链表16--两个数相加

秒速五厘米 2022-05-25 07:19 136阅读 0赞

1、题目：

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

2、解答：就是两个数的相加，两个链表的结点彼此相加即可。

3、C++代码

class Solution {
    public:
        ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
           int sum = 0;
            ListNode *dummy = new ListNode(0),*curr;
            curr = dummy;
            while(l1 || l2 || sum){
                if(l1){
                    sum += l1->val;
                    l1 = l1->next;
                }
                if(l2){
                    sum += l2->val;
                    l2 = l2->next;
                }
                curr->next = new ListNode(sum % 10);
                curr = curr->next;
                sum /= 10;
            }
            return dummy->next;
        }
    };

python代码

class Solution:
        def addTwoNumbers(self, l1, l2):
            """
            :type l1: ListNode
            :type l2: ListNode
            :rtype: ListNode
            """
            dummy = ListNode(0)
            curr = dummy
            plus = 0
            while l1 or l2 or plus:
                num1,num2 = 0,0
                if l1:
                    num1 = l1.val
                    l1 = l1.next
                if l2:
                    num2 = l2.val
                    l2 = l2.next
                plus,num = divmod(num1+num2+plus,10)
                curr.next = ListNode(num)
                curr = curr.next
            return dummy.next