Cod sursa(job #2174764)

Utilizator nexiunAlin Ivan nexiun Data 16 martie 2018 13:21:30
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.12 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");

int n,m,s;
vector <int> muchii[100002];
vector <int> distanta;
queue <int> coada;

void citire()
{
    int x,y;
    fin>>n>>m>>s;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        muchii[x].push_back(y);
    }
    distanta.push_back(-1);
    for(int i=1;i<=n;i++)
    {
        if(s==i)
            distanta.push_back(0);
        else
            distanta.push_back(-1);
    }

}

void BFS()
{
    int nod, vecin;
    while(!coada.empty())
    {
        nod=coada.front();
        coada.pop();
        for(unsigned int i=0;i<muchii[nod].size();i++)
        {
            vecin=muchii[nod][i];
            if(distanta[vecin]==-1)
            {
                coada.push(vecin);
                distanta[vecin]=distanta[nod]+1;
            }
        }
    }
}

void rezolvare()
{
    coada.push(s);
    BFS();
    for(int i=1;i<=n;i++)
        fout<<distanta[i]<<' ';
}

int main()
{
    citire();
    rezolvare();
    return 0;
}