[leetcode-328]Odd Even Linked List

此题非常巧妙的一个写法

ListNode* oddEvenList(ListNode* head) {    if (head == nullptr || head->next == nullptr) {        return head;    }    ListNode *odd = head, *even = head->next, *evenHead = even;    while (odd->next != nullptr && even->next != nullptr) {        odd->next = even->next;        odd = odd->next;        even->next = odd->next;        even = even->next;    }    odd->next = evenHead;    return head;}