CODE EXAMPLE FOR PYTHON

Breath First Search

// Java Breath First Search
// ------------------------

import java.util.*;                

public class BreathFirstSearch {

    int V;
    ArrayList<Integer> adj[];

    BreathFirstSearch(int noofvertex) {
        V = noofvertex;
        adj = new ArrayList[noofvertex];
        for (int i = 0; i < noofvertex; i++) {
            adj[i] = new ArrayList<>();
        }
    }

    void edge(int x, int y) {
        adj[x].add(y);
    }

    void bfs(int sourcevertex) {
        boolean[] visited = new boolean[V];
        ArrayList<Integer> a1 = new ArrayList<Integer>();
        visited[sourcevertex] = true;
        a1.add(sourcevertex);
        while (!a1.isEmpty()) {
            sourcevertex = a1.remove(0);
            System.out.print(sourcevertex + "");
            Iterator i = adj[sourcevertex].iterator();
            while (i.hasNext()) {
                int n = (int)  i.next();
                if (!visited[n]) {
                    visited[n] = true;
                    a1.add(n);
                }
            }
        }

    }

    public static void main(String[] args) {
        BreathFirstSearch g1 = new BreathFirstSearch(6);
        g1.edge(0, 1);
        g1.edge(0, 2);
        g1.edge(0, 5);
        g1.edge(1, 0);
        g1.edge(1, 2);
        g1.edge(2, 0);
        g1.edge(2, 1);
        g1.edge(2, 3);
        g1.edge(2, 4);
        g1.edge(3, 2);
        g1.edge(4, 2);
        g1.edge(4, 5);
        g1.edge(5, 0);

        g1.bfs(0);
    }
}