Submission #1191410

#	Time	Username	Problem	Language	Result	Execution time	Memory
1191410		ulvix	Mountains (NOI20_mountains)	C++20	100 / 100	529 ms	21568 KiB

Mountains

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define all(x) x.begin(),x.end()
const ll sz=1e5+100;
const ll mod=1e9+7;
const ll INF=1e18;
using namespace std;
using namespace __gnu_pbds;
template<class T>
using indexed_multiset=tree<T,null_type,less_equal<T>,rb_tree_tag,tree_order_statistics_node_update>;
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll n;
    cin>>n;
    indexed_multiset<ll> l;
    indexed_multiset<ll> r;
    vector<ll> v(n);
    for(ll i=0;i<n;i++){
        cin>>v[i];
        r.insert(v[i]);
    }
    ll ans=0;
    for(ll i=0;i<n;i++){
        r.erase(r.find_by_order(r.order_of_key(v[i])));
        l.insert(v[i]);
        ll idx=l.order_of_key(v[i]);
        ll idx1=r.order_of_key(v[i]);
        ans+=idx*idx1;
    }
    cout<<ans;

}

• Subtask 1: 2 / 2
• Subtask 2: 4 / 4
• Subtask 3: 9 / 9
• Subtask 4: 36 / 36
• Subtask 5: 28 / 28
• Subtask 6: 9 / 9
• Subtask 7: 12 / 12