Sort List

Sort List

Sort a linked list in O(n log n) time using constant space complexity.

Java代码：

/** * Definition for singly-linked list. * class ListNode { *     int val; *     ListNode next; *     ListNode(int x) { *         val = x; *         next = null; *     } * } */public class Solution {    public ListNode sortList(ListNode head) {        ListNode tmp = head;int len = 0;while (null != tmp) {len++;tmp = tmp.next;}int[] array = new int[len];tmp = head;for (int i = 0; i < len; i++) {array[i] = tmp.val;tmp = tmp.next;}Arrays.sort(array);    tmp =head;for (int i = 0; i < len; i++) {tmp.val = array[i];tmp = tmp.next;}return head;    }}