Apple Interview Question for Software Engineers


Country: United States




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1
of 1 vote

public String bstSearch(TreeNode<Integer> node , int num){
		if (node == null){
			return "NotFound";
		}
		if (node.val == num){
			return "Undefined";
		}
		String str = bst(node, num);
		return str;
	}
	
	public String bst(TreeNode<Integer> node, int num){
		if (node == null){
			return "NotFound";
		}
		if (node.val == num){
			return "found";
		}
		if (num < node.val){
			String str1 = bst(node.left, num);
			if (str1.equals("NotFound")){
				return str1;
			}
			else if (str1.equals("found")){
				return "0";
			}
			else {
				return "0"+str1;
			}
		}
		if (num > node.val){
			String str1 = bst(node.right, num);
			if (str1.equals("NotFound")){
				return str1;
			}
			else if (str1.equals("found")){
				return "1";
			}
			else {
				return "1"+str1;
			}
		}
		return null;
	}


class TreeNode<T> {
	      T val;
	      TreeNode left;
	      TreeNode right;
	      TreeNode(T x) { val = x; }
 }

- Kush June 18, 2017 | Flag Reply
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1
of 1 vote

Solution in python

class node(object):
    def __init__(self, value):
        self.value = value
        self.left = None
        self.right = None
    
    
def buildABCString(root, value):
    res  = ""
    if root.value == value: return "Undefined"
    node = root
    while node != None:
        if node.value == value: return res
        elif value > node.value:
            res += "1"
            node = node.right
        else:
            res += "0"
            node = node.left
    return "Not Found"

- Fernando June 19, 2017 | Flag Reply
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0
of 0 vote

Not exactly proud of it, but:

def BST : {
    $$ : def(){
        $.root = null
    },
    add_node : def(v){
      new_node = {'v' : v , 'l' : null , 'r' : null }  
      if ( empty($.root) ){
          $.root = new_node
          return $.root 
      } 
      parent = $.root
      current = v < parent.v  ? parent.l : parent.r 
      while ( current != null ){
         parent = current
         current = v < parent.v  ? parent.l : parent.r   
      } 
      if ( v < parent.v ){
          parent.l = new_node
      } else if ( parent.v < v ){
          parent.r = new_node
      }    
    },
    find_abc : def(key){
      current = $.root 
      path = ''
      while ( current != null && current.v != key ){
         if (  key < current.v ){
            path += '0'  
            current = current.l 
         } else if ( current.v < key ){
            path += '1'
            current = current.r 
         }
      }
      (!empty(current) && current.v == key)? path : 'Not Found'
    }
}
//now play 
bst = new ( BST )
values = [5,2,8,3,6,9,1]
// add nodes 
for ( v : values ){ bst.add_node(v) }
keys =  [6, 1, 10, 2]
// print ABC ... 
for ( v : keys ){ printf( '%s -> %s%n', v, bst.find_abc(v) ) }

- NoOne June 17, 2017 | Flag Reply
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0
of 0 vote

public String bstNotation(int num) {
		if (root == null) return "Not Found";
		Node curr = root;
		StringBuilder notation = new StringBuilder();
		if(root.data==num)
			return "Undefined";
		
		while (curr != null) {
			if (num<curr.data) {
				curr = curr.left;
				notation.append("0");
			} else if (num>curr.data) {
				curr = curr.right;
				notation.append("1");
			} else if (num==curr.data) {
				return notation.toString();
			} 
		}
		return "Not Found";
	}

