問題描述

public class Node { public int value; public Node next; public Node(int data) {this.value = data; } public Node reverse(Node head) {Node pre = null;Node next = null;while (head != null) { next = head.next; head.next = pre; pre = head; head = next;}return pre; }

這段代碼while循環中他是如何翻轉的?想要詳細一點的,debug了幾次還是沒弄懂具體是怎么回事

問題解答

參考一下，理解目的就比較好理解了。容易混亂的地方就是從右往左來處理，因為得先把后面的東西存起來，不然被覆蓋掉就丟了。

prehead +----+ +----+ +> +----+| | | | | | || | | | | | || | | | | | |+----+ +----+ | +----+| | | | | | || | | | | | |+----+ +-+--+ | +----+ | | +-----+ prehead nextnext = head.next;+----+ +----+ +> +----+| | | | | | || | | | | | || | | | | | |+----+ +----+ | +----+| | | | | | || | | | | | |+----+ +-+--+ | +----+ | | +-----+ prehead next+----+ <+ +----+ +----+| | | | | | || | | | | | || | | | | | |+----+ | +----+ +----+| | | | | | || | | | | | |+----+ | +-+--+ +----+| | head.next = pre;+----+ next preheadpre = head;+----+ <+ +----+ +----+ head = next;| | | | | | || | | | | | || | | | | | |+----+ | +----+ +----+| | | | | | || | | | | | |+----+ | +-+--+ +----+| |+----+回答2：

Ps:建議先多了解一下鏈表