LeetCode分隔链表

LeetCode分隔链表

题目链接地址

• 解题思路

  用双链表法

  链表一： 1->2->2

  链表二：4->3->5

• python代码

  
  # Definition for singly-linked list.
  
  
  # class ListNode(object):
  
  
  #     def __init__(self, x):
  
  
  #         self.val = x
  
  
  #         self.next = None
  
  
  class Solution(object):
    def partition(self, head, x):
        """
        :type head: ListNode
        :type x: int
        :rtype: ListNode
        """
        startOne, startTwo = None, None
        endOne, endTwo = None, None
  
        temp = head
  
        while temp != None:
            if temp.val < x:
                if endOne == None:
                    startOne = temp
                    endOne = temp
                else:
                    endOne.next = temp
                    endOne = temp
  
            else:
                if endTwo == None:
                    startTwo = temp
                    endTwo = temp
                else:
                    endTwo.next = temp
                    endTwo = temp
  
            temp = temp.next
  
        if endTwo != None:
            endTwo.next = None
  
        #防止链表一为空
        if endOne != None:
            endOne.next = startTwo
            return startOne
        else:
            return startTwo