Cod sursa(job #2870770)

Utilizator andreimocianAndrei Mocian andreimocian Data 12 martie 2022 15:51:27
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.11 kb
#include <iostream> 
#include <fstream> 
#include <vector>
#include <queue>

using namespace std; 

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

const int NMAX = 100005;
int n, m, s;
vector < int > L[NMAX];
queue < int > Q;
int dist[NMAX];

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

void BFS()
{
    int nod;
    for(int i = 1; i <= n; i++)
    {
        dist[i] = 1e9;
    }
    Q.push(s);
    dist[s] = 0;
    while(!Q.empty())
    {
        nod = Q.front();
        Q.pop();
        for(auto it : L[nod])
        {
            if(dist[it] == 1e9)
            {
                dist[it] = 1 + dist[nod];
                Q.push(it);
            }
        }
    }
}

void afisare()
{
    for(int i = 1; i <= n; i++)
    {
        if(dist[i] == 1e9)
        {
            fout << -1 << " ";
        }
        else
        {
            fout << dist[i] << " ";
        }
    }
}

int main()
{ 
    citire();
    BFS();
    afisare();
    return 0;
}