Cod sursa(job #2016782)

Utilizator SCatalinStanciu Catalin SCatalin Data 30 august 2017 13:41:18
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.91 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

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

const int N = 100005;
vector <int> adj[N];
bool vis[N];
int dist[N];
queue <int> Q;
void BFS(int S)
{
    dist[S] = 0;
    vis[S] = 1;
    Q.push(S);
    while (!Q.empty())
    {
        int top = Q.front();
        Q.pop();
        for (int i = 0; i<adj[top].size(); i++)
            if (!vis[adj[top][i]])
            {
                vis[adj[top][i]] = 1;
                Q.push(adj[top][i]);
                dist[adj[top][i]] = dist[top]+1;
            }
    }
}
int main()
{
    int n,m,source,x,y;
    in >> n >> m >> source;
    for (int i = 1; i<=m; i++)
    {
        in >> x >> y;
        adj[x].push_back(y);
    }
    for (int i = 1; i<=n; i++)
        dist[i] = -1;
    BFS(source);
    for (int i = 1; i<=n; i++)
        out << dist[i] << " ";
}