Cod sursa(job #3224033)

Utilizator Dragono63Stanciu Rares Stefan Dragono63 Data 14 aprilie 2024 12:52:41
Problema P-sir Scor 60
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 2.62 kb
#ifndef LOCAL
    #pragma GCC optimize("O3")
    #pragma GCC target("avx2")
#endif

#ifdef LOCAL
    #define _GLIBCXX_DEBUG
#endif

#include <bits/stdc++.h>
#define int long long
#define pb push_back
#define pii pair<int, int>
using ll = long long;
using ci = const int;
using cll = const long long;

using namespace std;

const int MOD = (1LL << 32);
const int NMAX = 2e3 + 5;
/*******************************/
// INPUT / OUTPUT

#ifndef LOCAL
    ifstream in("psir.in");
    ofstream out("psir.out");
    #define cin in
    #define cout out
#endif
/*******************************/
/// GLOBAL DECLARATIONS

int N, M;
int sol;
int v[NMAX];
int aib[NMAX][NMAX];

inline void update(int care, int pos, int val)
{
    while (pos <= M)
    {
        aib[care][pos] += val;
        if (aib[care][pos] >= MOD) aib[care][pos] -= MOD;
        pos += (pos & (-pos));
    }
}

inline int query(int care, int pos)
{
    int suma = 0;
    while (pos)
    {
        suma += aib[care][pos];
        if (suma >= MOD) suma -= MOD;
        pos -= (pos & (-pos));
    }

    return suma;
}

vector <int> valori;
/*******************************/
/// FUNCTIONS

void ReadInput();
void Solution();
void Output();
/*******************************/
///-------------------------------------
inline void ReadInput()
{
    cin >> N;

    for (int i = 1 ; i <= N ; ++ i)
    {
        cin >> v[i];
        valori.push_back(v[i]);
    }
}
///-------------------------------------
inline int get_norm(int x)
{
    return lower_bound(valori.begin(), valori.end(), x) - valori.begin() + 1;
}
///-------------------------------------
inline void Solution()
{
    sort(valori.begin(), valori.end());
    valori.erase(unique(valori.begin(), valori.end()), valori.end());

    M = valori.size();

    int dp;
    for (int i = 1 ; i <= N ; ++ i)
    {
        for (int j = i + 1 ; j <= N ; ++ j)
        {
            dp = 1;
            if (v[i] > v[j])
            {
                dp += query(i, get_norm(v[j]) - 1);
            }
            else
            {
                if (v[i] < v[j])
                    dp += (query(i, valori.size()) - query(i, get_norm(v[j])));
            }

            if (dp < 0) dp += MOD;
            if (dp >= MOD) dp -= MOD;
            
            sol += dp;
            if (sol >= MOD) sol -= MOD;

            update(j, get_norm(v[i]), dp);
        }
    }
}
///-------------------------------------
inline void Output()
{
    cout << sol;
}
///-------------------------------------
signed main()
{
    #ifndef LOCAL
        ios::sync_with_stdio(false);
        cin.tie(NULL);
        cout.tie(NULL);
    #endif
    ReadInput();
    Solution();
    Output();
    return 0;
}