Cod sursa(job #590430)

Utilizator ukiandreaAndreea Lucau ukiandrea Data 17 mai 2011 13:05:04
Problema BFS - Parcurgere in latime Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 1.1 kb
#include <stdio.h>
#include <vector>
#include <utility>
#include <queue>
#include <map>

#define WHITE 1
#define GRAY  2
#define BLACK 3

std::map<int, int> visited;
std::vector<int> adj[100001];

void bfs(std::vector<int> *adj, int s)
{
    std::queue<int> q;

    q.push(s);
    visited[s] = 0;

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

        for (int i = 0; i < adj[node].size(); i++)
        {
            int child = adj[node][i];
            if (visited.find(child) == visited.end())
            {
                q.push(child);
                visited[child] = visited[node] + 1;
            }
        }
    }
}

int main()
{
    int m, n, s, i; 

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

    scanf("%d %d %d", &n, &m, &s);

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

    bfs(adj, s);

    for (i = 1; i <= n; i++)
    {
        if (visited.find(i) != visited.end())
            printf("%d ", visited[i]);
        else 
            printf("-1 ");
    }

    return 0;
}