题解 | #14.链表的奇偶重排#

奇偶链表分别放，最后在合并

引入没用的结点充当头

注意：

1. 20行、21行的oddList.next = null ; evenList.next=null必须要写，因为他们的next不为空

function oddEvenList( head ) {
  if(head==null || head.next==null)
    return head;
  
  let oddList = {}, savedOddList = oddList;;//奇数链表
  let evenList = {}, savedEvenList = evenList;;//偶数链表
  
  let flag = true;//true表示奇数个
  while(head != null){
    if(flag){
      oddList.next = head;
      oddList = oddList.next;
    }else{
      evenList.next = head;
      evenList = evenList.next;
    }
    head = head.next;
    flag = !flag;
  }
  oddList.next = null;
  evenList.next = null;//!!!!
  
  oddList.next = savedEvenList.next;
  return savedOddList.next;
}
module.exports = {
    oddEvenList : oddEvenList
};