Cod sursa(job #617272)

Utilizator theocmtAxenie Theodor theocmt Data 14 octombrie 2011 14:41:13
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.82 kb
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

int n,m,s,d[100001],x,y;
vector <int> a[100001];
queue <int> q;

void citire()
{
    ifstream in("bfs.in");
    int x,y;
    in >> n >> m >> s;
    for (int i=1; i<=n; ++i)
        d[i]=-1;
    while (m--)
    {
        in >> x >> y;
        a[x].push_back(y);
    }
}

int main()
{
    int i;

    ofstream out("bfs.out");

    citire();

    d[s]=0;
    q.push(s);

    while (!q.empty())
    {
        x=q.front();
        q.pop();
        for (i=0; i<a[x].size(); ++i)
        {
            y=a[x][i];
            if(d[y] == -1)
            {
                q.push(y);
                d[y]=1+d[x];
            }
        }
    }

    for (i=1; i<=n; ++i)
        out << d[i] << " ";

    return 0;
}