Cod sursa(job #1415587)

Utilizator CiobraNume Prenume Ciobra Data 5 aprilie 2015 11:55:46
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.91 kb
#include <iostream>
#include <queue>
#include <vector>
#include <cstdio>
#include <fstream>
#include <cstring>

using namespace std;

int cost[100005];
vector <int> v[100005];

int n, m, s, x, y;

void bfs(int node) {
    memset(cost, -1, sizeof(cost));
    queue <int> q;
    q.push(node);
    cost[node] = 0;
    while (!q.empty()) {
        node = q.front();
        q.pop();
        for (int i = 0; i < v[node].size(); ++i)
            if (cost[v[node][i]] == -1) {
                q.push(v[node][i]);
                cost[v[node][i]] = cost[node] + 1;
            }
    }
}

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

    f >> n >> m >> s;
    for (int i = 0; i < m; ++i) {
        f >> x >> y;
        v[x].push_back(y);
    }

    bfs(s);

    for (int i = 1; i <= n; i++)
        g << cost[i] << " ";

    f.close();
    g.close();
    return 0;
}