dsaArray17.cpp

//{ Driver Code Starts
//Initial template for C++

#include <bits/stdc++.h>
using namespace std;

// } Driver Code Ends
//User function template for C++

class Solution{   
public:
    int getPairsCount(int a[], int n, int k) {
        // code here
        map<int,int>m;
        for(int i=0;i<n;i++){
            m[a[i]]++;
        }
        int count=0;
        for(int i=0;i<n;i++){
            count+=m[k-a[i]];
            if(k-a[i]==a[i]){
                count--;
            }
        }
        return count/2;
    }
};

//{ Driver Code Starts.

int main() {
    int t;
    cin >> t;
    while (t--) {
        int n, k;
        cin >> n >> k;
        int arr[n];
        for (int i = 0; i < n; i++) {
            cin >> arr[i];
        }
        Solution ob;
        auto ans = ob.getPairsCount(arr, n, k);
        cout << ans << "\n";
    }
    
    return 0;
}
// } Driver Code Ends