LeetCode----Add Two Numbers

Add Two Numbers

You are given two linked lists representing two non-negative numbers. 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.

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8

分析：

给定两个链表，按位相加。

代码：

# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution(object):
    def addTwoNumbers(self, l1, l2):
        """
        :type l1: ListNode
        :type l2: ListNode
        :rtype: ListNode
        """
        p1 = l1
        p2 = l2
        end = None
        pn = 0
        n = 0
        nm = 0
        isFirst = True
        while p1 or p2:
            if p1 and p2:
                n = p1.val + p2.val + pn
                nm = n % 10
                pn = n / 10
                p1.val = nm
                end = p1
                p1 = p1.next
                p2 = p2.next
            elif p1:
                n = p1.val + pn
                nm = n % 10
                pn = n / 10
                p1.val = nm
                end = p1
                p1 = p1.next
            else:
                n = p2.val + pn
                nm = n % 10
                pn = n / 10
                p2.val = nm
                if isFirst:
                    end.next = p2
                    isFirst = False
                end = p2
                p2 = p2.next
        if pn:
            end.next = ListNode(pn)
        return l1