素因数分解

primes.js

'use strict';

// 自然数nを素因数分解して、素因数の配列を返す.
function calcPrimeFactor(n) {
  const result = [];
  let x = n;
  for (let i = 2; i * i <= x; i++) {
    while (x % i === 0) {
      result.push(i);
      x /= i;
    }
  }
  if (x !== 1) {
    result.push(x);
  }
  return result;
}

console.log(calcPrimeFactor(286));
console.log(calcPrimeFactor(20211225));