function quickSort<T>(arr: T[]): T[] {
  if (arr.length <= 1) return arr;

  const pivot = arr[Math.floor(arr.length / 2)];
  const left = arr.filter(x => x < pivot);
  const middle = arr.filter(x => x === pivot);
  const right = arr.filter(x => x > pivot);

  return [...quickSort(left), ...middle, ...quickSort(right)];
}

// Example usage:
const numbers = [64, 34, 25, 12, 22, 11, 90];
console.log(quickSort(numbers));