1 /**
2 * Definition of ListNode
3 * class ListNode {
4 * public:
5 * int val;
6 * ListNode *next;
7 * ListNode(int val) {
8 * this->val = val;
9 * this->next = NULL;
10 * }
11 * }
12 */
13 class Solution {
14 public:
15 /**
16 * @param head: The first node of linked list.
17 * @return: The head of linked list.
18 */
19 ListNode *insertionSortList(ListNode *head) {
20 // write your code here
21 ListNode* new_head = new ListNode(0);
22 new_head -> next = head;
23 ListNode* pre = new_head;
24 ListNode* cur = head;
25 while (cur) {
26 if (cur -> next && cur -> next -> val < cur -> val) {
27 while (pre -> next && pre -> next -> val < cur -> next -> val)
28 pre = pre -> next;
29 /* Insert cur -> next after pre. */
30 ListNode* temp = pre -> next;
31 pre -> next = cur -> next;
32 cur -> next = cur -> next -> next;
33 pre -> next -> next = temp;
34 /* Move pre back to the starting node. */
35 pre = new_head;
36 }
37 else cur = cur -> next;
38 }
39 ListNode* res = new_head -> next;
40 delete new_head;
41 return res;
42 }
43 };
