Cod sursa(job #1012086)

Utilizator lucianRRuscanu Lucian lucianR Data 17 octombrie 2013 23:49:37
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.97 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define M_MAX 1000001
#define N_MAX 100001

using namespace std;
ifstream in("bfs.in");
ofstream out("bfs.out");

queue <int> q;
vector <int> graph[N_MAX];
int n, m, start, d[N_MAX];

void BFS(int node)
{
    for(int i = 1; i <= n; i++)
        d[i] = -1;
    d[start] = 0;
    q.push(start);
    while(!q.empty())
    {
        int x = q.front();
        q.pop();
        for(int i = 0; i < graph[x].size(); i++)
        {
            if(d[graph[x][i]] == -1)
            {
                q.push(graph[x][i]);
                d[graph[x][i]] = d[x] + 1;
            }
        }
    }
}

int main()
{
    in >> n >> m >> start;
    int x, y;
    for(int i = 0; i < m; i++)
    {
        in >> x >> y;
        graph[x].push_back(y);
    }
    BFS(start);
    for(int i = 1; i <= n; i++)
        out << d[i] << " ";
    in.close();
    out.close();
    return 0;
}