Cod sursa(job #1177416)

Utilizator andi23roscaRosca Andrei andi23rosca Data 26 aprilie 2014 12:29:09
Problema BFS - Parcurgere in latime Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.06 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

#define maxn 100010

using namespace std;

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

vector<long> muchii[maxn];

queue<long> coada;

long vizitati[maxn], cost[maxn], ok=0;

int main()
{
    long n,m,s,i,distanta=0,nod,x,y;

    vector<long>::iterator it;

    f>>n>>m>>s;

    for(i=1;i<=m;i++)
    {
        f>>x>>y;

        muchii[x].push_back(y);

        if(x==s && y==s)
                ok=1;
    }

    coada.push(s);

    while(!coada.empty())
    {
        nod = coada.front();
        vizitati[nod] = 1;
        distanta = cost[nod] + 1;
        coada.pop();

        for(it = muchii[nod].begin(); it != muchii[nod].end(); it++)
        {
            if(vizitati[*it] != 1)
            {
                coada.push(*it);
                cost[*it] = distanta;
            }
        }

    }

    for(i=1;i<=n;i++)
    {
        if(cost[i]==0 && i!=s)
            g<<"-1 ";
        else g<<cost[i]<<" ";
    }


    return 0;
}