First element to occur k times.cpp

//{ Driver Code Starts
#include <bits/stdc++.h>
using namespace std;


// } Driver Code Ends
class Solution{
    public:
    int firstElementKTime(int a[], int n, int k)
    {
        unordered_map<int, int> count_map;
        for (int i=0; i<n; i++)
            count_map[a[i]]++;
     
        for (int i=0; i<n; i++) 
            if (count_map[a[i]] == k)
                return a[i+1];
        return -1;
    }
};

//{ Driver Code Starts.

int main() {
	int t;
	cin >> t;
	while(t--){
	    int n, k;
	    cin >> n >> k;
	    int a[n];
	    for(int i = 0;i<n;i++){
	        cin >> a[i];
	    }
	    Solution ob;
	    cout<<ob.firstElementKTime(a, n, k)<<endl;
	}
	
	return 0;
}
// } Driver Code Ends