Cod sursa(job #1436298)

Utilizator GeorgianaMMirlogeanu Georgiana GeorgianaM Data 15 mai 2015 18:29:39
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.93 kb
#include <fstream>
#include <vector>
#include <queue>
#include <bitset>

#define NMAX 100001
using namespace std;

ifstream f("bfs.in");
ofstream g("bfs.out");

vector <int> G[NMAX];
queue <int> Q;
bitset <NMAX> viz;
int cost [NMAX];

void BFS(int nod)
{
    while(!Q.empty())
    {
        nod=Q.front();
        for(unsigned int i=0; i<G[nod].size(); i++)
        {
            if(viz[G[nod][i]]==0)
            {
                cost[G[nod][i]]=cost[nod]+1;
                Q.push(G[nod][i]);
                viz[G[nod][i]]=1;
            }
        }
        Q.pop();
    }
}

int main()
{
    int i,N,M,S,x,y;
    f>>N>>M>>S;
    for(i=1; i<=M; i++)
    {
        f>>x>>y;
        G[x].push_back(y);
    }
    Q.push(S);
    viz[S]=1;
    cost[S]=0;
    BFS(S);
    for(i=1; i<=N; i++)
        if(viz[i]==1)
            g<<cost[i]<<" ";
        else
            g<<-1<<" ";
    return 0;
}