Cod sursa(job #1325091)

Utilizator hopingsteamMatraguna Mihai-Alexandru hopingsteam Data 23 ianuarie 2015 11:19:44
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.12 kb
/*
    Rescriere OLI 2015
    Start: 10:45
*/

#include    <iostream>
#include    <fstream>
#include    <vector>
#include    <queue>

using namespace std;

ifstream fin("bfs.in");
ofstream fout("bfs.out");

const int NLIM = 100005;

vector  < int > V[NLIM];
queue   < int > Q;

int N, M, S;
int Distance[NLIM];

void BFS()
{
    int Node, Next;
    while(!Q.empty())
    {
        Node = Q.front();
        for(unsigned int i = 0; i < V[Node].size(); i++)
        {
            Next = V[Node][i];
            if(Distance[Next] == -1)
            {
                Q.push(Next);
                Distance[Next] = Distance[Node] + 1;
            }
        }
        Q.pop();
    }
}

void Read()
{
    fin >> N >> M >> S;

    int x, y;
    for(int i = 1; i <= M; i++)
    {
        fin >> x >> y;
        V[x].push_back(y);
    }

    for(int i = 1; i <= N; i++)
        Distance[i] = -1;
    Distance[S] = 0;

    Q.push(S);
}

void Show()
{
    for(int i = 1; i <= N; i++)
        fout << Distance[i] << " ";
}

int main()
{
    Read();
    BFS();
    Show();
    return 0;
}