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;
}
}