Cod sursa(job #2945807)

Utilizator raresmihociMihoci Rares raresmihoci Data 24 noiembrie 2022 09:43:31
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.89 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");

vector <int> a[100001];
queue <int> Q;

int n, m, s, x, y, viz[100001], cost[100001];

void BFS(int k)
{
    viz[k] = 1;
    Q.push(k);
    cost[k] = 0;
    while(!Q.empty())
    {
        int x = Q.front();
        for(auto it: a[x])
        {
            if(!viz[it])
            {
                viz[it] = 1;
                Q.push(it);
                cost[it] = cost[x] + 1;
            }
        }
        Q.pop();
    }
}

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

    BFS(s);

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