1#include <iostream>
2#include <vector>
3#include <unordered_map>
4#include <queue>
5
6using namespace std;
7
8vector<int> topKFrequent(vector<int>& nums, int k) {
9    unordered_map<int, int> freqMap;
10    for (int num : nums) {
11        freqMap[num]++;
12    }
13
14    auto compare = [&](int a, int b) { return freqMap[a] > freqMap[b]; };
15    priority_queue<int, vector<int>, decltype(compare)> minHeap(compare);
16
17    for (auto& p : freqMap) {
18        minHeap.push(p.first);
19        if (minHeap.size() > k) {
20            minHeap.pop();
21        }
22    }
23
24    vector<int> result;
25    while (!minHeap.empty()) {
26        result.push_back(minHeap.top());
27        minHeap.pop();
28    }
29    return result;
30}
31
32int main() {
33    vector<int> nums = {1, 1, 1, 2, 2, 3};
34    int k = 2;
35    vector<int> result = topKFrequent(nums, k);
36    for (int num : result) {
37        cout << num << " ";
38    }
39    return 0;
40}
41

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));
    }
}