merge-sorted-array.js

/**
 * Merge Sorted Array
 *
 * Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.
 *
 * Note:
 *
 * The number of elements initialized in nums1 and nums2 are m and n respectively.
 * You may assume that nums1 has enough space (size that is greater or equal to m + n) to hold additional elements from
 * nums2.
 * Example:
 *
 * Input:
 * nums1 = [1,2,3,0,0,0], m = 3
 * nums2 = [2,5,6],       n = 3
 *
 * Output: [1,2,2,3,5,6]
 */

/**
 * @param {number[]} nums1
 * @param {number} m
 * @param {number[]} nums2
 * @param {number} n
 * @return {void} Do not return anything, modify nums1 in-place instead.
 */
const merge = (nums1, m, nums2, n) => {
  let i = m - 1;
  let j = n - 1;
  let k = m + n - 1;

  while (i >= 0 && j >= 0) {
    if (nums1[i] > nums2[j]) {
      nums1[k--] = nums1[i--];
    } else {
      nums1[k--] = nums2[j--];
    }
  }

  while (j >= 0) {
    nums1[k--] = nums2[j--];
  }
};

export { merge };