Comparing Two Approaches to LeetCode #88: Merge Sorted Array

The article discusses the LeetCode problem #88, titled ‘Merge Sorted Array,’ which challenges programmers to merge two sorted integer arrays into one, in-place and in non-decreasing order. The original problem provides two arrays, nums1 and nums2, and the respective counts of initialized elements in each, m and n. The task is to merge nums2 into nums1 without returning a new array.

The author initially shares a solution using an auxiliary array (a clone of nums1) and compares values iteratively between nums1 and nums2. While functional, this method is criticized for being lengthy and harder to read. The author then introduces a more optimized solution inspired by a ‘Two Pointer’ approach (also referred to as a ‘Three Pointer’ approach), where pointers start from the end of the arrays and elements are merged in-place by comparing the largest values and inserting them at the correct position from the back.

The improved version reduces code length, improves clarity, and performs better in terms of memory usage. The post reflects on lessons learned, such as efficient array copying and minimizing redundant code. Overall, it emphasizes algorithmic optimization and clean coding practices while solving a classic problem on LeetCode.