LeetCode:1669. 合并两个链表(python3)

Posted 2021-06-24 南岸青栀*

文章目录

• 1669. 合并两个链表
• • 方法：三指针法

1669. 合并两个链表

方法：三指针法

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution:
    def mergeInBetween(self, list1: ListNode, a: int, b: int, list2: ListNode) -> ListNode:
        cur = ListNode(-1)
        cur.next = list1
        #定义三个指针 an,a_pre,bn
        an,a_pre = cur.next,cur
        bn = cur.next
        countb = counta = 0
        #同时寻找第a个节点和第b个节点
        while countb <= b:
            if counta < a:
                an = an.next
                a_pre = a_pre.next
                counta += 1
            bn = bn.next
            countb += 1
        #开始连接链表
        a_pre.next = list2
        while list2.next:
            list2 = list2.next
        list2.next = bn
        return cur.next