Cod sursa(job #999372)

Utilizator manutrutaEmanuel Truta manutruta Data 19 septembrie 2013 23:43:37
Problema Componente tare conexe Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.47 kb
# include <iostream>
# include <fstream>
# include <vector>
# include <bitset>
using namespace std;

# define MAXN 100010

typedef vector<int>::iterator iter;
typedef vector<int>::reverse_iterator riter;

ifstream f("ctc.in");
ofstream g("ctc.out");

int n, m;
vector<int> G[MAXN], Gt[MAXN];
vector<int> order;
bitset<MAXN> viz;
vector<int> comp;
vector< vector<int> > comps;

void topo(int i)
{
    if (viz[i]) {
        return;
    }
    viz[i] = true;

    for (iter it = G[i].begin(); it != G[i].end(); ++it) {
        topo(*it);
    }

    order.push_back(i);
}

void conex(int i)
{
    if (viz[i]) {
        return;
    }
    viz[i] = true;

    comp.push_back(i);
    for (iter it = Gt[i].begin(); it != Gt[i].end(); it++) {
        conex(*it);
    }
}

int main()
{
    f >> n >> m;
    for (int i = 1; i <= m; i++) {
        int x, y;
        f >> x >> y;
        G[x].push_back(y);
        Gt[y].push_back(x);
    }

    for (int i = 1; i <= n; i++) {
        topo(i);
    }

    viz.reset();
    for (riter it = order.rbegin(); it != order.rend(); it++) {
        if (!viz[*it]) {
            conex(*it);
            comps.push_back(comp);
            comp.clear();
        }
    }

    for (int i = 0; i < comps.size(); i++) {
        for (iter it = comps[i].begin(); it != comps[i].end(); it++) {
            g << *it << ' ';
        }
        g << '\n';
    }

    f.close();
    g.close();
    return 0;
}