Cod sursa(job #1388746)

Utilizator zombacDica Razvan zombac Data 15 martie 2015 17:58:18
Problema Triplete Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.74 kb
#include <fstream>
#define BY 30
using namespace std;
ifstream fin ("triplete.in");
ofstream fout ("triplete.out");
int N, M, sol;
int x[66000], y[66000];
int V[4100][4100 / BY + 16];

int Get_Bits(int nr)
{
    int nr_bits = 0;
    while (nr)
    {
        if (nr & 1) nr_bits += 1;
        nr = (nr >> 1);
    }
    return nr_bits;
}

int main()
{
    fin >> N >> M;
    for (int i = 1; i <= M; i++)
    {
        fin >> x[i] >> y[i];
        if (x[i] > y[i]) swap(x[i], y[i]);
        V[x[i]][y[i] / BY] |= (1 << (y[i] % BY));
    }

    for (int i = 1; i <= M; i++)
    {
        for (int j = 0; j <= N / BY; j++)
        {
            sol += Get_Bits((V[x[i]][j] & V[y[i]][j]));
        }
    }

    fout << sol << '\n';
    fout.close();
    return 0;
}