提交时间:2024-03-15 17:28:15

运行 ID: 138341

#include <iostream> #define ll long long using namespace std; ll a[1000005], tot[1000005], cnt[1000005]; int main() { ll n; cin >> n; ll sum = 0; for(ll i = 1; i <= n; i++) { cin >> a[i]; cnt[i] = 1; } for(ll i = 1; i <= n; i++) { for(ll j = 1; j <= i; j++) { if(a[i] < a[j]) { tot[i] += cnt[i]; tot[j] += cnt[j]; cnt[i]++; cnt[j]++; } } } for(ll i = 1; i <= n; i++) sum += tot[i]; cout << sum << endl; return 0; }