Cod sursa(job #2502444)

Utilizator NicuCNicu Capatina NicuC Data 30 noiembrie 2019 20:52:55
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.91 kb
#include <bits/stdc++.h>

#define NMAX 100001

using namespace std;

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

int n, m, s, i, x, y, viz[NMAX];

vector<int> L[NMAX];
queue<int> c;

void BFS(int nod) {
    int k;
    c.push(nod);
    viz[nod] = 0;
    while (!c.empty()) {
        k = c.front();
        c.pop();
        for (int &cnt : L[k]) {
            if (!viz[cnt]) {
                c.push(cnt);
                viz[cnt] = viz[k] + 1;
            }
        }
    }
}

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

    BFS(s);

    for (i = 1; i <= n; i++)
        if (i == s)
            fout << 0 << ' ';
        else {
            if (viz[i] == 0)
                fout << -1 << ' ';
            else
                fout << viz[i] << ' ';
        }
    return 0;
}