
29             a[x+1]=1;
30             q.push(x+1);
31             f[x+1]=f[x]+1;
32         }
33         if(x*2<=100000&&!a[x*2])
34         {
35             a[x*2]=1;
36             q.push(x*2);
37             f[x*2]=f[x]+1;
38         }
39     }
40 
41 }
42 int main()
43 {
44     scanf("%d%d",&n,&k);
45     bfs();
46     printf("%d\n",f[k]);
47     return 0;
48 }

 

posted @ 2012-07-19 17:24  zlyblog  阅读(213)  评论(0)    收藏  举报