Cod sursa(job #2681451)

Utilizator toma_ariciuAriciu Toma toma_ariciu Data 5 decembrie 2020 15:12:13
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.22 kb
#include <fstream>
#include <iostream>
#include <vector>
#include <queue>
#include <cstring>

using namespace std;

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

vector <int> G[100005];
queue <int> q;
int dist[100005];
const int maxdist=0x3f3f3f3f;

bool IsWorth(int vecin, int pozitie)
{
    return dist[pozitie]+1 < dist[vecin];
}
int bfs(int origine)
{
    memset(dist, maxdist, sizeof dist);
    q.push(origine);
    dist[origine]=0;
    while(!q.empty())
    {
        int pozitie=q.front();
        q.pop();
        for(int i=0; i<G[pozitie].size(); i++)
        {
            int vecin=G[pozitie][i];
            if(IsWorth(vecin, pozitie))
            {
                dist[vecin]=dist[pozitie]+1;
                q.push(vecin);
            }
        }
    }
}
int main()
{
    int nr_noduri, nr_muchii, sursa;
    fin>>nr_noduri>>nr_muchii>>sursa;
    sursa--;
    for(int i=0; i<nr_muchii; i++)
    {
        int nod1, nod2;
        fin>>nod1>>nod2;
        G[nod1-1].push_back(nod2-1);
    }
    bfs(sursa);
    for(int i=0; i<nr_noduri; i++)
    {
        if(dist[i]==maxdist)
            fout<<-1<<' ';
        else
            fout<<dist[i]<<' ';
    }
    return 0;
}