Cod sursa(job #2756011)

Utilizator razvan_tanaseTanase Razvan-Andrei razvan_tanase Data 29 mai 2021 08:49:27
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.97 kb
#include <bits/stdc++.h>
#include <fstream>
using namespace std;

const char iname[] = "bfs.in";
const char oname[] = "bfs.out";

#define INF (1 << 30)

int main() {
    ifstream in(iname);

    static constexpr int NMAX = (int)1e5 + 5;

    int N, M, S;
    in >> N >> M >> S;
    vector<int> adj[NMAX];

    for (int i = 1, x, y; i <= M; ++i) {
        in >> x >> y;
        adj[x].push_back(y);
    }
    in.close();

    vector<int> dist(N + 1, INF);
    queue<int> q;

    dist[S] = 0;
    q.push(S);

    while (!q.empty()) {
        int node = q.front();
        q.pop();

        for (auto& neigh : adj[node]) {
            int newDist = dist[node] + 1;
            if (newDist < dist[neigh]) {
                dist[neigh] = newDist;
                q.push(neigh);
            }
        }
    }

    ofstream out(oname);

    for (auto& value : dist) {
        if (value == INF) {
            value = -1;
        }

        out << value << ' ';
    }
    out.close();

    return 0;
}