Cod sursa(job #984573)

Utilizator alex_HarryBabalau Alexandru alex_Harry Data 14 august 2013 20:01:27
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.85 kb
#include <fstream>
#include <vector>
#include <queue>
#include <cstring>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
int N,M,S;
int D[100002];
vector <int> G[100002];
queue <int> Q;
void Read()
{
    f>>N>>M>>S;
    int i;
    for(i=1;i<=M;i++)
    {
        int x,y;
        f>>x>>y;
        G[x].push_back(y);
    }
}
void BFS()
{
    memset(D,-1,sizeof(D));
    Q.push(S);
    D[S]=0;
    while(!Q.empty())
    {
        int nod=Q.front();Q.pop();
        for(unsigned int j=0;j<G[nod].size();j++)
            if(D[G[nod][j]]==-1)
            {
                Q.push(G[nod][j]);
                D[G[nod][j]]=D[nod]+1;
            }
    }
}
void Print()
{
    int i;
    for(i=1;i<=N;i++)
        g<<D[i]<<" ";
    g<<"\n";
}
int main()
{
    Read();
    BFS();
    Print();
    return 0;
}