Cod sursa(job #2718840)

Utilizator 21CalaDarius Calaianu 21Cala Data 9 martie 2021 11:40:45
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.01 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <cstring>
using namespace std;
ifstream fin ("bfs.in");
ofstream fout ("bfs.out");
vector <vector<int> > gr;
vector <int> d,g;
void BFS(int node)
{
    queue<int> q;
    q.push(node);
    for(int i=0;i<g.size();++i)
    {
        d[i]=-1;
    }
    d[node]=0;
    while(!q.empty())
    {
        int s=q.front();
        q.pop();
        for(int i=0;i<g[s];++i)
        {
            if(d[gr[s][i]]==-1)
            {
                q.push(gr[s][i]);
                d[gr[s][i]]=d[s]+1;
            }
        }
    }
}
int main()
{
    int n,m,s,x,y;
    fin >> n >> m >> s;
    gr.clear();
    gr.resize(n+1);
    g.resize(n+1);
    d.resize(n+1);
    for(int i=0;i<m;++i)
    {
        fin >> x >> y;
        gr[x].push_back(y);
    }
    for(int i=1;i<=n;++i)
    {
        g[i]=gr[i].size();
    }
    BFS(s);
    for(int i=0;i<n;++i)
    {
        cout << d[i] << " ";
    }
    return 0;
}