[kuangbin带你飞]专题一 简单搜索 - C - Catch That Cow

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<string>
 4 #include<vector>
 5 #include<queue>
 6 #include<cstring>
 7 using namespace std;
 8 int n, k, c, ans;
 9 int num[100005];
10 int main()
11 {
12 //    freopen("in.in","r",stdin);
13     while(cin>>n>>k)
14     {
15         ans = 0;
16         queue<int>q;
17         q.push(n);
18         num[n] = 1;
19         while(q.size())
20         {
21             c = q.front();
22             if(c == k)
23             {
24                 ans = num[c];
25                 break;
26             }    
27             q.pop();
28             if(!num[c-1] && c-1>=0)
29             {
30                 num[c-1] = num[c] + 1;
31                 q.push(c-1);
32             }
33             if(c+1<=100000 && !num[c+1])
34             {
35                 num[c+1] = num[c] + 1;
36                 q.push(c+1);
37             }
38             if(c*2<=100000 && !num[2*c])
39             {
40                 num[2*c] = num[c] + 1;
41                 q.push(2*c);
42             }
43         }
44         cout<<ans-1<<endl;
45     }
46     return 0;
47 }