Cod sursa(job #1647336)

Utilizator jeronimoPopovici Daniel jeronimo Data 10 martie 2016 20:04:02
Problema Sortare topologica Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.3 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <stack>

using namespace std;

ifstream f("sortaret.in");
ofstream g("sortaret.out");
vector<vector<int> > graf;
vector<bool> visited;
stack<int> sortat;
int n,m;

void sortaret(int x)
{
    int i;
    if(x<0 || x>n-1)
        return;
    stack<int> s;
    int element;
    bool found;
    s.push(x);
    visited[x]=true;
    while(!s.empty())
    {
        element=s.top();
        found=false;
        for(i=0; i<graf[element].size() && !found; i++)
        {
            if(!visited[graf[element][i]])
                found=true;
        }
        if(found)
        {
            i--;
            s.push(graf[element][i]);
            visited[graf[element][i]]=true;
        }
        else
        {
            sortat.push(element);
            s.pop();
        }
    }


}

int main()
{
    int i,x,y;
    f>>n>>m;
    graf.resize(n);
    visited.resize(n,false);
    for(i=0; i<m; i++)
    {
        f>>x>>y;
        x--;
        y--;
        graf[x].push_back(y);
    }
    for(i=0; i<visited.size() && i<n; i++)
        if(!visited[i])
            sortaret(i);
    while(!sortat.empty())
    {
        g<<sortat.top()+1<<" ";
        sortat.pop();
    }
    g.close();
    return 0;

}