Cod sursa(job #1995457)

Utilizator FredyLup Lucia Fredy Data 28 iunie 2017 00:21:31
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.84 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

#define lim 100010
int n,m,s,path[lim];
vector <int> G[lim];


void bfs()
{
    queue <int> q;
    int act;
    path[s]=0;
    q.push(s);

    while(!q.empty())
    {
        act=q.front();
        q.pop();
        for(auto it:G[act])
            if(path[it]==-1)
            {
                path[it]=path[act]+1;
                q.push(it);
            }
    }
}


int main()
{
    int x,y;
    fin>>n>>m>>s;
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        G[x].push_back(y);
    }

    for(int i=1; i<=n; i++) path[i]=-1;

    bfs();

    for(int i=1; i<=n; i++)
        fout<<path[i]<<' ';

    fin.close();
    fout.close();
    return 0;
}