- MS June 24, 2017 | Flag Reply
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0
of 0 vote

public class ABCNotation
{
	class Node<T extends Comparable<T>>
	{
		T data;
		Node<T> lchild = null, rchild = null;
		Node(T data)
		{
			this.data = data;
		}
	}
	
	class Tree<T extends Comparable<T>>
	{
		Node<T> root = null;
		
		public Node<T> insert(T data)
		{
			Node<T> newNode = new Node<T>(data);
			if(root == null)
				root = newNode;
			else
				insertAtNode(newNode, root);
			return newNode;
		}
		
		private void insertAtNode(Node<T> node, Node<T> root)
		{
			switch (node.data.compareTo(root.data))
			{
			case 0:
			case -1: if(root.lchild != null) insertAtNode(node, root.lchild); else root.lchild = node; break;
			case 1: if(root.rchild != null) insertAtNode(node, root.rchild); else root.rchild = node; break;
			}
		}
	}
	
	class BoolRef
	{
		boolean value = false;
	}
	
	private String findABCNotation(Tree<Integer> tree, Integer num)
	{
		Node<Integer> root = tree.root;
		if(root.data == num)
		{
			return("Undefined");
		}
		else
		{
			StringBuilder sb = new StringBuilder();
			BoolRef isFound = new BoolRef();
			findABCNotation(root, num, sb, isFound);
			if(isFound.value)
				return sb.toString();
			else
				return "NotFound";
		}
	}
	
	private void findABCNotation(Node<Integer> node, Integer num, StringBuilder sb, BoolRef isFound)
	{
		switch (node.data.compareTo(num))
		{
		case 0: isFound.value = true; break;
		case 1: if(node.lchild != null) {sb.append("0"); findABCNotation(node.lchild, num, sb, isFound);} else isFound.value =false; break;
		case -1: if(node.rchild != null) {sb.append("1");findABCNotation(node.rchild, num, sb, isFound);} else isFound.value =false; break;
		}
	}
	
	public static void main(String[] args)
	{
		ABCNotation abc = new ABCNotation();
		ABCNotation.Tree<Integer> tree = abc.new Tree<>();
		tree.insert(5);
		tree.insert(2);
		tree.insert(8);
		tree.insert(3);
		tree.insert(6);
		tree.insert(9);
		tree.insert(1);
		System.out.println(abc.findABCNotation(tree, 6));
		System.out.println(abc.findABCNotation(tree, 1));
		System.out.println(abc.findABCNotation(tree, 10));
		System.out.println(abc.findABCNotation(tree, 2));
		
	}

}

- manchinagarjuna July 20, 2017 | Flag Reply
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0
of 0 vote

package com.prep.tree;

public class BinaryTreeNotationABCQuestion {

	Node root;
	
	BinaryTreeNotationABCQuestion()
	{
		root = null;
	}
	
	public void insertRec(int data){
		root = insertInTree(root,data);
	}
	public Node insertInTree(Node root,int data){
		
		if (root == null){
			root = new Node(data);
			return root;
		}
		if(data<root.key){
			root.left = insertInTree(root.left,data);
		}
		else if(data>root.key){
			root.right = insertInTree(root.right,data);
		}
		return root;
	}
	
	public String findRec(int data){
		String a = findAnotations(root,data);
		return a;
	}
	public String findAnotations(Node root,int value){
		//return 0 for left
		// return 1 for right
		//retrun Not Found for item not Found
		// return Undefined is root is null
		
		String annotation = "";
		if(root==null){
			//System.out.println("NotFound");
			annotation = "NotFound";
			return annotation;
		}
		if(root.key==value){
			return annotation;
		}
		if(value<root.key){
			annotation = annotation+"0";
			String a = findAnotations(root.left,value);
			if(a!="NotFound"){
			annotation = annotation + a;
			}
			else {
				annotation = a;
			}
		}
		
		if(value>root.key){
			annotation = annotation+"1";
			String a = findAnotations(root.right,value);
			if(a!="NotFound"){
				annotation = annotation + a;
				}
				else {
					annotation = a;
				}
		}
		return annotation;
	}
	
	public static void main(String[] args)
	{
		BinaryTreeNotationABCQuestion tree = new BinaryTreeNotationABCQuestion();
	//				tree.root = new Node(100);
	//				tree.root.left = new Node(60);
	//				tree.root.right = new Node(150);
	//				tree.root.left.left = new Node(45);
	//				tree.root.left.right = new Node(75);

	tree.insertRec(5);
	tree.insertRec(2);
	tree.insertRec(8);
	tree.insertRec(3);
	tree.insertRec(6);
	tree.insertRec(9);
	tree.insertRec(1);
	
