X of a Kind in a Deck of Cards

Problem statement

In a deck of cards, each card has an integer written on it.

Return true if and only if you can choose X >= 2 such that it is possible to split the entire deck into 1 or more groups of cards, where:

• Each group has exactly X cards.
• All the cards in each group have the same integer.

Example 1:

Input: deck = [1,2,3,4,4,3,2,1]Output: trueExplanation: Possible partition [1,1],[2,2],[3,3],[4,4].

Example 2:

Input: deck = [1,1,1,2,2,2,3,3]Output: falseExplanation: No possible partition.

Constraints:

• 1 <= deck.length <= 104
• 0 <= deck[i] < 104

My solution

/**
 * @param {number[]} deck
 * @return {boolean}
 */
var hasGroupsSizeX = function(deck) {
    if (deck.length === 1) {
        return false
    }
    
    const map = new Map();
    
    for (const num of deck) {
        if (!map.has(num)) {
            map.set(num, 0)
        }
        map.set(num, map.get(num) + 1)
    }
    
    let minGroup;
    // console.log(map)
    for (const count of map.values()) {
        // console.log(minGroup)
        if (minGroup === undefined) {
            minGroup = count;
        } else {
            minGroup = gcd(minGroup, count)
        }
        
    }
    
    // console.log(minGroup)
    
    if (minGroup < 2) {
        return false
    }
    
    for (const count of map.values()) {
        if (count % minGroup !== 0) {
            return false
        }
    }
        
    return true;
};

function lcm (a, b) {
    let gcdValue = gcd(a, b);
    return (a * b) / gcdValue;
}

function gcd(a, b) {
    if (b === 0) {
        return a
    }
    
    return gcd(b, a % b)
}