leetcode 134 奇偶链表 Odd Even Linked List

 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* oddEvenList(ListNode* head) {
12         if(head==NULL||head->next==NULL) return head;
13         ListNode* cur;
14         ListNode* nex;
15         ListNode* head2;
16         cur=head;nex=head->next;head2=nex;
17         int flag=1;
18         while(nex->next!=NULL){
19             cur->next=nex->next;
20             cur=nex;nex=nex->next;
21             flag=-flag;
22         }
23         cur->next=NULL;
24         
25         if(flag==1){
26             cur->next=head2;
27         }else{
28             nex->next=head2;
29         }
30         return head;
31     }
32 };