generic.java

package lec22;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;

public class generic {

    private Node root;

//    public class Node{
//        int value;
//        ArrayList<Node> children;
//        public Node (int value){
//            this.value = value;
//            this.children = new ArrayList<Node>();
//        }
//    }
    public void insert(Scanner s){
        System.out.println("enter root value");
        int n = s.nextInt();
        this.root = new Node(n);
        insert(root,s);
    }
    private void insert(Node node, Scanner s){
        while(true){
            System.out.println(" more node of "+ node.value);
            boolean yes = s.nextBoolean();

            if(yes){
                System.out.println("Enter the value of child");
                int value = s.nextInt();
                Node child = new Node(value);
                root.children.add(child);
                insert(child,s);
            }
            else{
                break;
            }
        }

    }

    public void display(){
        display(root," ");
    }

    private void display(Node node,String indent){
        System.out.println(indent+node.value);
        for (int i = 0; i <node.children.size() ; i++) {
            display(node.children.get(i),indent+"\t");
        }
    }

    public int count(){
        return count(root);
    }
    private int count(Node node){
        int cnt = 1;
        for (int i = 0; i <node.children.size() ; i++) {
            cnt+= count(node.children.get(i));
        }
        return cnt;
    }


    public int max(){
        int max = root.value;
        return max(root,max);
    }
    private int max(Node node, int max){
        if(max<node.value){
            max=node.value;
        }
        for (int i = 0; i <node.children.size() ; i++) {
          max = max(node.children.get(i),max);
        }
        return max;
    }
    public void levelorder(){
        Queue<Node> queue = new LinkedList<>();
        queue.add(root);
        while(!queue.isEmpty()){
            Node temp = queue.remove();
            //printing temp.value here
         //   System.out.println(temp.value);  // just for trial
            for (int i = 0; i <temp.children.size() ; i++) {
                queue.add(temp.children.get(i));
            }

        }
    }
    public void atlevel(int k){
        atlevel(root,k);
    }

    public void atlevel(Node node, int k){
    if(k==0){
        System.out.println(node.value);
    }
        for (int i = 0; i <node.children.size() ; i++) {
            atlevel(node.children.get(i),k-1);
        }
    }


    public class Node{
        int value;
        ArrayList<Node> children;
        public Node (int value){
            this.value = value;
            this.children = new ArrayList<Node>();
        }
    }

}