Cod sursa(job #2279778)

Utilizator ikogamesIon Ceaun ikogames Data 9 noiembrie 2018 23:08:16
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.89 kb
#include <bits/stdc++.h>
#define N 100005
using namespace std;

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

vector <int> h[N];
int dist[N], n , m, s;
bool viz[N];
queue <int> q;

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

void BFS(int sNode)
{
    int cNode;
    viz[sNode] = 1;
    q.push(sNode);
    while (!q.empty() )
    {
        cNode = q.front();
        q.pop();
        for (auto i : h[cNode])
            if (!viz[i])
            {
                viz[i] = 1;
                dist[i] = dist[cNode] + 1;
                q.push(i);
            }
    }
}

int main()
{
    Read();
    BFS(s);
    for(int i = 1; i <= n; i++)
        if(s != i && dist[i] == 0)
            fout << "-1 ";
        else fout << dist[i] << " ";
    return 0;
}