Cod sursa(job #2974302)

Utilizator IanisBelu Ianis Ianis Data 3 februarie 2023 20:22:57
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.9 kb
#include <fstream>
#include <iostream>
#include <vector>
#include <queue>

using namespace std;

#ifdef LOCAL
ifstream fin("input.txt");
#define fout cout
#else
#include <bits/stdc++.h>
ifstream fin("bfs.in");
ofstream fout("bfs.out");
#endif

const int NMAX = 1e5+5;

int n, m, s;
int ans[NMAX];
vector<int> g[NMAX];
queue<int> qe;

void read() {
    fin >> n >> m >> s;
    for (int i = 1; i <= m; i++) {
        int x, y;
        fin >> x >> y;
        g[x].push_back(y);
    }
}

void bfs() {
    for (int i = 1; i <= n; i++)
        ans[i] = -1;

    qe.push(s);
    ans[s] = 0;
    while (!qe.empty()) {
        int x = qe.front();
        qe.pop();
        for (auto &it : g[x])
            if (ans[it] == -1) {
                qe.push(it);
                ans[it] = ans[x] + 1;
            }
    }
}
int main() {
    read();
    bfs();
    for (int i = 1; i <= n; i++)
        fout << ans[i] << ' ';
    return 0;
}