Cod sursa(job #1842856)

Utilizator remus88Neatu Remus Mihai remus88 Data 7 ianuarie 2017 17:56:16
Problema BFS - Parcurgere in latime Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 0.83 kb
#include <fstream>
#include <vector>
#include <bitset>
#include <queue>
#define Nmax 100009

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

int n,m,s,x,y,sol,cost[Nmax];
bitset <Nmax> viz;
vector <int> G[Nmax],cc;
queue <int> q;

void Bfs(int node, vector<int>& v)
{
    q.pop();
    v.push_back(node);
    viz[node]=1;
    for (auto x : G[node])
        if (!viz[x])
        {
            q.push(x);
            cost[x]=cost[node]+1;
        }
}

int main()
{
    f>>n>>m>>s;
    for (int i=1; i<=m; ++i)
    {
        f>>x>>y;
        G[x].push_back(y);
    }
    q.push(s);
    while (!q.empty())
        Bfs(q.front(), cc);
    for (int i=1; i<=n; ++i) if (!viz[i]) cost[i]=-1;
    for (int i=1; i<=n; ++i) g<<cost[i]<<' ';
    g<<'\n';
    f.close();
    g.close();
    return 0;
}