LeetCode : 347. Top K Frequent Elements

class Solution {
    public int[] topKFrequent(int[] nums, int k) {

        HashMap<Integer, Integer> map = new HashMap<>();

        for (int num : nums) {
            map.put(num, map.getOrDefault(num, 0) + 1);
        }

        PriorityQueue<int[]> pQueue = new PriorityQueue<>(
                (newItem, oldItem) -> Integer.compare(oldItem[1], newItem[1]));

        for (Map.Entry<Integer, Integer> entries : map.entrySet()) {
            pQueue.add(new int[] { // [1]
                    entries.getKey(),
                    entries.getValue()
            });
        }

        int[] ans = new int[k];
        for (int i = 0; i < k; i++) {
            ans[i] = pQueue.poll()[0];
        }
        return ans;
    }
}