merge two sorted arrays O(n)

merge_sorted.ts

const merge = (a: number[], b: number[]): number[] => {
  let length = a.length + b.length;
  let result = Array(length);
  let i = 0, j = 0, k = 0;
  while (i < a.length && j < b.length) {
    if (a[i] < b[j]) {
      result[k] = a[i];
      i += 1;
    } else if (a[i] > b[j]) {
      result[k] = b[j]
      j += 1
    } else {
      result[k] = a[i];
      i += 1;
      k += 1;
      result[k] = b[j];
      j += 1;
    }
    k += 1;
  }
  while (i < a.length) {
    result[k] = a[i];
    i += 1;
    k += 1;
  }

  while (j < b.length) {
    result[k] = b[j];
    j += 1;
    k += 1;
  }
  return result;
};


console.log(JSON.stringify(merge(
  [0, 1, 2, 3, 5, 14, 19],
  [0,4, 7, 8, 9])));