Odd Even Linked List(JS实现)

该开始以为space O(1)是只能定义一个变量，后来百度才知道是就地逆置；

 网上看到这个方法，感觉很巧妙，自己用js写的；

var oddEvenList = function(head) {
    if(head===null||head.next===null) return head;
    var odd = head;
    var even = head.next;
    var even_head = even;
//奇数结尾even==null,偶数结尾even.next==null
   while(even!==null && even.next!==null){
      odd.next = even.next;
      odd = odd.next;
      even.next = odd.next;
      even = even.next;
    }
     odd.next = even_head;
     return head;
};