Introduction

In this blog post, we will explore how to solve the LeetCode problem "1749" 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

You are given an integer array nums. The absolute sum of a subarray [numsl, numsl+1, ..., numsr-1, numsr] is abs(numsl + numsl+1 + ... + numsr-1 + numsr). Return the maximum absolute sum of any (possibly empty) subarray of nums. Note that abs(x) is defined as follows: If x is a negative integer, then abs(x) = -x. If x is a non-negative integer, then abs(x) = x. Example 1: Input: nums = [1,-3,2,3,-4] Output: 5 Explanation: The subarray [2,3] has absolute sum = abs(2+3) = abs(5) = 5. Example 2: Input: nums = [2,-5,1,-4,3,-2] Output: 8 Explanation: The subarray [-5,1,-4] has absolute sum = abs(-5+1-4) = abs(-8) = 8. Constraints: 1 <= nums.length <= 105 -104 <= nums[i] <= 104

Explanation

Here's an efficient solution to find the maximum absolute subarray sum:

• Kadane's Algorithm Adaptation: We adapt Kadane's algorithm to find both the maximum and minimum subarray sums.

• Absolute Value: The maximum absolute subarray sum will be the maximum of the absolute value of the maximum subarray sum and the absolute value of the minimum subarray sum. This covers cases where a large negative subarray sum, when made positive, yields the largest absolute sum.

• Runtime Complexity: O(n), Storage Complexity: O(1)

Code

    def maxAbsoluteSum(nums):
    """
    Finds the maximum absolute sum of any (possibly empty) subarray of nums.

    Args:
        nums: An integer array.

    Returns:
        The maximum absolute sum of any subarray of nums.
    """

    max_so_far = 0
    min_so_far = 0
    current_max = 0
    current_min = 0

    for num in nums:
        current_max = max(num, current_max + num)
        max_so_far = max(max_so_far, current_max)

        current_min = min(num, current_min + num)
        min_so_far = min(min_so_far, current_min)

    return max(abs(max_so_far), abs(min_so_far))