Cod sursa(job #214293)

Utilizator dragosmihaiDragos Oana dragosmihai Data 13 octombrie 2008 20:00:57
Problema Sortare topologica Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.8 kb
#include <iostream>
#include <vector>
#include <queue>
#include <fstream>
using namespace std;

int grad[100002];
queue<long> q;
vector<long> v[100002];
vector<long>::iterator it;
long n,m;

void topo()
{
    ofstream g("sortaret.out");
    for(int i=1;i<=n;i++)
        if(!grad[i]) q.push(i);
    while(!q.empty())
    {
        long z=q.front();
        g<<z<<" ";
        q.pop();
        for(it=v[z].begin();it!=v[z].end();it++)
        {
            grad[*it]--;
            if(grad[*it]==0) q.push(*it);
        }
    }
}

void citire()
{
    ifstream f("sortaret.in");
    f>>n>>m;
    for(int i=0;i<m;i++)
    {
        long a,b;
        f>>a>>b;
        grad[b]++;
        v[a].push_back(b);
    }
}

int main()
{
    citire();
    topo();
    return 0;
}