Cod sursa(job #1791889)

Utilizator LaurIleIle Laurentiu Daniel LaurIle Data 29 octombrie 2016 20:13:08
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

int n, m, s;
vector <vector <int> > G(100002);
queue <int> q;
vector <bool> viz(100002, 0);
vector <int> dmin(100002, -1);

void read()
{
    ifstream f("bfs.in");
    f >> n >> m >> s;
    for(int i=0, x, y; i<m; ++i)
    {
        f >> x >> y;
        G[x].push_back(y);
    }
    f.close();
}

void bfs(int s)
{
    int x;
    dmin[s]=0;
    viz[s]=1;
    q.push(s);
    while(!q.empty())
    {
        x=q.front(); q.pop();
        for(int i=0; i<G[x].size(); ++i)
        {
            if(!viz[G[x][i]])
            {
                q.push(G[x][i]);
                viz[G[x][i]]=1;
                dmin[G[x][i]]=dmin[x]+1;
            }
        }
    }
}

void out()
{
    ofstream g("bfs.out");
    for(int i=1; i<=n; ++i)
    {
        g << dmin[i] << ' ';
    }
    g << '\n';
    g.close();
}

int main()
{
    read();
    bfs(s);
    out();
    return 0;
}