Bulls and Cows

export function getHint(secret: string, guess: string): string {
  const n = secret.length;
  const secrets = new Array(10).fill(0);
  const guesses = new Array(10).fill(0);
 
  let [bulls, cows] = [0, 0];
  for (let i = 0; i < n; i++) {
    if (secret[i] === guess[i]) {
      bulls++;
    } else {
      secrets[parseInt(secret[i])]++;
      guesses[parseInt(guess[i])]++;
    }
  }
 
  for (let i = 0; i < 10; i++) {
    cows += Math.min(secrets[i], guesses[i]);
  }
  return `${bulls}A${cows}B`;
}