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Add to Array-Form of Integer

Problem statement​

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 = 34Output: [1,2,3,4]Explanation: 1200 + 34 = 1234

Example 2:

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

Example 3:

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

Constraints:

  • 1 <= num.length <= 104
  • 0 <= num[i] <= 9
  • num does not contain any leading zeros except for the zero itself.
  • 1 <= k <= 104

My solution​

/**
 * @param {number[]} num
 * @param {number} k
 * @return {number[]}
 */
var addToArrayForm = function(num, k) {
    const numInt = num.join("")
    if (typeof BigInt(numInt) === "bigint") {
        // return [...(BigInt(A.join('')) + BigInt(K) + '')];
        return (BigInt(numInt) + BigInt(k)).toString().split("")
    }
    return (+numInt + k).toString().split("")
};