Cod sursa(job #844112)

Utilizator silviuboganSilviu Bogan silviubogan Data 28 decembrie 2012 20:31:28
Problema BFS - Parcurgere in latime Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include <fstream>
#include <queue>
#include <map>
#include <vector>
#include <cstring>
using namespace std;

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

inline void bfs(map<int, vector<int> > g, int n, int i) {
    int t, itv, cost[n + 1];
    queue<int> Q;

    memset(cost, -1, sizeof(cost));
    Q.push(i);
    cost[i] = 0;

    while (!Q.empty()) {
        t = Q.front();
        Q.pop();
        vector<int>::iterator endit, it;
        for (it = g[t].begin(), endit = g[t].end(); it != endit; ++it) {
            itv = *it;
            if (cost[itv] == -1) {
                Q.push(itv);
                cost[itv] = cost[t] + 1;
            }
        }
    }

    for (i = 1; i <= n; i++) {
        out << cost[i] << ' ';
    }
}

int main()
{
    int n, m, s, i, x, y;
    map<int, vector<int> > g;

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

    bfs(g, n, s);

    in.close();
    out.close();

    return 0;
}