Cod sursa(job #1447517)

Utilizator florinasAsavei florinas Data 4 iunie 2015 17:17:28
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.94 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

queue <int> Q;
vector <int> a[100005];
bool v[100005];
int C[100005];

int n, m, s;

inline void BFS()
{
    for (int i = 1; i <= n; i++)
        C[i] = -1;
    Q.push(s);
    C[s] = 0;
    v[s] = true;
    while (!Q.empty())
    {
        int nod = Q.front();
        Q.pop();
        int l = a[nod].size();
        for (int i = 0; i < l; i++)
            if (!v[a[nod][i]])
            {
                v[a[nod][i]] = true;
                C[a[nod][i]] = C[nod] + 1;
                Q.push(a[nod][i]);
            }
    }
}

int main()
{
    int i, x, y;
    fin >> n >> m >> s;
    for (i = 1; i <= m; i++)
    {
        fin >> x >> y;
        a[x].push_back(y);
    }
    BFS();
    for (i = 1; i <= n; i++)
        fout << C[i] << " ";
    return 0;
}