题目英文

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.

题目中文

给出两个 非空 的链表用来表示两个非负的整数。其中,它们各自的位数是按照 逆序 的方式存储的,并且它们的每个节点只能存储 一位 数字。

如果,我们将这两个数相加起来,则会返回一个新的链表来表示它们的和。

您可以假设除了数字 0 之外,这两个数都不会以 0 开头。

示例 1

输入:(2 -> 4 -> 3) + (5 -> 6 -> 4)
输出:7 -> 0 -> 8
原因:342 + 465 = 807

示例 2

输入:(3 -> 7) + (9 -> 2)
输出:2 -> 0 -> 1
原因:73 + 29 = 102

算法实现

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     public int val;
 *     public ListNode next;
 *     public ListNode(int x) { val = x; }
 * }
 */
public class Solution {
    public ListNode AddTwoNumbers(ListNode l1, ListNode l2) {
        ListNode result = new ListNode(-1);
        ListNode l3 = result;
        int flag = 0;
        while (l1 != null && l2 != null)
        {
            int a = l1.val;
            int b = l2.val;
            int c = a + b + flag;
            l3.next = new ListNode(c%10);

            flag = c >= 10 ? 1 : 0;
            l1 = l1.next;
            l2 = l2.next;
            l3 = l3.next;
        }

        while (l1 != null)
        {
            int a = l1.val + flag;

            l3.next = new ListNode(a%10);

            flag = a >= 10 ? 1 : 0;
            l1 = l1.next;
            l3 = l3.next;
        }

        while (l2 != null)
        {
            int b = l2.val + flag;

            l3.next = new ListNode(b%10);
            flag = b >= 10 ? 1 : 0;
            l2 = l2.next;
            l3 = l3.next;
        }

        if (flag == 1)
        {
            l3.next = new ListNode(flag);
        }
        return result.next;
    }
}

实验结果

LeetCode实战:两数相加-LMLPHP


相关图文

08-27 23:31