Cod sursa(job #2872837)

Utilizator shutdownRadu Dumitrache shutdown Data 17 martie 2022 21:29:22
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.89 kb
#include <fstream>
#include <queue>
#include <vector>
#define inf 1<<19
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
vector <int> v[100001];
queue <int> q;

int n,m,st,d[100001];
void bfs(int st)
{
    q.push(st);
    d[st]=1;

    while (!q.empty())
    {
        int nod=q.front();
        q.pop();
        for (vector <int> ::iterator it=v[nod].begin();it!=v[nod].end();it++)
        {
            if (d[(*it)]==0)
            {
                d[(*it)]=d[nod]+1;
                q.push(*it);
            }

        }


    }
}

int main()
{
    fin>>n>>m>>st;
    for (int i=1;i<=m;i++)
    {
        int x,y;
        fin>>x>>y;
        v[x].push_back(y);

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