Add Two Numbers
Created: January 21, 2019 by [lek-tin]
Last updated: January 21, 2019
You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.
You may assume the two numbers do not contain any leading zero, except the number 0 itself.
Example
Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
Explanation: 342 + 465 = 807.
Solution
# Definition for singly-linked list.
# class ListNode(object):
# def __init__(self, x):
# self.val = x
# self.next = None
# Time: `O(n)`
# Space: O(1)
class Solution(object):
def addTwoNumbers(self, l1, l2):
"""
:type l1: ListNode
:type l2: ListNode
:rtype: ListNode
"""
c1 = l1
c2 = l2
head = ListNode(0)
dummy = head
sum = 0
while c1 != None or c2 != None:
sum //= 10
print(sum)
if c1 != None:
sum += c1.val
c1 = c1.next
if c2 != None:
sum += c2.val
c2 = c2.next
dummy.next = ListNode(sum % 10)
dummy = dummy.next
if sum//10 == 1:
dummy.next = ListNode(1)
return head.next