sort

merge.ts

const mergeSort = (arr: number[]): number[] => {
  if (arr.length < 2) {
    return arr;
  }

  const middle = Math.floor(arr.length / 2);
  const left = arr.slice(0, middle);
  const right = arr.slice(middle);

  const sortedLeft = mergeSort(left);
  const sortedRight = mergeSort(right);

  return merge(sortedLeft, sortedRight);
};

const merge = (left, right) => {
  const result = [];

  while (left.length && right.length) {
    if (left[0] <= right[0]) {
      result.push(left.shift());
    } else {
      result.push(right.shift());
    }
  }

  return result.concat(left, right);
};

const nums = [10, 5, 3, 8, 1, 4, 7, 9, 6, 2];

const ans = mergeSort(nums);

console.log(ans);