Force deduction daily question 06.29 add two numbers

Try to make a daily question 06.29 Addition of two numbers

Is it easy to add two numbers in the title , So nice , Next, let's look at the topic ：

Here are two for you Non empty The linked list of , Represents two nonnegative integers . Each of them is based on The reverse Stored in , And each node can only store a Numbers .

Please add up the two numbers , And returns a linked list representing sum in the same form .

You can assume that in addition to the numbers 0 outside , Neither of these numbers 0 start .

Example 1：

image-20220629135454983

 Input ：l1 = [2,4,3], l2 = [5,6,4]
 Output ：[7,0,8]
 explain ：342 + 465 = 807.

Example 2：

 Input ：l1 = [0], l2 = [0]
 Output ：[0]

Example 3：

 Input ：l1 = [0], l2 = [0]
 Output ：[0]

Tips ：

• The number of nodes in each list is in the range [1, 100] Inside

• 0 <= Node.val <= 9

• The title data guarantees that the number indicated in the list does not contain leading zeros

Then I went into deep thinking ...

After N Hours later, , With a lost lost thought , Start writing code

image-20220629135745842

After a few hours , He's green ヾ(◍°∇°◍)ﾉﾞ

image-20220629135018178

Find a 100%, When I am ecstatic , Take a closer look. , Submit More than 100% Users of , I do ！！！

Here is my junk code

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode() {}
 *     ListNode(int val) { this.val = val; }
 *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 * }
 */
class Solution {
    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        ListNode header = new ListNode();
        ListNode count = header;
        int carryNum = 0, type;
        while (true) {
            type = l1.val + l2.val + carryNum;
            carryNum = type / 10;
            ListNode tempListNode = new ListNode(type % 10);
            count.val = tempListNode.val;
            tempListNode = new ListNode();
            l1 = l1.next;
            l2 = l2.next;
            if (l1 != null || l2 != null) {
                count.next = new ListNode();
                count = count.next;
                if (l1 == null) {
                    l1 = new ListNode(0);
                } else if (l2 == null) {
                    l2 = new ListNode(0);
                }
            } else if (carryNum > 0 && l1 == null && l2 == null) {
                count.next = new ListNode();
                count = count.next;
                l1 = new ListNode(0);
                l2 = new ListNode(0);
            }else {
                break;
            }
        }
        return header;
    }
}

Official code

class Solution {
    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        ListNode head = null, tail = null;
        int carry = 0;
        while (l1 != null || l2 != null) {
            int n1 = l1 != null ? l1.val : 0;
            int n2 = l2 != null ? l2.val : 0;
            int sum = n1 + n2 + carry;
            if (head == null) {
                head = tail = new ListNode(sum % 10);
            } else {
                tail.next = new ListNode(sum % 10);
                tail = tail.next;
            }
            carry = sum / 10;
            if (l1 != null) {
                l1 = l1.next;
            }
            if (l2 != null) {
                l2 = l2.next;
            }
        }
        if (carry > 0) {
            tail.next = new ListNode(carry);
        }
        return head;
    }
}

source ： Power button （LeetCode） link ：https://leetcode.cn/problems/add-two-numbers