Cod sursa(job #3128736)

Utilizator PetraPetra Hedesiu Petra Data 10 mai 2023 18:06:33
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.92 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <string.h>

using namespace std;

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

vector<int> G[100005];
queue<pair<int, int>> q;

int n, m, s, viz[100005], dist[100005];

void bfs (int s)
{
    memset(dist, 0x3f, sizeof(dist));
    q.push(make_pair(s, 0));
    while (!q.empty())
    {
        int c = q.front().first, d = q.front().second;
        q.pop();

        if (viz[c]) continue;
        viz[c] = 1;
        dist[c] = d;

        for (int i = 0; i < G[c].size(); i++)
            q.push(make_pair(G[c][i], d + 1));
    }
}

int main()
{
    fin >> n >> m >> s;
    for (int i = 1; i <= m; i++)
    {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
    }
    bfs(s);
    for (int i = 1; i <= n; i++)
        fout << (dist[i]==0x3f3f3f3f ? -1 : dist[i]) << " ";
    return 0;
}