2179. Catch That Cow

单点时限: 2.0 sec

内存限制: 256 MB

Farmer John has been informed of the location of a fugitive cow and wants to catch her immediately. He starts at a point N (0 <= N <= 100,000) on a number line and the cow is at a point K (0 <= K <= 100,000) on the same number line. Farmer John has two modes of transportation: walking and teleporting.

  • Walking: FJ can move from any point X to the points X-1 or X+1 in a single minute

  • Teleporting: FJ can move from any point X to the point 2*X in a single minute.

If the cow, unaware of its pursuit, does not move at all, how long does it take for Farmer John to retrieve it?

输入格式

  • Line 1: Two space-separated integers: N and K

输出格式

  • Line 1: The least amount of time, in minutes, it takes for Farmer John to catch the fugitive cow.

样例

Input
5 17
Output
4

39 人解决,59 人已尝试。

56 份提交通过,共有 170 份提交。

7.8 EMB 奖励。

创建: 12 年,7 月前.

修改: 2 年,3 月前.

最后提交: 5 月前.

来源: Elite 2007 US Open Competition

题目标签
bfs