Cod sursa(job #2087249)

Utilizator StormieNerevarSarmasan SaSa StormieNerevar Data 13 decembrie 2017 10:44:39
Problema BFS - Parcurgere in latime Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 0.89 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

vector <int> G[100010];
queue <int> q;
int n,m,s,v[100010],d[100010];

void BFS(int nod)
{
    q.push(nod);
    v[nod]=1;
    d[nod]=0;
    q.push(nod);
    while(!q.empty())
    {
        int nod_actual=q.front();
        v[nod_actual]=1;
        q.pop();
        for(int i=0;i<G[nod_actual].size();i++)
            if(!v[G[nod_actual][i]])
        {
            q.push(G[nod_actual][i]);
            d[G[nod_actual][i]]=d[nod_actual]+1;
        }
    }
    for(int i=1;i<=n;i++)
        if(!v[i]) g<<-1<<' ';
        else g<<d[i]<<' ';
}

int main()
{
    f>>n>>m>>s;
    while(m--)
    {
        int a,b;
        f>>a>>b;
        G[a].push_back(b);
    }
    BFS(s);
    f.close();
    g.close();

    return 0;
}