LeetCode-Insertion Sort List

记清insertion sort 的方法

然后就是dummy！！！

public class Solution {    public ListNode insertionSortList(ListNode head) {        if ( head == null || head.next == null )            return head;        ListNode temp = head;        ListNode dummy = new ListNode(0);        dummy.next = head;        while ( temp.next != null ){            ListNode cur = temp.next;            if ( temp.val > temp.next.val){                ListNode node = dummy.next;                ListNode pre = dummy;                while ( node.val <= cur.val ){                    node = node.next;                    pre = pre.next;                }                temp.next = cur.next;                cur.next = node;                pre.next = cur;            }            else                temp = temp.next;        }        return dummy.next;    }}