Cod sursa(job #2455040)

Utilizator nTropicGravityesadasdwaadwqafr nTropicGravity Data 10 septembrie 2019 17:54:11
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.11 kb
#include    <fstream>
#include    <queue>
#include    <vector>

using namespace std;

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

#define ARRAY_MAX 100005

queue <int> Queue;
vector <int> Edge[ARRAY_MAX];

int M, N, X, Y, Node, startNode, Next;
int Distance[ARRAY_MAX];

void BFS() {
    while (!Queue.empty()) {
        Node = Queue.front();
        Queue.pop();

        for (unsigned i = 0; i < Edge[Node].size(); i++) {
            Next = Edge[Node][i];

            if (Distance[Next] == -1) {
                Distance[Next] = Distance[Node] + 1;

                Queue.push(Next);
            }
        }
    }
}

void Read() {
    fin >> N >> M >> startNode;

    for (int i = 1; i <= M; i++) {
        fin >> X >> Y;

        Edge[X].push_back(Y);
    }
}

void Write() {
    for (int i = 1; i <= N; i++)
        Distance[i] = -1;

    Distance[startNode] = 0;

    Queue.push(startNode);

    BFS();

    for (int i = 1; i <= N; i++)
        fout << Distance[i] << " ";
}

int main() {
    ios_base::sync_with_stdio(false);

    Read();
    Write();
}