Submission #894613

#	Time	Username	Problem	Language	Result	Execution time	Memory
894613		IWKR	Mountains (NOI20_mountains)	C++17	100 / 100	703 ms	48416 KiB

Mountains

#include <bits/stdc++.h>
#include <bits/extc++.h>
using namespace std;
using namespace __gnu_pbds;

#define int long long

template <typename T>
using pbds_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    pbds_set<int> s;
    pbds_set<int> t;
    int n;
    cin >> n;
    int arr[n];
    cin >> arr[0];
    s.insert(arr[0]);
    int demon[n];
    demon[0] = 0;
    int ans = 0;
    for (int i = 1; i < n; i++) {
        cin >> arr[i];
        demon[i] = s.order_of_key(arr[i]);
        s.insert(arr[i]);
    }
    t.insert(arr[n - 1]);
    for (int i = n - 2; i >= 0; i--) {
        int a = t.order_of_key(arr[i]);
        ans += demon[i] * a;
        t.insert(arr[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