30-seconds-of-code/snippets/lcm.md

title, tags

title	tags
lcm	math,recursion,intermediate

Calculates the least common multiple of two or more numbers.

• Use the greatest common divisor (GCD) formula and the fact that lcm(x,y) = x * y / gcd(x,y) to determine the least common multiple.
• The GCD formula uses recursion.

const lcm = (...arr) => {
  const gcd = (x, y) => (!y ? x : gcd(y, x % y));
  const _lcm = (x, y) => (x * y) / gcd(x, y);
  return [...arr].reduce((a, b) => _lcm(a, b));
};

lcm(12, 7); // 84
lcm(...[1, 3, 4, 5]); // 60