Submission #285478

#	Time	Username	Problem	Language	Result	Execution time	Memory
285478		achibasadzishvili	Mountains (NOI20_mountains)	C++14	100 / 100	1213 ms	24184 KiB

Mountains

#include <bits/stdc++.h>
#define ll long long
#define f first
#define s second
#define pb push_back
#define mp make_pair
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<pair<long long,long long>, null_type,less<pair<long long,long long> >, rb_tree_tag,tree_order_statistics_node_update>
ll n,ans,a[300005],k[300005];
int main(){
    ordered_set st;
    cin >> n;
    for(int i=1; i<=n; i++){
        cin >> a[i];
        k[i] = st.order_of_key(mp(a[i],-1));
        st.insert(mp(a[i],i));
    }
    st.clear();
    for(int i=n; i>=1; i--){
        k[i] *= st.order_of_key(mp(a[i],-1));
        st.insert(mp(a[i],i));
        ans += k[i];
    }
    cout << ans << '\n';
    
    return 0;
}

• 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