Submission #1137022

#	Time	Username	Problem	Language	Result	Execution time	Memory
1137022		TheInvadr	Mountains (NOI20_mountains)	C++20	100 / 100	771 ms	21548 KiB

Mountains

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

int main()
{
    int n;
    cin>>n;
    long long int arr[n];
    ordered_multiset<long long int> left;
    ordered_multiset<long long int> right;
    for(int i =0;i<n;i++){
        cin>>arr[i];
        right.insert(arr[i]);
    }
    long long int cnt = 0;
    for(int i =0;i<n;i++){
        long long int l = left.order_of_key(arr[i]);
        long long int r = right.order_of_key(arr[i]);
        cnt+=l*r;
        left.insert(arr[i]);
        right.erase(right.find_by_order(right.order_of_key(arr[i])));
    }
    cout<<cnt;
}

• 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