Submission #1003422

#	Time	Username	Problem	Language	Result	Execution time	Memory
1003422		AtinaR	Mountains (NOI20_mountains)	C++17	100 / 100	682 ms	88176 KiB

Mountains

#include <bits/stdc++.h>

using namespace std;
#include <bits/extc++.h>
using namespace __gnu_pbds;
typedef tree<pair<long long,long long> , null_type, less<pair<long long,long long> >, rb_tree_tag, tree_order_statistics_node_update> ost;
const long long MOD=1e9+7;
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    ost tree,tree2;
    long long n;
    cin>>n;
    long long niza[n];
    for(long long i=0; i<n; i++)
    {
        cin>>niza[i];
    }
    long long l[n],r[n];
    map<long long,long long> mapa,mapa2;
    for(long long i=0; i<n; i++)
    {
        mapa[niza[i]]++;
        tree.insert({niza[i],mapa[niza[i]]});
        long long tmp=tree.order_of_key({niza[i],1});
        l[i]=tmp;
    }
    for(long long i=n-1; i>=0; i--)
    {
        mapa2[niza[i]]++;
        tree2.insert({niza[i],mapa2[niza[i]]});
        long long tmp=tree2.order_of_key({niza[i],1});
        r[i]=tmp;
    }
    long long res=0;
    for(long long i=0; i<n; i++)
    {
        res+=l[i]*r[i];
    }
    cout<<res<<endl;
    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