Cod sursa(job #885277)

Utilizator DarianDarian Sastre Darian Data 21 februarie 2013 19:43:17
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.9 kb
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

ifstream in("bfs.in");
ofstream out("bfs.out");

const int N = 100001;

vector <int> a[N];

int n,s,d[N];
queue<int> q;

void citire()
{
    int x,y,m,i;
    in>>n>>m>>s;
    for (i=1; i<=m; i++)
    {
        in>>x>>y;
        a[x].push_back(y);
    }
}

void init()
{
    for (int i=1; i<=N; i++)
        d[i]=-1;
}

void bfs(int nod)
{
    int x, y;
    init();
    q.push(nod);
    d[nod] = 0;
    while(!q.empty())
    {
        x = q.front();
        q.pop();
        for(int i=0; i<=a[x].size(); i++)
        {
            y = a[x][i];
            if(d[y]==-1)
            {
                q.push(y);
                d[y] = 1 + d[x];
            }
        }
    }
}


int main()
{
    citire();
    bfs(s);
    for (int i=1; i<=n; i++)
        out<<d[i]<<" ";
    return 0;
}