Median of Two Sorted Arrays

Problem statement

Given two sorted arrays nums1 and nums2 of size m and n respectively, return the median of the two sorted arrays.

The overall run time complexity should be O(log (m+n)).

Example 1:

Input: nums1 = [1,3], nums2 = [2]Output: 2.00000Explanation: merged array = [1,2,3] and median is 2.

Example 2:

Input: nums1 = [1,2], nums2 = [3,4]Output: 2.50000Explanation: merged array = [1,2,3,4] and median is (2 + 3) / 2 = 2.5.

Constraints:

• nums1.length == m
• nums2.length == n
• 0 <= m <= 1000
• 0 <= n <= 1000
• 1 <= m + n <= 2000
• -106 <= nums1[i], nums2[i] <= 106

My solution

/**
 * @param {number[]} nums1
 * @param {number[]} nums2
 * @return {number}
 */
var findMedianSortedArrays = function(nums1, nums2) {
    const totalLen = nums1.length + nums2.length;
    let num1Id = 0;
    let num2Id = 0;
    let curr;
    let last;
    
    while(num1Id + num2Id <= totalLen/2) {
        if (curr !== undefined) {
            last = curr
        }
        
        if (nums2[num2Id] === undefined || nums1[num1Id] < nums2[num2Id]) {
            curr = nums1[num1Id];
            num1Id++;
        } else if (nums1[num1Id] === undefined || nums1[num1Id] > nums2[num2Id]) {
            curr = nums2[num2Id];
            num2Id++;
        } else {
            curr = nums2[num2Id];
            num2Id++;
        }
    }
    return totalLen % 2 === 0 ? (curr + last) /2 : curr;
};