[LeetCode]Add Two Numbers

Add Two Numbers

相加兩個非負整數的鏈表，計算加總後的數字。

Example 1

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

Example 2

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

Example 3

Input: l1 = [9,9,9,9,9,9,9], l2 = [9,9,9,9]
Output: [8,9,9,9,0,0,0,1]

解法

PHP

/**
 * Definition for a singly-linked list.
 * class ListNode {
 *     public $val = 0;
 *     public $next = null;
 *     function __construct($val = 0, $next = null) {
 *         $this->val = $val;
 *         $this->next = $next;
 *     }
 * }
 */
class Solution {

    /**
     * @param ListNode $l1
     * @param ListNode $l2
     * @return ListNode
     */
    function addTwoNumbers($l1, $l2) {
       $sum = 0;
        $carry = 0;
        $arr_sum = [];

        while ($l1 != '' || $l2 != '') {
            $sum = $l1->val + $l2->val + $carry;

            if ($sum >= 10) {
                $carry = intval($sum / 10);
                $sum = $sum % 10;
            } else {
                $carry = 0;
            }
            $arr_sum[] = $sum;

            $l1 = $l1->next;
            $l2 = $l2->next;
        }
        if ($carry > 0)
            $arr_sum[] = $carry;

        $result_list = new ListNode();
        $res = $result_list;
        foreach ($arr_sum as $num) {
            $res->next = new ListNode($num);
            $res = $res->next;
        }

        return $result_list->next;
    }
}

Python

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next

class Solution:
    def addTwoNumbers(self, l1, l2):
        sum = 0
        carry = 0
        arr_sum = []

        while l1 or l2:
            val_1 = val_2 = 0

            if l1:
                val_1 = l1.val
                l1 = l1.next
            if l2:
                val_2 = l2.val
                l2 = l2.next

            sum = val_1 + val_2 + carry

            carry = 0
            if sum >= 10:
                carry = int(sum / 10)
                sum %= 10
            arr_sum.append(sum)

        if carry > 0:
            arr_sum.append(carry)

        result_list = ListNode()
        res = result_list
        for num in arr_sum:
            res.next = ListNode(num)
            res = res.next

        return result_list.next