题目描述
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?
看不懂吗翻译
大意如下
农夫想要抓住一头牛 他站在一个地方 牛在一个地方,农夫可以消耗一点体力从当前坐标$X$走到$X+1$,$X-1$或者$X*2$的地方
请问最少多少体力能够抓到牛
Input
Line 1: Two space-separated integers: N and K
Output
Line 1: The least amount of time, in minutes, it takes for Farmer John to catch the fugitive cow.
Sample Input
5 17
Sample Output
4
解题思路
使用广度优先搜索,将当前的位置X所能到达的地方的坐标放入队列,并将当前的坐标从队列中删除,知道队列为空,典型的BFS
代码如下
1 |
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完事儿~