1import java.util.*;
2
3class Solution {
4    public int[] topKFrequent(int[] nums, int k) {
5        Map<Integer, Integer> freqMap = new HashMap<>();
6        for (int num : nums) {
7            freqMap.put(num, freqMap.getOrDefault(num, 0) + 1);
8        }
9
10        PriorityQueue<Integer> minHeap = new PriorityQueue<>((a, b) -> freqMap.get(a) - freqMap.get(b));
11        for (int num : freqMap.keySet()) {
12            minHeap.add(num);
13            if (minHeap.size() > k) {
14                minHeap.poll();
15            }
16        }
17
18        int[] result = new int[k];
19        for (int i = k - 1; i >= 0; i--) {
20            result[i] = minHeap.poll();
21        }
22        return result;
23    }
24
25    public static void main(String[] args) {
26        Solution sol = new Solution();
27        int[] nums = {1,1,1,2,2,3};
28        int k = 2;
29        int[] result = sol.topKFrequent(nums, k);
30        System.out.println(Arrays.toString(result));
31    }
32}
33

1using System;
2using System.Collections.Generic;
using System.Linq;

public class Solution {
    public int[] TopKFrequent(int[] nums, int k) {
        var freqMap = new Dictionary<int, int>();
        foreach (var num in nums) {
            if (!freqMap.ContainsKey(num))
                freqMap[num] = 0;
            freqMap[num]++;
        }

        List<int>[] buckets = new List<int>[nums.Length + 1];
        foreach (var pair in freqMap) {
            int freq = pair.Value;
            if (buckets[freq] == null)
                buckets[freq] = new List<int>();
            buckets[freq].Add(pair.Key);
        }

        List<int> res = new List<int>();
        for (int i = buckets.Length - 1; i >= 0 && res.Count < k; --i) {
            if (buckets[i] != null)
                res.AddRange(buckets[i].ToArray());
        }

        return res.Take(k).ToArray();
    }

    public static void Main(string[] args) {
        int[] nums = new int[] {1, 1, 1, 2, 2, 3};
        int k = 2;
        Solution sol = new Solution();
        int[] result = sol.TopKFrequent(nums, k);
        Console.WriteLine(string.Join(", ", result));
    }
}