CF1598D.Training Session 1700—— 组合数学

1598D 

// Decline is inevitable,
// Romance will last forever.
//#include <bits/stdc++.h>
#include <iostream>
#include <cmath>
#include <cstring>
#include <string>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <deque>
#include <vector>
using namespace std;
#define mst(a, x) memset(a, x, sizeof(a))
#define INF 0x3f3f3f3f
//#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define fi first
#define se second
#define ll long long
#define int long long
const int maxn = 2e5 + 10;
const int maxm = 1e3 + 10;
const int P = 1e4 + 7;
int a[maxn], b[maxn];
int cnt[maxn], sum[maxn];
void solve() {
    int n;
    cin >> n;
    for(int i = 1; i <= n; i++) {
        cnt[i] = sum[i] = 0;
    }
    ll ans = 1ll * n * (n-1) * (n-2) / 6;
    for(int i =1; i <= n; i++) {
        cin >> a[i] >> b[i];
        cnt[a[i]]++;
        sum[b[i]]++;
    }
    for(int i = 1; i <= n; i++) {
        ans -= (cnt[a[i]]-1) * (sum[b[i]]-1);
    }
    cout << ans << '\n';
    
}
signed main() {
    ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
//    int T; scanf("%d", &T); while(T--)
//    freopen("1.txt","r",stdin);
//    freopen("output.txt","w",stdout);
    int T; cin >> T;while(T--)
    solve();
    return 0;
}