#1296 Divide Array in Sets of K Consecutive Numbers.java

//https://leetcode.com/problems/divide-array-in-sets-of-k-consecutive-numbers/
class Solution {
    public boolean isPossibleDivide(int[] nums, int k) {
        TreeMap<Integer, Integer> count = new TreeMap();
        for (int card: nums) {
            if (!count.containsKey(card))
                count.put(card, 1);
            else
                count.replace(card, count.get(card) + 1);
        }

        while (count.size() > 0) {
            int first = count.firstKey();
            for (int card = first; card < first + k; ++card) {
                if (!count.containsKey(card)) return false;
                int c = count.get(card);
                if (c == 1) count.remove(card);
                else count.replace(card, c - 1);
            }
        }

        return true;
    }
}