hdu2717 Catch That Cow

 1 #include<stdio.h>
 2 #include<math.h>
 3 #include<string.h>
 4 #include<stdlib.h>
 5 #include<iostream>
 6 #include<queue>
 7 using namespace std;
 8 struct stu{
 9     int x;
10     int t;
11 }abc,q;
12 int n,k;
13 int vis[100005];
14 void bfs()
15 {
16     queue<struct stu>p;
17     p.push(abc);
18     while(!p.empty())
19     {
20         abc=p.front();
21         p.pop();
22         if(abc.x==k)
23         {
24             printf("%d\n",abc.t);
25             return ;
26         }
27         q.x=abc.x-1;
28         if(q.x>=0&&q.x<=100000&&!vis[q.x])
29         {
30             q.t=abc.t+1;
31             vis[q.x]=1;
32             p.push(q);
33         }
34         q.x=abc.x+1;
35         if(q.x>=0&&q.x<=100000&&!vis[q.x])
36         {
37             q.t=abc.t+1;
38             vis[q.x]=1;
39             p.push(q);
40         }
41         q.x=abc.x*2;
42         if(q.x>=0&&q.x<=100000&&!vis[q.x])
43         {
44             q.t=abc.t+1;
45             vis[q.x]=1;
46             p.push(q);
47         }
48     }
49 }
50 
51 int main()
52 {
53     //freopen("in.txt","r",stdin);
54     while(~scanf("%d%d",&n,&k))
55     {
56         memset(vis,0,sizeof(vis));
57         abc.x=n;
58         abc.t=0;
59         vis[n]=1;
60         bfs();
61     }
62     return 0;
63 }