Leetcode 328. 奇偶链表 （将节点编号为奇数和偶数的链表分别排在一起）

我写的代码

class Solution {
public:
    ListNode* oddEvenList(ListNode* head) {
        if(head==NULL) return head;
        ListNode* evenHead = new ListNode(-1);
        ListNode* evenTail = evenHead;
        ListNode* p = head;
        while(p&&p->next){
            ListNode* q = p->next;
            evenTail->next = q;
            evenTail = evenTail->next;
            p->next = q->next;
            q->next = NULL;
            if(p->next!=NULL) p = p->next;
            else break;
        }
        p->next = evenHead->next;
        return head;
    }
};

标准答案代码: 奇偶指针解耦移动，很漂亮。

class Solution {
public:
    ListNode* oddEvenList(ListNode* head) {
        if (head == NULL) return NULL;
        ListNode* odd = head, *even = head->next, *evenHead = even;
        while (even != NULL && even->next != NULL) {
            odd->next = even->next;
            odd = odd->next;
            even->next = odd->next;
            even = even->next;
        }
        odd->next = evenHead;
        return head;
    }
};