Insertion Sort List

这题一开始想新建一个list，结果MLE了，后来想了想不用新建，insertion的概念理解好就行，具体编程部分不难

 1 /**
 2  * Definition for singly-linked list.
 3  * struct ListNode {
 4  *     int val;
 5  *     ListNode *next;
 6  *     ListNode(int x) : val(x), next(NULL) {}
 7  * };
 8  */
 9 class Solution {
10 public:
11     ListNode *insertionSortList(ListNode *head) {
12         if (!head) return NULL;
13         ListNode *hpre = new ListNode(0);
14         hpre->next = head;
15         ListNode *pre = head;
16         head = head->next;
17         while (head) {
18             if (head->val > pre->val) {
19                 head = head->next;
20                 pre = pre->next;
21             }
22             else {
23                 pre->next = head->next;
24                 ListNode *tmp = hpre;
25                 while (head->val > tmp->next->val) tmp = tmp->next;
26                 head->next = tmp->next;
27                 tmp->next = head;
28                 head = pre->next;
29             }
30         }
31         return hpre->next;
32     }
33 };

 1 /**
 2  * Definition for singly-linked list.
 3  * public class ListNode {
 4  *     public int val;
 5  *     public ListNode next;
 6  *     public ListNode(int x) { val = x; }
 7  * }
 8  */
 9 public class Solution {
10     public ListNode InsertionSortList(ListNode head) {
11         if (head == null) return null;
12         ListNode hpre = new ListNode(0);
13         hpre.next = head;
14         ListNode pre = head;
15         head = head.next;
16         while (head != null) {
17             if (head.val > pre.val) {
18                 head = head.next;
19                 pre = pre.next;
20             }
21             else {
22                 pre.next = head.next;
23                 ListNode tmp = hpre;
24                 while (head.val > tmp.next.val) tmp = tmp.next;
25                 head.next = tmp.next;
26                 tmp.next = head;
27                 head = pre.next;
28             }
29         }
30         return hpre.next;
31     }
32 }

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posted @ 2014-01-08 11:20 ying_vincent 阅读(143) 评论(0) 收藏举报

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