题目:
给定两个有序链表,返回将这两个链表合并后的有序链表
解题思路:
对于链表操作,需要注意指针的使用,用两个指针遍历这两个链表,将当前两个指针的较小的一个内容接在返回链表的最后,再将该较小指针后移一位,直到其中一个指针的内容为空,则结束
代码(python):
# Definition for singly-linked list.
# class ListNode(object):
# def __init__(self, x):
# self.val = x
# self.next = None
class Solution(object):
def mergeTwoLists(self, l1, l2):
"""
:type l1: ListNode
:type l2: ListNode
:rtype: ListNode
"""
if l2==None:
return l1
if l1==None:
return l2
if l1.val>l2.val:
r1 = l2
l2 = l2.next
else:
r1 = l1
l1 = l1.next
r2 = r1
while(l1!=None or l2!=None):
if l1==None:
r1.next = l2
return r2
if l2==None:
r1.next = l1
return r2
if l1.val>l2.val:
r1.next = l2
l2 = l2.next
r1 = r1.next
continue
if l1.val<=l2.val:
r1.next = l1
l1 = l1.next
r1 = r1.next
continue
return r2