Cod sursa(job #2924361)

Utilizator AndreiJJIordan Andrei AndreiJJ Data 30 septembrie 2022 15:16:11
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.12 kb
#include <iostream>
#include <algorithm>
#include <fstream>
#include <queue>
#include <vector>
#include <cmath>
using namespace std;

const int oo = 2e9;

vector <int> L[100001], dist(100001, oo);
int n, m, start;
queue <int> q;

void BFS(int node)
{
    dist[node] = 0;
    q.push(node);
    while (!q.empty())
    {
        int curr = q.front();
        q.pop();
        /*for (int i = 0; i < L[curr].size(); i++)
            if (dist[L[curr][i]] > 1 + dist[curr])
            {
                dist[L[curr][i]] = 1 + dist[curr];
                q.push(L[curr][i]);
            }*/
        for (auto& next : L[curr])
            if (dist[next] > 1 + dist[curr])
            {
                dist[next] = 1 + dist[curr];
                q.push(next);
            }
    }
}

int main()
{
    ifstream fin ("bfs.in");
    ofstream fout ("bfs.out");
    fin >> n >> m >> start;
    while (m--)
    {
        int x, y;
        fin >> x >> y;
        L[x].push_back(y);
        //L[y].push_back(x);
    }
    BFS(start);
    for (int i = 1; i <= n; i++)
        if (dist[i] == oo) fout << "-1 ";
        else fout << dist[i] << " ";
    return 0;
}