88. Merge Sorted Array

Problem

https://leetcode.com/problems/merge-sorted-array/

Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.

Note:
You may assume that nums1 has enough space (size that is greater or equal to m + n) to hold additional elements from nums2. The number of elements initialized in nums1 and nums2 are m and n respectively.

Solution

traverse backward

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

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