Cod sursa(job #2867721)

Utilizator TeoRoGaming_YgVoinea Ionut-Florin TeoRoGaming_Yg Data 10 martie 2022 15:22:04
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.85 kb
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

ifstream f ("bfs.in");
ofstream g ("bfs.out");

const int N = 1e5 + 1;
vector <int> a[N];

int n, m, s, d[N];
queue <int> q;

void citire ()
{
    int i;
    f >> n >> m >> s;
    for (i=0; i<m; i++)
    {
        int x, y;
        f >> x >> y;
        a[x].push_back(y);
    }
    f.close();
}
void BFS()
{
    while (!q.empty())
    {
        int x = q.front();
        q.pop();
        for (auto y: a[x])
        {
            if (d[y] == -1)
            {
                q.push(y);
                d[y] = 1 + d[x];
            }
        }
    }
}
int main()
{
    int i;
    citire();
    for (i=1; i<=n; i++)
        d[i] = -1;
    q.push(s);
    d[s] = 0;
    BFS();
    for (i=1; i<=n; i++)
        g << d[i] << " ";
    return 0;
}