TypeScript로 로토6·로토7 추첨 숫자 생성하기

function generateLottoNumbers(lot: 6 | 7): number[] {
  if (![6, 7].includes(lot)) {
    throw new Error('引数は6または7である必要があります');
  }

  const { random } = createMersenneTwister();
  const min = 1, max =  lot === 6 ? 43 : 37

  const numbers = new Set<number>();

  while (numbers.size < lot) {
    numbers.add(Math.floor(random() * (max - min + 1)) + min);
  }

  return [...numbers];
}

export function createMersenneTwister(seed: number = new Date().getTime()) {
  let index = 624;
  const MT = new Array(624);
  MT[0] = seed;

  for (let i = 1; i < 624; i++) {
    MT[i] = (1812433253 * (MT[i - 1] ^ (MT[i - 1] >>> 30)) + i) >>> 0;
  }

  function generateNumbers() {
    for (let i = 0; i < 624; i++) {
      const y = (MT[i] & 0x80000000) + (MT[(i + 1) % 624] & 0x7fffffff);
      MT[i] = MT[(i + 397) % 624] ^ (y >>> 1);
      if (y % 2 !== 0) {
        MT[i] ^= 2567483615;
      }
    }
  }

  function random() {
    if (index >= 624) {
      generateNumbers();
      index = 0;
    }

    let y = MT[index++];
    y ^= (y >>> 11);
    y ^= (y << 7) & 2636928640;
    y ^= (y << 15) & 4022730752;
    y ^= (y >>> 18);

    return (y >>> 0) / 4294967296;
  }

  return { random };
}