Cod sursa(job #1803208)

Utilizator BogdanNeghinaNeghina Bogdan BogdanNeghina Data 11 noiembrie 2016 09:25:38
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
vector <int> v[100005];
int n,m,S,viz[100005],d[100005];
void citire ()
{
    int a,b;
   fin>>n>>m>>S;
    for(int i=1;i<=m;i++)
    {
        fin>>a>>b;

        v[a].push_back(b);
    }
}

void bfs ()
{
    int x;
    queue <int> c;
    c.push(S);
    viz[S]=1;
    d[S]=0;
    while(!c.empty())
    {
        x=c.front();
        c.pop();
        for(int i=0;i<v[x].size();i++)
        {
            if(viz[v[x][i]]==0)
            {
                c.push(v[x][i]);
                viz[v[x][i]]=1;
                d[v[x][i]]=d[x]+1;
            }
        }
    }
}
int main()
{
    citire();

    bfs();
    for(int i=1;i<=n;i++)
    {
        if(d[i]==0)
        {
            if(i==S)
                fout<<0<<" ";
            else
                fout<<-1<<" ";
        }
        else
            fout<<d[i]<<" ";
    }
    return 0;
}