Cod sursa(job #1918749)

Utilizator tudormaximTudor Maxim tudormaxim Data 9 martie 2017 16:44:48
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
using namespace std;

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

const int maxn = 1e5 + 5;
vector <int> G[maxn];
int Dist[maxn];

void Bfs (int start, int n) {
    queue <int> Q;
    vector <int> :: iterator it;
    int node, i;
    for (i = 1; i <= n; i++) {
        Dist[i] = -1;
    }
    Dist[start] = 0;
    Q.push(start);
    while (!Q.empty()) {
        node = Q.front();
        Q.pop();
        for (it = G[node].begin(); it != G[node].end(); it++) {
            if (Dist[*it] == -1) {
                Dist[*it] = Dist[node] + 1;
                Q.push(*it);
            }
        }
    }
}

int main() {
    ios_base :: sync_with_stdio (false);
    int n, m, i, x, y, start;
    fin >> n >> m >> start;
    for (i = 1; i <= m; i++) {
        fin >> x >> y;
        G[x].push_back(y);
    }
    Bfs(start, n);
    for (i = 1; i <= n; i++) {
        fout << Dist[i] << " ";
    }
    return 0;
}