Cod sursa(job #2034210)

Utilizator AndreiTurcasTurcas Andrei AndreiTurcas Data 7 octombrie 2017 16:39:26
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.84 kb
#include <iostream>
#include <queue>
#include <vector>
#include <fstream>
#define lim 100002

using namespace std;

queue <int> Q;
vector <int> G[lim], D;
int n, m, S;
ifstream f("bfs.in");
ofstream g("bfs.out");
void Read()
{
    f >> n >> m >> S;
    D.resize(n+1, -1);
        int x, y;
    for(; m; --m)
    {
        f >> x >> y;
        G[x].push_back(y);
    }
}

void Read_Out()
{
    for(int i = 1; i <= n; ++i)
        g << D[i] << " ";
}

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

int main()
{
    Read();
    D[S] = 0;
    Q.push(S);
    BFS();
    Read_Out();
}