Cod sursa(job #7923)

Utilizator ZeusCatalin Tiseanu Zeus Data 22 ianuarie 2007 23:45:07
Problema Triplete Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.61 kb

using namespace std;

#include <bitset>
#include <cstdio>

int N, M, E[65536][2];
bitset<4096> bs[4096];

int main()
{
    freopen("triplete.in", "r", stdin);
    freopen("triplete.out", "w", stdout);
    
    int x, y, ret(0);
    
    scanf("%d %d", &N, &M);
    
    for( int i = 0; i < M; i++ )
    {
         scanf("%d %d", &x, &y);
         --x, --y;
         bs[x][y] = bs[y][x] = 1;
         E[i][0] = x, E[i][1] = y;
    }
    
    for( int i = 0; i < M; i++ )
             ret += ( bs[ E[i][0] ] & bs[ E[i][1] ] ).count();     
    
    printf("%d\n", ret/3);
    
    return 0;
}