Cod sursa(job #2173945)

Utilizator tifui.alexandruTifui Ioan Alexandru tifui.alexandru Data 16 martie 2018 09:48:20
Problema Componente tare conexe Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.89 kb
#include <bits/stdc++.h>
#define Nmax 100001
using namespace std;
ifstream f("ctc.in");
ofstream g("ctc.out");
list <int> G[Nmax];
list <int> Gt[Nmax];
int n,m,N;
int v[Nmax];
bitset <Nmax> viz;
list <int> ctc[Nmax];
void DFS1(int x)
{
    viz[x]=true;
    for(const auto &it:G[x])
        if(!viz[it]) DFS1(it);
    v[++N]=x;
}
void DFS2(int x)
{
    viz[x]=false;
    ctc[N].push_back(x);
    for(const auto &it:Gt[x])
        if(viz[it]) DFS2(it);
}
int main()
{
    int i,j;
    f>>n>>m;
    while(m--)
    {
        f>>i>>j;
        G[i].push_back(j);
        Gt[j].push_back(i);
    }
    for(i=1;i<=n;i++)
        if(!viz[i]) DFS1(i);
    N=0;
    for(i=n;i;i--)
        if(viz[v[i]])
        {
            ++N;
            DFS2(v[i]);
        }
    g<<N<<'\n';
    for(i=1;i<=N;i++,g<<'\n')
        for(const auto &it:ctc[i]) g<<it<<' ';

    return 0;
}