Introduction

In this blog post, we will explore how to solve the LeetCode problem "2961" 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 a 0-indexed 2D array variables where variables[i] = [ai, bi, ci, mi], and an integer target. An index i is good if the following formula holds: 0 <= i < variables.length ((aibi % 10)ci) % mi == target Return an array consisting of good indices in any order. Example 1: Input: variables = [[2,3,3,10],[3,3,3,1],[6,1,1,4]], target = 2 Output: [0,2] Explanation: For each index i in the variables array: 1) For the index 0, variables[0] = [2,3,3,10], (23 % 10)3 % 10 = 2. 2) For the index 1, variables[1] = [3,3,3,1], (33 % 10)3 % 1 = 0. 3) For the index 2, variables[2] = [6,1,1,4], (61 % 10)1 % 4 = 2. Therefore we return [0,2] as the answer. Example 2: Input: variables = [[39,3,1000,1000]], target = 17 Output: [] Explanation: For each index i in the variables array: 1) For the index 0, variables[0] = [39,3,1000,1000], (393 % 10)1000 % 1000 = 1. Therefore we return [] as the answer. Constraints: 1 <= variables.length <= 100 variables[i] == [ai, bi, ci, mi] 1 <= ai, bi, ci, mi <= 103 0 <= target <= 103

Explanation

• Iterate and Evaluate: The solution iterates through the variables array. For each index i, it calculates the result of the given formula ((aibi % 10)ci) % mi.
  • Check for Target: The calculated result is then compared with the target value.
  • Collect Good Indices: If the calculated result is equal to the target, the index i is added to the list of good indices.

• Runtime Complexity: O(n), where n is the length of the variables array. Storage Complexity: O(k), where k is the number of good indices.

Code

    def getGoodIndices(variables, target):
    """
    Finds the good indices in the variables array based on the given formula.

    Args:
        variables: A 0-indexed 2D array where variables[i] = [ai, bi, ci, mi].
        target: An integer.

    Returns:
        An array consisting of good indices in any order.
    """

    good_indices = []
    for i in range(len(variables)):
        a, b, c, m = variables[i]
        result = pow(a % 10, b, 10)
        result = pow(result, c, m)
        if result == target:
            good_indices.append(i)
    return good_indices