LeetcodeJan 17, 2026

Add to Array-Form of Integer

Hazrat Ali

Leetcode

The array-form of an integer num is an array representing its digits in left to right order.

  • For example, for num = 1321, the array form is [1,3,2,1].

Given num, the array-form of an integer, and an integer k, return the array-form of the integer num + k.

 

Example 1:

Input: num = [1,2,0,0], k = 34
Output: [1,2,3,4]
Explanation: 1200 + 34 = 1234

Example 2:

Input: num = [2,7,4], k = 181
Output: [4,5,5]
Explanation: 274 + 181 = 455

Example 3:

Input: num = [2,1,5], k = 806
Output: [1,0,2,1]
Explanation: 215 + 806 = 1021

Solution
var addToArrayForm = function(num, k) {
    let i = num.length - 1;
    let carry = k;
    let result = [];

    while (i >= 0 || carry > 0) {
        if (i >= 0) {
            carry += num[i];
            i--;
        }
        result.push(carry % 10);
        carry = Math.floor(carry / 10);
    }

    return result.reverse();
};



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