Cod sursa(job #2795635)

Utilizator andreimocianAndrei Mocian andreimocian Data 6 noiembrie 2021 18:46:36
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.96 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

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

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()
{
    for(int i = 1; i <= n; i++)
    {
        dist[i] = 1e9;
    }
    Q.push(s);
    dist[s] = 0;
    while(!Q.empty())
    {
        int 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++)
        fout << (dist[i] == 1e9? -1 : dist[i]) << " ";
}

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