Introduction

In this blog post, we will explore how to solve the LeetCode problem "2395" 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 a 0-indexed integer array nums, determine whether there exist two subarrays of length 2 with equal sum. Note that the two subarrays must begin at different indices. Return true if these subarrays exist, and false otherwise. A subarray is a contiguous non-empty sequence of elements within an array. Example 1: Input: nums = [4,2,4] Output: true Explanation: The subarrays with elements [4,2] and [2,4] have the same sum of 6. Example 2: Input: nums = [1,2,3,4,5] Output: false Explanation: No two subarrays of size 2 have the same sum. Example 3: Input: nums = [0,0,0] Output: true Explanation: The subarrays [nums[0],nums[1]] and [nums[1],nums[2]] have the same sum of 0. Note that even though the subarrays have the same content, the two subarrays are considered different because they are in different positions in the original array. Constraints: 2 <= nums.length <= 1000 -109 <= nums[i] <= 109

Explanation

• Calculate Subarray Sums: Iterate through the array, calculating the sum of each subarray of length 2.
  • Efficient Sum Tracking: Use a set to store the sums encountered so far. If a sum is already in the set, it means we've found two subarrays with the same sum.
  • Early Exit: Return True as soon as a duplicate sum is found to optimize for early termination.

• Time Complexity: O(n), where n is the length of the input array nums. Space Complexity: O(n) in the worst case, as the set might store up to n-1 distinct sums.

Code

    def find_subarrays(nums):
    """
    Given a 0-indexed integer array nums, determine whether there exist two subarrays of length 2 with equal sum.
    Note that the two subarrays must begin at different indices.
    Return true if these subarrays exist, and false otherwise.

    Args:
        nums (List[int]): A list of integers.

    Returns:
        bool: True if two subarrays of length 2 with equal sum exist at different indices, False otherwise.
    """
    seen_sums = set()
    for i in range(len(nums) - 1):
        current_sum = nums[i] + nums[i+1]
        if current_sum in seen_sums:
            return True
        seen_sums.add(current_sum)
    return False