Cod sursa(job #1324178)

Utilizator dariusmareCostolas Darius dariusmare Data 21 ianuarie 2015 22:17:21
Problema BFS - Parcurgere in latime Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 1.27 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
int N,M,S;
vector <int> g[100002];
queue <int> vecini;
int vizitat[100002];
int cost[100002];
void Read()
{
    fin >> N>>M>>S;
    for(int i=0; i<M; i++)
    {
        int x,y;
        fin >> x>>y ;
        g[x].push_back(y);
    }
}
void Print()
{
    for(int i=1; i<=N; i++)
    {
        cout << "Lista lui " << i << ": ";
        for(unsigned int j=0; j<g[i].size(); j++)
            cout << g[i][j] << " ";
        cout << endl;
    }
}
void BFS()
{
    int nod = S;
    cost[nod] = 0;
    vecini.push(nod);
    while(!vecini.empty())
    {
        int actual = vecini.front();
        vizitat[actual] =1;
        vecini.pop();
        for(unsigned int i=0; i<g[actual].size(); i++)
            if(!vizitat[g[actual][i]])
            {
                vizitat[g[actual][i]] = 1;
                cost[g[actual][i]] = cost[actual] + 1;
                vecini.push(g[actual][i]);
            }
    }
    for(int i=1; i<=N; i++)
        fout << cost[i] << " ";
}
void init()
{
    for(int i=0; i<N; i++)
        cost[i] = -1;
}
int main()
{
    Read();
    init();
    BFS();
    return 0;
}