leetcode 328 Odd Even Linked List C++

这道题把奇数的拿出来，再把偶数的拿出来，连接上即可。

ListNode* oddEvenList(ListNode* head) {
if (!head) return head;

ListNode *odd = head;
ListNode *even = head -> next;
ListNode *evenHead = even;

while (even && even -> next) {
odd -> next = odd -> next -> next;
even -> next = even -> next -> next;
odd = odd -> next;
even = even -> next;
}
odd -> next = evenHead;
return head;
}