Cod sursa(job #2150751)

Utilizator savigunFeleaga Dragos-George savigun Data 3 martie 2018 19:18:55
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.84 kb
#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

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

const int MAXN = 100005;
const int INF = 2e9;
int n, m, S, dist[MAXN];
int p, u, q[MAXN];
vector<int> g[MAXN];

int main()
{
    in >> n >> m >> S;
    for (int i = 1, x, y; i <= m; ++i) {
        in >> x >> y;
        g[x].push_back(y);
    }

    for (int i = 1; i <= n; ++i) dist[i] = INF;
    dist[S] = 0;

    q[0] = S;

    while (p <= u) {
        int x = q[p];
        p++;
        for (int y : g[x]) {
            if (dist[x] + 1 < dist[y]) {
                dist[y] = dist[x] + 1;
                q[++u] = y;
            }
        }
    }

    for (int i = 1; i <= n; ++i) {
        if (dist[i] == INF) out << -1 << " ";
        else out << dist[i] << " ";
    }


    return 0;
}