Cod sursa(job #2487760)

Utilizator EduardTudosaEduard Bogdan EduardTudosa Data 5 noiembrie 2019 18:28:21
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.06 kb
#include <fstream>
#include <vector>
#include <bits/stdc++.h>
#include <queue>

using namespace std;

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

int n , m , x , y , s;

queue <int> Q;
vector <int> G[100001];
bool viz[100001];
int lg[100001];

void bfs(int nod)
{
    Q.push(nod);
    while(!Q.empty())
    {
        int curent = Q.front();
        Q.pop();
        for(vector <int> :: iterator it = G[curent].begin() ; it != G[curent].end() ; it ++)
            if(!viz[*it])
            {
                lg[*it] = lg[curent] + 1;
                viz[*it] = 1;
                Q.push(*it);
            }
    }
}

int main()
{
    fin >> n >> m >> s;
    for(int i = 1 ; i <= m ; i ++)
    {
        fin >> x >> y;
        G[x].push_back(y);
    }
    viz[s] = 1;
    bfs(s);
    for(int i = 1 ; i <= n ; i ++)
        if(i != s && lg[i] == 0)
            fout << -1 << ' ';
        else if(i == s)
            fout << 0 << ' ';
        else
            fout << lg[i] << ' ';
    fin.close();
    fout.close();
    return 0;
}