Catch That Cow-抓住那头牛（BFS+队列） Catch That Cow HDU - 2717
Catch That CowHDU - 2717Farmer 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 li.
