Introduction

In this blog post, we will explore how to solve the LeetCode problem "912" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like Chatmagic, we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

Problem Statement

Given an array of integers nums, sort the array in ascending order and return it. You must solve the problem without using any built-in functions in O(nlog(n)) time complexity and with the smallest space complexity possible. Example 1: Input: nums = [5,2,3,1] Output: [1,2,3,5] Explanation: After sorting the array, the positions of some numbers are not changed (for example, 2 and 3), while the positions of other numbers are changed (for example, 1 and 5). Example 2: Input: nums = [5,1,1,2,0,0] Output: [0,0,1,1,2,5] Explanation: Note that the values of nums are not necessairly unique. Constraints: 1 <= nums.length <= 5 104 -5 104 <= nums[i] <= 5 * 104

Explanation

Here's an efficient solution to sort an array of integers in ascending order using the Merge Sort algorithm.

• High-Level Approach:

  • Divide: Recursively divide the input array into smaller subarrays until each subarray contains only one element (which is trivially sorted).
  • Conquer: Sort each subarray (base case: a single element is already sorted).
  • Merge: Repeatedly merge the sorted subarrays to produce new sorted subarrays until there is only one sorted array remaining.

• Complexity: O(n log n) time complexity, O(n) space complexity (due to the auxiliary array used in the merge operation). Note that Merge Sort is used due to its O(n log n) time complexity, satisfying the prompt requirement, as opposed to other simpler algorithms, such as Bubble Sort, which are O(n^2).

Code

    def sortArray(nums):
    """
    Sorts an array of integers in ascending order using merge sort.

    Args:
        nums: A list of integers.

    Returns:
        A list of integers sorted in ascending order.
    """

    def merge_sort(arr):
        if len(arr) <= 1:
            return arr

        mid = len(arr) // 2
        left = merge_sort(arr[:mid])
        right = merge_sort(arr[mid:])

        return merge(left, right)

    def merge(left, right):
        merged = []
        i = 0
        j = 0

        while i < len(left) and j < len(right):
            if left[i] <= right[j]:
                merged.append(left[i])
                i += 1
            else:
                merged.append(right[j])
                j += 1

        while i < len(left):
            merged.append(left[i])
            i += 1

        while j < len(right):
            merged.append(right[j])
            j += 1

        return merged

    return merge_sort(nums)