// C++ implementation to find k numbers with most 
// occurrences in the given array 
#include <bits/stdc++.h> 
 
using namespace std; 
 
// comparison function defined for the priority queue 
struct compare 
{ 
    bool operator()(pair<int, int> p1, pair<int, int> p2) 
    { 
        // if frequencies of two elements are same 
        // then the larger number should come first 
        if (p1.second == p2.second) 
            return p1.first < p2.first; 
 
        // insert elements in the priority queue on the basis of 
        // decreasing order of frequencies     
        return p1.second < p2.second;     
    } 
}; 
 
// funnction to print the k numbers with most occurrences 
void print_N_mostFrequentNumber(int arr[], int n, int k) 
{ 
    // unordered_map 'um' implemented as frequency hash table 
    unordered_map<int, int> um; 
    for (int i = 0; i<n; i++) 
        um[arr[i]]++; 
 
    // store the elements of 'um' in the vector 'freq_arr'         
    vector<pair<int, int> > freq_arr(um.begin(), um.end()); 
 
    // priority queue 'pq' implemented as max heap on the basis 
    // of the comparison operator 'compare' 
    // element with the highest frequency is the root of 'pq' 
    // in case of conflicts, larger element is the root 
    priority_queue<pair<int, int>, vector<pair<int, int> >,  
                           compare> pq(um.begin(), um.end()); 
 
    // display the top k numbers 
    cout << k << " numbers with most occurrences are:\n"; 
    for (int i = 1; i<= k; i++) 
    { 
        cout << pq.top().first << " "; 
        pq.pop(); 
    }             
} 
 
// Driver program to test above 
int main() 
{ 
    int arr[] = {3, 1, 4, 4, 5, 2, 6, 1}; 
    int n = sizeof(arr) / sizeof(arr[0]); 
    int k = 2; 
    print_N_mostFrequentNumber(arr, n, k); 
    return 0; 
} 

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