Submission #1311004

#	Time	Username	Problem	Language	Result	Execution time	Memory
1311004		discontinuous	Mountains (NOI20_mountains)	C++20	2 / 100	290 ms	32436 KiB

Mountains

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace __gnu_pbds;
using namespace std;

#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>

#define pb push_back
#define int long long

const int MOD = 1e9 + 7;
const int INF = 1e15;
const int N = 1e6;

int n, m, k, a, b, c, d, h, l, r, q, u, v, x, y;
vector<int> arr(N);

void solve() {
	cin >> n;

	for(int i = 0; i<n; i++) {
		cin >> arr[i];
	}

	ordered_set all;
	all.insert(arr[0]);

	vector<int> smaller(n);
	vector<int> bigger(n);

	for(int i = 1; i<n; i++) {
		smaller[i] = all.order_of_key(arr[i]);
		all.insert(arr[i]);
	}

	all.clear();
	all.insert(arr[n-1]);
	for(int i = n-2; i>=0; i--) {
		bigger[i] = all.order_of_key(arr[i]);
		all.insert(arr[i]);
	}

	c = 0;
	for(int i = 1; i<n-1; i++) c += smaller[i]*bigger[i];
	cout << c;
}

int32_t main() {
    ios::sync_with_stdio(false);
    cout.tie(0); cin.tie(0);

	int tc = 1;
	// cin >> tc;

	while(tc--) {
		solve();
		cout << "\n";
	}

	return 0;
}

• Subtask 1: 2 / 2
• Subtask 2: 0 / 4
• Subtask 3: 0 / 9
• Subtask 4: 0 / 36
• Subtask 5: 0 / 28
• Subtask 6: 0 / 9
• Subtask 7: 0 / 12