Merge Sorted Array
This is an elegant way to make it in O(m+n) from leetcode discussion sktlez.
/**
* @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 insInd = nums1.length - 1; //Position to start inserting into nums1 array
let i = m - 1; //index to the end of nums1 array (right before the 0's start)
let j = nums2.length - 1; //index to the end of nums2 array
//Merge the arrays
while(j >= 0 && i >= 0) {
if (nums2[j] >= nums1[i]) {
nums1[insInd--] = nums2[j--];
} else {
nums1[insInd--] = nums1[i--];
}
}
//Copy over any remaining elements
while (i >= 0) {
nums1[insInd--] = nums1[i--];
}
//Copy over any remaining elements
while (j >= 0) {
nums1[insInd--] = nums2[j--];
}
};