Submission #1173493

#	Time	Username	Problem	Language	Result	Execution time	Memory
1173493		qrn	Mountains (NOI20_mountains)	C++20	100 / 100	812 ms	21564 KiB

Mountains

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;

template<class T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define SPEED                     \
    ios_base::sync_with_stdio(0); \
    cin.tie(NULL);                \
    cout.tie(NULL);

#define pb push_back
#define ins insert
#define fi first
#define se second

#define endl "\n"
#define ALL(x) x.begin(), x.end()
#define sz(x) x.size()
#define intt long long

const intt mod = 1e9 + 7;
const intt base = 31;
const intt inf = 1e9;
const intt mxN = 1e3 + 5;
const intt L = 21;

void solve() {
    intt n;
    cin >> n;
    vector<intt> a(n);
    for(intt i = 0; i < n; i++) {
        cin >> a[i];
    }
    
    ordered_multiset<intt> mst, cmst;
    
    for(intt i = 1; i < n; i++) {
        mst.insert(a[i]);
    }
    
    cmst.insert(a[0]);
    intt ans = 0;
    for(intt i = 1; i < n - 1; i++) {
        mst.erase(mst.find_by_order(mst.order_of_key(a[i])));
        
        intt sol = cmst.order_of_key(a[i]);
        intt sag = mst.order_of_key(a[i]);
        ans += sol * sag;
        cmst.insert(a[i]);
        // cout << i << ": " << ans << endl;
    }
    cout << ans << endl;
}

signed main() {
    SPEED;
    intt tst = 1;
    // cin >> tst;
    while (tst--) {
        solve();
    }
}

• 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