Cod sursa(job #2856970)

Utilizator norryna07Alexandru Norina norryna07 Data 24 februarie 2022 17:59:09
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.88 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

ifstream fin ("bfs.in");
ofstream fout ("bfs.out");

vector < vector <int> > g;
vector <int> lvl;
queue <int> q;
int n, m, st;

void citire()
{
    int x, y;
    fin>>n>>m>>st;
    g = vector < vector <int> > (n+2);
    lvl = vector <int> (n+2);
    for (int i=1; i<=m; ++i)
    {
        fin>>x>>y;
        g[x].push_back(y);
        //g[y].push_back(x);
    }
}

void bfs(int st)
{
    q.push(st);
    lvl[st]=1;
    while (!q.empty())
    {
        int x=q.front(); q.pop();
        for (auto y:g[x])
            if (!lvl[y])
            {
                lvl[y]=lvl[x]+1;
                q.push(y);
            }
    }
}

void afisare()
{
    for (int i=1; i<=n; ++i) fout<<lvl[i]-1<<' ';
}

int main()
{
    citire();
    bfs(st);
    afisare();
    return 0;
}