Cod sursa(job #2651313)

Utilizator Mihai_EduardMihai Eduard Mihai_Eduard Data 22 septembrie 2020 10:43:23
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.08 kb
#include <iostream>
#include <fstream>
#include <queue>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
struct nod
{
    int info;
    nod *urm;
};
nod *L[100001];
int n, m, s, fr[100001];
void adauga(int i, int j)
{
    nod *p=new nod;
    p->info=j;
    p->urm=L[i];
    L[i]=p;
}
void citire()
{
    fin>>n>>m>>s;
    int i, j;
    for(int k=1;k<=m;k++)
    {
        fin>>i>>j;
        adauga(i,j);
    }
    fin.close();
}
void parcurgereBFS(int poz)
{
    queue <int> C;
    C.push(poz);
    fr[poz]=1;
    while(!C.empty())
    {
        int q=C.front();
        C.pop();
        for(nod *p=L[q];p!=NULL;p=p->urm)
        {
            if(fr[p->info]==0)
            {
                fr[p->info]=fr[q]+1;
                C.push(p->info);
            }
        }
    }
}
int main()
{
    citire();
    parcurgereBFS(s);
    for(int i=1;i<=n;i++)
    {
        if(i==s)
            fout<<0<<' ';
        else if(fr[i]==0)
            fout<<-1<<' ';
        else
            fout<<fr[i]-1<<' ';
    }
    return 0;
}