Integer Division ⧉

If we find some number x is equal to others we've seen when divided by d, our new number will create a pair with each of the previous numerators that map to x/d. Therefore, we simply add the previous count and continue. Keep a map of numerator : quotient pairs for constant access to previous divisions.

integer.cpp

integer.py

#include <iostream>
#include <unordered_map>
using ll = long long;
using namespace std;
int main () {
    int n;
    ll d;
    cin >> n >> d;
    unordered_map<ll,ll> v;
    ll total = 0;
    for (int i = 0; i < n; ++i) {
        ll x; cin >> x;
        total += v[x/d]++;
    }
    cout << total << '\n';
}

If you found this solution helpful, consider leaving a star!