Cod sursa(job #2246128)

Utilizator Ioana_AndreeaCristescu Ioana Ioana_Andreea Data 26 septembrie 2018 18:26:37
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include <fstream>
#include <vector>
#include <cstring>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
const int NMax = 100000;
vector <int> G[NMax + 5];
int N,M,Start;
int Q[NMax + 5],k;
int D[NMax + 5];
void Read()
{
    fin >> N >> M >> Start;
    for(int i = 1; i <= M; ++i)
    {
        int x,y;
        fin >> x >> y;
        G[x].push_back(y);
    }
}

void BFS()
{
    memset(D,-1,sizeof(D));
    Q[++k] = Start;
    D[Start] = 0;
    for(int j = 1; j <= k; ++j)
    {
        int Current_Node = Q[j];
        for(int i = 0; i < (int)G[Current_Node].size(); ++i)
            {
                int Vecin = G[Current_Node][i];
                if(D[Vecin] == -1)
                {
                    Q[++k] = Vecin;
                    D[Vecin] = D[Current_Node] + 1;
                }
            }
    }
}

void Print()
{
    for(int i = 1; i <= N; ++i)
        fout << D[i] << " ";
    fout << "\n";
}

int main()
{
    Read();
    BFS();
    Print();
    return 0;
}