Cod sursa(job #2440563)

Utilizator Dobricean_IoanDobricean Ionut Dobricean_Ioan Data 18 iulie 2019 18:21:08
Problema P-sir Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.09 kb
#include <fstream>
#include <map>

using namespace std;

ifstream fin ("psir.in");
ofstream fout ("psir.out");

typedef unsigned int u32;

const int nmax = 2000;
u32 s[nmax + 1][nmax + 1];

int n;
int v[nmax + 1];
map< int, int > mp;

void citire_si_norm () {
    fin >> n;
    for (int i = 1; i <= n; ++ i) {
        fin >> v[i];
        mp[v[i]] = 1;
    }

    int ind = 0;
    for (auto &i : mp) {
        i.second = ++ ind;
    }

    for (int i = 1; i <= n; ++ i) {
        v[i] = mp[v[i]];
    }
}

int main () {
    citire_si_norm ();

    u32 ans = 0;
    for (int i = 1; i <= n; ++ i) {
        for (int j = 1; j < i; ++ j) {
            u32 d = 1;

            if (v[i] > v[j]) {
                d += s[j][n] - s[j][v[i]];
            } else if (v[i] < v[j]) {
                d += s[j][v[i] - 1];
            }

            s[i][v[j]] += d;
        }

        for (int j = 1; j <= n; ++ j) {
            s[i][j] += s[i][j - 1];
        }
        ans += s[i][n];
    }

    fout << ans << "\n";

    fin.close();
    fout.close();
    return 0;
}