Cod sursa(job #1225444)

Utilizator roxana_97Soare Roxana Florentina roxana_97 Data 2 septembrie 2014 16:35:01
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include<fstream>
#include<vector>
#include<bitset>
#include<queue>
#define Nmax 100099
#define inf 2000000000
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
int n,m,x,y,d[Nmax],S;
vector <int> G[Nmax];
bitset <Nmax> viz;
queue <int> Q;
void BFS(int S){
    for(int i=1;i<=n;++i){
        d[i]=inf;
        //viz[i]=0;
    }
    d[S]=0;
    viz[S]=1;
    Q.push(S);
    while(!Q.empty()){
        int node=Q.front();
        Q.pop();
        vector <int> :: iterator it;
        for(it=G[node].begin();it!=G[node].end();++it){
            if(viz[*it]==0){
                viz[*it]=1;
                d[*it]=d[node]+1;
                Q.push(*it);
            }
        }
    }


}
int main()
{
    f>>n>>m>>S;
    for(int i=1;i<=m;i++){
        f>>x>>y;
        G[x].push_back(y);
        // graf neorientat G[y].push_back(x);
    }
   BFS(S);
   for(int i=1;i<=n;++i){
    if(d[i]==inf) g<<-1<<' ';
     else g<<d[i]<<' ';
   }
   g<<'\n';
    f.close();g.close();
    return 0;
}