Cod sursa(job #2900297)

Utilizator miruna_iliescuIliescu Miruna miruna_iliescu Data 10 mai 2022 18:42:22
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.18 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

const int N = 100000;

vector <int> a[N+1];
int d[N+1], n;

void init_d(int d[])
{
    for (int i = 1; i <= n; i++)
    {
        d[i] = -1;
    }
}

void bfs (int x0, int d[])
{
    init_d(d);
    queue <int> q;
    q.push(x0);
    d[x0] = 0;
    while (!q.empty())
    {
        int x = q.front();
        q.pop();
        for (auto y: a[x])///y va parcurge elementele lui a[x]
        {
            if (d[y] == -1)
            {
                q.push(y);
                d[y] = 1 + d[x];
            }
        }
    }
}

int main ()
{
    ifstream in("bfs.in");
    ofstream out("bfs.out");
    int m, s;
        in >> n >> m >> s;
    for (int i = 0; i < m; i++)
    {
        int x, y;
        in >> x >> y;
        //a[x][y] = a[y][x] = true;
        a[x].push_back(y);///il adauga pe y la sfarsitul listei de adiacenta a lui x (a[x])
        //a[y].push_back(x);///il adauga pe y in lista lui x
    }
    in.close();
    bfs(s,d);
    for (int i = 1; i <= n; i++)
    {
        out << d[i] << " ";
    }
    out.close();
    return 0;
}