Problem link: https://www.codechef.com/PPW12020/problems/ANITGUY1
Difficulty:
moderate
Solution:
#include <bits/stdc++.h>
using namespace std;
// driver code
int main()
{
int t;
cin>>t;
while(t--){
int k,n;
cin>>k>>n;
int arr[n];
for(int i=0;i<n;i++)cin>>arr[i];
sort(arr,arr+n);
int ans=0;
for(int i=0;i<n;i++){
if(binary_search(arr,arr+n,k-arr[i]))ans++;
}
cout << ans/2 << endl;
}
return 0;
}
Time : 0.1sec
Thanks and Regards