Introduction

In this blog post, we will explore how to solve the LeetCode problem "2554" 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 banned and two integers n and maxSum. You are choosing some number of integers following the below rules: The chosen integers have to be in the range [1, n]. Each integer can be chosen at most once. The chosen integers should not be in the array banned. The sum of the chosen integers should not exceed maxSum. Return the maximum number of integers you can choose following the mentioned rules. Example 1: Input: banned = [1,6,5], n = 5, maxSum = 6 Output: 2 Explanation: You can choose the integers 2 and 4. 2 and 4 are from the range [1, 5], both did not appear in banned, and their sum is 6, which did not exceed maxSum. Example 2: Input: banned = [1,2,3,4,5,6,7], n = 8, maxSum = 1 Output: 0 Explanation: You cannot choose any integer while following the mentioned conditions. Example 3: Input: banned = [11], n = 7, maxSum = 50 Output: 7 Explanation: You can choose the integers 1, 2, 3, 4, 5, 6, and 7. They are from the range [1, 7], all did not appear in banned, and their sum is 28, which did not exceed maxSum. Constraints: 1 <= banned.length <= 104 1 <= banned[i], n <= 104 1 <= maxSum <= 109

Explanation

Here's a breakdown of the solution, followed by the code:

• High-Level Approach:

  • Create a set of banned numbers for fast lookup.
  • Iterate through numbers from 1 to n, adding eligible numbers to a sum and incrementing the count of chosen numbers. Stop when the sum exceeds maxSum.
  • Return the count of chosen numbers.

• Complexity:

  • Runtime Complexity: O(n) (due to the loop iterating up to n)
  • Storage Complexity: O(b) (where 'b' is the number of banned integers, for storing the banned set)

Code

    def max_number_of_integers(banned, n, maxSum):
    """
    Calculates the maximum number of integers that can be chosen according to the given rules.

    Args:
        banned: A list of integers that cannot be chosen.
        n: The upper bound of the range of integers to choose from (1 to n).
        maxSum: The maximum sum allowed for the chosen integers.

    Returns:
        The maximum number of integers that can be chosen.
    """

    banned_set = set(banned)
    count = 0
    current_sum = 0

    for i in range(1, n + 1):
        if i not in banned_set:
            if current_sum + i <= maxSum:
                current_sum += i
                count += 1
            else:
                break  # Stop when the sum exceeds maxSum

    return count