Cod sursa(job #1442901)

Utilizator supremusChihalau Andrei supremus Data 26 mai 2015 15:44:25
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.06 kb
#include <fstream>
#include <vector>
#include <queue>
#include <iostream>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
int n,m,a,b,x,c=0,s;
vector <int> G[100001];
int viz[100001],dist[100001];


    void bfs(int nod)
    {
        queue <int>q;
        q.push(nod);
        viz[nod]=1;
        dist[nod]=0;
        while(!q.empty())
        {
            nod=q.front();q.pop();
            for(int i=0;i<G[nod].size();i++)
                if(viz[G[nod][i]]==0)
                {
                    viz[G[nod][i]]=1;
                    q.push(G[nod][i]);
                    if (dist[G[nod][i]]==0)
                        dist[G[nod][i]]=dist[nod]+1;
                }

        }

    }

int main()
{
    f>>n>>m>>s;
    for(int i=1;i<=m;i++)
    {
        f>>a>>b;
        G[a].push_back(b);
    }
    bfs(s);
    for (int i=1;i<=n;i++)
        if (i==s)
            g<<"0 ";
        else
            if (dist[i]==0)
                g<<"-1 ";
            else
                g<<dist[i]<<" ";
    return 0;
}