1677A - Tokitsukaze and Strange Inequality - CodeForces Solution

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


void solve() {
	int n;
	cin >> n;
	vector<int> a(n);
	for(int i = 0; i < n; i++) {
		cin >> a[i];
	}
	ll ans = 0;
	vector<int> cnt(n);
	for(int b = 0; b < n; b++) {
		int d = 0;
		for(int c = n - 1; c > b; c--) {
			ans += cnt[c] * d;
			cnt[c] += a[b] < a[c];
			d += a[b] > a[c];
		}
	}
	cout << ans << "\n";
} 


int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);


	int T = 1;
	cin >> T;
	while(T--) solve();
	
	return 0;
}