Cod sursa(job #2034190)

Utilizator AndreiTurcasTurcas Andrei AndreiTurcas Data 7 octombrie 2017 16:12:51
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1 kb
#include <iostream>
#include <set>
#include <queue>
#include <vector>
#define lim 100002
#define INF 0x3f3f3f3f

using namespace std;

queue <int> Q;
set <int> G[lim];
vector <int> D;
int n, m, S;

void Read()
{
    cin >> n >> m >> S;
    D.resize(n+1, INF);
        int x, y;
    for(; m; --m)
    {
        cin >> x >> y;
        G[x].insert(y);
    }
}

void Read_Out()
{
    for(int i = 1; i < D.size(); ++i)
        if(D[i] == INF) cout << -1 << " ";
    else
        cout << D[i] << " ";
}

void BFS()
{
    while(!Q.empty())
    {
        int F = Q.front();
        Q.pop();
    for(set <int> :: iterator it = G[F].begin(); it != G[F].end(); ++it)
        if(D[*it] == INF)
        {
            cout << F << " " << *it << endl;
        D[*it] = D[F] + 1;
        Q.push(*it);
        }
    }
}

int main()
{
    freopen("bfs.in" , "r", stdin);
    freopen("bfs.out", "w", stdout);
    Read();
    D[S] = 0;
    Q.push(S);
    BFS();
    Read_Out();
}