Cod sursa(job #3229081)

Utilizator nistor_dora_valentinaNistor Dora Valentina nistor_dora_valentina Data 13 mai 2024 18:17:39
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.78 kb
#include <fstream>
#include <vector>
#include <queue>

using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
int n, m, s, i, x, y, nr, a[200005];
vector <int> v[200005];
queue <int> q;
void bfs(int nod)
{
    q.push(nod);
    a[nod]=1;
    while(!q.empty())
    {
        int x=q.front();
        for(auto i:v[x])
        {
            if(a[i]==0)
            {
                q.push(i);
                a[i]=a[x]+1;
            }

        }
        q.pop();
    }
}
int main()
{
    fin>>n>>m>>s;
    for(i=1; i<=m; i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
    }
    bfs(s);
    for(i=1; i<=n; i++)
        if(a[i]==0 && i!=s)
            fout<<-1<<" ";
        else
            fout<<a[i]-1<<" ";
    return 0;
}