Cod sursa(job #855883)

Utilizator enedumitruene dumitru enedumitru Data 15 ianuarie 2013 19:23:57
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.73 kb
#include <fstream>
#include <vector>
#include <queue>
#define Nmax 100010
using namespace std;
ifstream f("bfs.in"); ofstream g("bfs.out");
int N,M,S;
vector <int> L[Nmax];
int Viz[Nmax];
queue <int> Q;
void BFS(int nod)
{   Q.push(nod); Viz[nod]=0;
    while(!Q.empty())
    {   nod=Q.front(); Q.pop();
        vector<int>::iterator it=L[nod].begin(), sf=L[nod].end();
        for(; it!=sf; ++it)
            if(Viz[*it]==-1)
                {Q.push(*it); Viz[*it]=Viz[nod]+1;}
    }
}
int main()
{   f>>N>>M>>S;
    for(int i=1;i<=N;i++) Viz[i]=-1;
    for(int x, y, i=1; i<=M; ++i)
        f>>x>>y, L[x].push_back(y);
    BFS(S);
    for(int i=1; i<=N; ++i) g<<Viz[i]<<' ';
    g<<'\n'; g.close();
    return 0;
}