Introduction

In this blog post, we will explore how to solve the LeetCode problem "1464" 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 the array of integers nums, you will choose two different indices i and j of that array. Return the maximum value of (nums[i]-1)(nums[j]-1). Example 1: Input: nums = [3,4,5,2] Output: 12 Explanation: If you choose the indices i=1 and j=2 (indexed from 0), you will get the maximum value, that is, (nums[1]-1)(nums[2]-1) = (4-1)(5-1) = 34 = 12. Example 2: Input: nums = [1,5,4,5] Output: 16 Explanation: Choosing the indices i=1 and j=3 (indexed from 0), you will get the maximum value of (5-1)*(5-1) = 16. Example 3: Input: nums = [3,7] Output: 12 Constraints: 2 <= nums.length <= 500 1 <= nums[i] <= 10^3

Explanation

Here's the breakdown of the solution:

• Find the two largest numbers: The problem asks to maximize (nums[i]-1)*(nums[j]-1). To achieve this, we should select the two largest numbers in the array for nums[i] and nums[j].

• Calculate the product: Once we have the two largest numbers, we simply compute (largest - 1) * (second_largest - 1).

• Time Complexity: O(n), Space Complexity: O(1)

Code

    def maxProduct(nums: list[int]) -> int:
    """
    Given the array of integers nums, you will choose two different indices i and j of that array.
    Return the maximum value of (nums[i]-1)*(nums[j]-1).
    """
    largest = 0
    second_largest = 0

    for num in nums:
        if num > largest:
            second_largest = largest
            largest = num
        elif num > second_largest:
            second_largest = num

    return (largest - 1) * (second_largest - 1)