Cod sursa(job #844123)

Utilizator silviuboganSilviu Bogan silviubogan Data 28 decembrie 2012 20:42:25
Problema BFS - Parcurgere in latime Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 0.95 kb
#include <queue>
#include <map>
#include <vector>

#include <cstring>
#include <cstdio>

using namespace std;

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

    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);

    scanf("%d %d %d", &n, &m, &s);
    for (i = 0; i < m; i++) {
        scanf("%d %d", &x, &y);
        g[x].push_back(y);
    }

    int t, itv, cost[n + 1];
    queue<int> Q;
    vector<int>::iterator endit, it;

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

    while (!Q.empty()) {
        t = Q.front();
        Q.pop();
        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++) {
        printf("%d ", cost[i]);
    }

    return 0;
}