Cod sursa(job #1795188)

Utilizator Zydrax04Morar Rares Zydrax04 Data 2 noiembrie 2016 07:54:34
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.99 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

ifstream fin ("bfs.in");
ofstream fout ("bfs.out");
vector <int> L[100005];
int n, m, d[100005], s, viz[100005];
queue <int> q;
void initializare()
{
    fin >> n >> m >> s;
    int x, y;
    for(int i=1;i<=m;i++)
    {
        fin >> x >> y;
        L[x].push_back(y);
    }
}

void BFS(int nod)
{
    viz[nod]=1;
    d[nod]=0;
    q.push(nod);
    while(!q.empty())
    {
        int val=q.front();
        q.pop();
        for(int i=0;i<L[val].size();i++)
        {
            int vecin=L[val][i];
            if(viz[vecin]==0)
            {
                q.push(vecin);
                d[vecin]=d[val]+1;
                viz[vecin]=1;
            }
        }
    }
}

int main()
{
    initializare();
    BFS(s);
    for(int i=1;i<=n;i++)
    {
        if(d[i]>0 || i==s)
            fout << d[i] << " ";
        else
            fout << "-1" << " ";
    }
    return 0;
}