# LeetCode 021Merge Two Sorted Lists

## LeetCode 021 Merge Two Sorted Lists Problem

``````# 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
#         """
class Solution(object):
def mergeTwoLists(self, l1, l2):
while l1 is not None and l2 is not None:
if l1.val <= l2.val:
pos.next = l1
l1 = l1.next
else:
pos.next = l2
l2 = l2.next
pos = pos.next
# merge residual l1
if l1 is not None:
pos.next = l1
# merge residual l2
if l2 is not None:
pos.next = l2

# def mergeTwoLists(self, l1, l2):
#     # recursive
#     if l1 is None:
#         return l2
#     elif l2 is None:
#         return l1
#     if l1.val <= l2.val:
#         l1.next = self.mergeTwoLists(l1.next, l2)
#         return l1
#     else:
#         l2.next = self.mergeTwoLists(l1, l2.next)
#         return l2

``````

## List of all Merge Two Sorted Lists problems

Leetcode 021 Merge Two Sorted Lists problem solution in python3 with explanation. This is the best place to expand your knowledge and get prepared for your next interview.

self.val = x

self.next = None

class Solution(object):

def mergeTwoLists(self, l1, l2):

"""

:type l1: ListNode

:type l2: ListNode

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