mergeSortedArray.js

/*
88. Merge Sorted Array
You are given two integer arrays nums1 and nums2, sorted in non-decreasing order, and two integers m and n, representing the number of elements in nums1 and nums2 respectively.
Merge nums1 and nums2 into a single array sorted in non-decreasing order
The final sorted array should not be returned by the function, but instead be stored inside the array nums1. To accommodate this, nums1 has a length of m + n, where the first m elements denote the elements that should be merged, and the last n elements are set to 0 and should be ignored. nums2 has a length of n.
 */

function merge(nums1, m, nums2, n){
    //create a copy of the 1st array
    let nums1Copy = nums1.slice(0,m)

    //create two pointers pointing at 2 arrays
    let p1 = 0
    let p2 = 0

    for(let i=0; i<m+n; i++){
        if(p2>= n || (p1 < m && nums1Copy[p1] < nums2[p2])){ //checks all corner cases if the pointers run out of the elements
        nums1[i] = nums1Copy[p1]
        p1++
    } else {
        nums1[i] = nums2[p2]
        p2++
    }
    }
    
}