Submission #1191311

#	Time	Username	Problem	Language	Result	Execution time	Memory
1191311		kamal1122333	Mountains (NOI20_mountains)	C++20	100 / 100	574 ms	21620 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 pb push_back
#define f first
#define s second
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(){
    ll n;
    cin>>n;
    indexed_multiset<ll> mst1;
    indexed_multiset<ll> mst2;
    vector<ll> v(n);
    for(ll i=0;i<n;i++){
        cin>>v[i];
        mst2.insert(v[i]);
    }
    ll ans=0;
    for(ll i=0;i<n-1;i++){
        mst2.erase(mst2.find_by_order(mst2.order_of_key(v[i])));
        ll say1=mst1.order_of_key(v[i]);
        ll say2=mst2.order_of_key(v[i]);
        ans+=say1*say2;
        mst1.insert(v[i]);
    }
    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