https://programmers.co.kr/learn/courses/30/lessons/12932?language=javascript
function solution(n) {
let answer = [];
const strNumArray = String(n)
.split("")
.reverse();
for (let i = 0; i < strNumArray.length; i++) {
const number = Number(strNumArray[i]);
answer.push(number);
}
return answer;
}