Cod sursa(job #1380386)

Utilizator tudoras8tudoras8 tudoras8 Data 7 martie 2015 17:36:16
Problema BFS - Parcurgere in latime Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <limits>

using namespace std;

#define MAXN 100010
#define MANM 1000010

enum Color { WHITE, GRAY, BLACK };

int n, m, s, d[MAXN], color[MAXN];
vector<int> adj[MAXN];
int inf = -1;

void bfs() {
    for (int i = 1; i <= n; i++) {
        color[i] = WHITE;
        d[i] = inf;
    }

    color[s] = GRAY;
    d[s] = 0;

    queue<int> q;
    q.push(s);

    while (!q.empty()) {
        int u = q.front();
        q.pop();

        for (int v : adj[u]) {
            if (color[v] == WHITE) {
                color[v] = GRAY;
                d[v] = d[u] + 1;
                q.push(v);
            }
        }
        color[u] = BLACK;
    }
}

int main()
{
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);
    cin >> n >> m >> s;
    for (int i = 0; i < m; i++) {
        int x, y;
        cin >> x >> y;
        adj[x].push_back(y);
    }
    bfs();
    for (int i = 1; i <= n; i++)
        cout << d[i] << ' ';
    return 0;
}