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

1#include <iostream>
2#include <vector>
#include <unordered_map>
#include <algorithm>

using namespace std;

vector<int> topKFrequent(vector<int>& nums, int k) {
    unordered_map<int, int> freqMap;
    vector<vector<int>> buckets(nums.size() + 1);

    for (int num : nums) {
        freqMap[num]++;
    }

    for (auto& p : freqMap) {
        buckets[p.second].push_back(p.first);
    }

    vector<int> result;
    for (int i = buckets.size() - 1; i >= 0 && result.size() < k; --i) {
        for (int num : buckets[i]) {
            result.push_back(num);
            if (result.size() == k) break;
        }
    }
    return result;
}

int main() {
    vector<int> nums = {1, 1, 1, 2, 2, 3};
    int k = 2;
    vector<int> result = topKFrequent(nums, k);
    for (int num : result) {
        cout << num << " ";
    }
    return 0;
}