Cod sursa(job #984239)

Utilizator rogoz.bogdanRogoz Bogdan rogoz.bogdan Data 13 august 2013 21:06:48
Problema BFS - Parcurgere in latime Scor 60
Compilator cpp Status done
Runda Arhiva educationala Marime 0.96 kb
#include <fstream>
#include <vector>
using namespace std;

fstream fin("bfs.in", ios::in);
fstream fout("bfs.out", ios::out);

long long N,M,S;

vector <int> A[100010];

bool viz[100010];
long dist[100010];

long c[100010],p,u;

void BFS()
{
    long t,z;

    while(p<=u)
    {
        t=c[p];
        p++;
        viz[t]=1;
        while(A[t].size() > 0 )
        {
            z=A[t].size();

            if(viz[A[t][z-1]] == 0) { c[++u]=A[t][z-1]; dist[c[u]] = dist[t] + 1;}
            viz[c[u]] = 1;

            A[t].pop_back();
        }
    }
}

int main()
{
    fin>>N>>M>>S;
    long long i,x,y;
    for(i=1; i<=M; i++)
    {
        fin>>x>>y;
        A[x].push_back(y);
    }


    for(i=1; i<=M; i++)
    {
        dist[i]=-1;
    }

    dist[S]=0;

    p=1; u=1; c[u]=S;

    BFS();

    for(i=1; i<=N; i++)
    {
        fout<<dist[i]<<' ';
    }

    fin.close(); fout.close();
    return 0;
}