Introduction

In this blog post, we will explore how to solve the LeetCode problem "914" 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 deck where deck[i] represents the number written on the ith card. Partition the cards into one or more groups such that: Each group has exactly x cards where x > 1, and All the cards in one group have the same integer written on them. Return true if such partition is possible, or false otherwise. Example 1: Input: deck = [1,2,3,4,4,3,2,1] Output: true Explanation: Possible partition [1,1],[2,2],[3,3],[4,4]. Example 2: Input: deck = [1,1,1,2,2,2,3,3] Output: false Explanation: No possible partition. Constraints: 1 <= deck.length <= 104 0 <= deck[i] < 104

Explanation

Here's the breakdown of the solution:

• Count Card Frequencies: Determine how many times each number appears in the deck. This is essential to know the size of potential groups.
• Find the Greatest Common Divisor (GCD): The size of any valid group must be a divisor of the count of each card number. Therefore, find the GCD of all the counts. If the GCD is greater than 1, it means there is a common group size that can divide all the card counts.

• Check if GCD > 1: If the GCD calculated is greater than 1, it means a partition into groups of size GCD is possible.

• Runtime Complexity: O(N + M log M), where N is the length of the deck and M is the number of unique elements in the deck. Storage Complexity: O(M), where M is the number of unique elements in the deck.

Code

    from collections import Counter
from math import gcd

def hasGroupsSizeX(deck: list[int]) -> bool:
    """
    Determines if the given deck of cards can be partitioned into groups such that each group has the same size (x > 1) and all cards in a group have the same number.

    Args:
        deck: A list of integers representing the numbers on the cards.

    Returns:
        True if the deck can be partitioned as described, False otherwise.
    """
    counts = Counter(deck)
    group_size = 0
    for count in counts.values():
        group_size = gcd(group_size, count)

    return group_size > 1