Cod sursa(job #605015)

Utilizator SpiderManSimoiu Robert SpiderMan Data 26 iulie 2011 16:13:34
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.88 kb
# include <cstdio>
# include <cstring>
# include <queue>
# include <vector>
using namespace std;

const char *FIN = "bfs.in", *FOU = "bfs.out";
const int MAX = 100005;

vector <int> G[MAX];
int N, M, S, dp[MAX];

void bfs (int S) {
    memset (dp, -1, sizeof (dp)), dp[S] = 0;
    queue <int> Q;
    for (Q.push (S); !Q.empty (); Q.pop ()) {
        int X = Q.front ();
        for (vector <int> :: iterator i = G[X].begin (); i != G[X].end (); ++i)
            if (dp[*i] == -1) {
                Q.push (*i), dp[*i] = dp[X] + 1;
            }
    }
}

int main (void) {
    freopen (FIN, "r", stdin);
    freopen (FOU, "w", stdout);

    scanf ("%d %d %d", &N, &M, &S);
    for (int i = 1, x, y; i <= M; ++i) {
        scanf ("%d %d", &x, &y);
        G[x].push_back (y);
    }
    bfs (S);
    for (int i = 1; i <= N; ++i)
        printf ("%d ", dp[i]);
}