Cod sursa(job #2446037)

Utilizator StanCatalinStanCatalin StanCatalin Data 6 august 2019 20:20:54
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.03 kb
#include <iostream>
#include <vector>
#include <fstream>
#include <queue>

using namespace std;

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

const int dim = 100005;

int n,m,s;
int dist[dim];

vector <int> v[dim];
queue <int> pq;

void BFS(int s)
{
    int nod;
    pq.push(s);
    dist[s] = 1;
    while (!pq.empty())
    {
        nod = pq.front();
        pq.pop();
        for (int i=0; i<v[nod].size(); i++)
        {
            if (dist[v[nod][i]] >= dist[nod] + 1)
            {
                dist[v[nod][i]] = dist[nod] + 1;
                pq.push(v[nod][i]);
            }
        }
    }
}

int main()
{
    int x,y;
    in >> n >> m >> s;
    for (int i=1; i<=m; i++)
    {
        in >> x >> y;
        v[x].push_back(y);
    }
    for (int i=1; i<=n; i++)
    {
        dist[i] = dim;
    }
    BFS(s);
    for (int i=1; i<=n; i++)
    {
        if (dist[i] == dim)
        {
            out << "-1 ";
        }
        else out << dist[i] - 1 << " ";
    }
    return 0;
}