Cod sursa(job #1412309)

Utilizator rares96cheseliRares Cheseli rares96cheseli Data 1 aprilie 2015 11:20:03
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.75 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");

int N, M, x, y, S, D[100005];
vector <int> G[100005];
queue < int > Q;

void bfs(int sursa)
{
    for (int i=1; i<=N; ++i)
        D[i]=-1;
    Q.push(sursa); D[sursa]=0;

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

int main()
{
    f>>N>>M>>S;
    for (int i=1; i<=M; ++i)
    {
        f>>x>>y;
        G[x].emplace_back(y);
    }

    bfs(S);
    for (int i=1; i<=N; ++i)
        g<<D[i]<<' ';
    return 0;
}