Cod sursa(job #2124421)

Utilizator calin1Serban Calin calin1 Data 7 februarie 2018 10:58:32
Problema Sortare topologica Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.58 kb
#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#include <stack>
#include <bitset>
#define N 50005

using namespace std;

int n,m,grad[N];

vector <int> G[N];

queue <int> q;

bitset <N> viz;

stack <int> s;

void sort_bfs()
{
    for(int i=1; i<=n; i++)
    {
        if(!grad[i])
        {
             q.push(i);
        }
    }

    while(!q.empty())
    {
        int tmp=q.front();

        printf("%d ",tmp);

        q.pop();

        vector<int>::iterator it;

        for(it=G[tmp].begin(); it<G[tmp].end(); ++it)
        {
            grad[*it]--;
            if(!grad[*it])
            {
                q.push(*it);
            }
        }
    }
}

void afis_stk()
{
    while(!s.empty())
    {
        printf("%d ",s.top());
        s.pop();
    }
}

void sort_dfs(int k)
{
    vector<int>::iterator it;

    for(it=G[k].begin(); it!=G[k].end(); ++it)
    {
        if(!viz[*it])
        {
            viz[*it]=1;
            sort_dfs(*it);
        }
    }
    s.push(k);
}

void dfs()
{
    for(int i=1; i<=n; i++)
    {
        if(!viz[i])
        {
            viz[i]=1;
            sort_dfs(i);
        }
    }
    afis_stk();
}

void citire()
{
    scanf("%d %d\n",&n,&m);

    for(int i=0; i<m; i++)
    {
        int x,y;
        scanf("%d %d\n",&x,&y);

        G[x].push_back(y);
        grad[y]++;
    }

    //sort_bfs();
    dfs();
}

int main()
{
    freopen("sortaret.in","r",stdin);
    freopen("sortaret.out","w",stdout);

    citire();

    return 0;
}