	String c = tree.findRec(1);
	String d = tree.findRec(6);
	String e = tree.findRec(10);
	String f = tree.findRec(2);
	System.out.println(c);
	System.out.println(d);
	System.out.println(e);
	System.out.println(f);
	}
}

- anonymousNg August 28, 2017 | Flag Reply
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0
of 0 vote

public void getABCNotation(Node n,int no,StringBuilder stb){
if(n == null){
stb.delete(0,stb.length());
stb.append("Not Found");
return;
}
if(n.value == no ){
return ;
}else{
if(n.value > no){
stb.append("0");
getABCNotation(n.left,no,stb);
}else {
stb.append("1");
getABCNotation(n.right,no,stb);
}
}
}

- Anonymous September 12, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

{{ public void getABCNotation(Node n,int no,StringBuilder stb){
if(n == null){
stb.delete(0,stb.length());
stb.append("Not Found");
return;
}
if(n.value == no ){
return ;
}else{
if(n.value > no){
stb.append("0");
getABCNotation(n.left,no,stb);
}else {
stb.append("1");
getABCNotation(n.right,no,stb);
}
}
}
}}

- Anonymous September 12, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

public void getABCNotation(Node n,int no,StringBuilder stb){
        if(n == null){
            stb.delete(0,stb.length());
            stb.append("Not Found");
            return;
        }
        if(n.value == no ){
            return ;
        }else{
            if(n.value > no){
                stb.append("0");
                getABCNotation(n.left,no,stb);
            }else   {
                stb.append("1");
                getABCNotation(n.right,no,stb);
            }
        }

}

- trooper September 12, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

public void getABCNotation(Node n,int no,StringBuilder stb){
        if(n == null){
            stb.delete(0,stb.length());
            stb.append("Not Found");
            return;
        }
        if(n.value == no ){
            return ;
        }else{
            if(n.value > no){
                stb.append("0");
                getABCNotation(n.left,no,stb);
            }else   {
                stb.append("1");
                getABCNotation(n.right,no,stb);
            }
        }
    }

- trooper September 12, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

public void getABCNotation(Node n,int no,StringBuilder stb){
        if(n == null){
            stb.delete(0,stb.length());
            stb.append("Not Found");
            return;
        }
        if(n.value == no ){
            return ;
        }else{
            if(n.value > no){
                stb.append("0");
                getABCNotation(n.left,no,stb);
            }else   {
                stb.append("1");
                getABCNotation(n.right,no,stb);
            }
        }

}

- Trooper September 12, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

public void getABCNotation(Node n,int no,StringBuilder stb){
        if(n == null){
            stb.delete(0,stb.length());
            stb.append("Not Found");
            return;
        }
        if(n.value == no ){
            return ;
        }else{
            if(n.value > no){
                stb.append("0");
                getABCNotation(n.left,no,stb);
            }else   {
                stb.append("1");
                getABCNotation(n.right,no,stb);
            }
        }
    }

- Trooper September 12, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

solution

- trooper September 12, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

public void getABCNotation(Node n,int no,StringBuilder stb){
        if(n == null){
            stb.delete(0,stb.length());
            stb.append("Not Found");
            return;
        }
        if(n.value == no ){
            return ;
        }else{
            if(n.value > no){
                stb.append("0");
                getABCNotation(n.left,no,stb);
            }else   {
                stb.append("1");
                getABCNotation(n.right,no,stb);
            }
        }
    }

- trooper September 12, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

public void getABCNotation(Node n,int no,StringBuilder stb){
        if(n == null){
            stb.delete(0,stb.length());
            stb.append("Not Found");
            return;
        }
        if(n.value == no ){
            return ;
        }else{
            if(n.value > no){
                stb.append("0");
                getABCNotation(n.left,no,stb);
            }else   {
                stb.append("1");
                getABCNotation(n.right,no,stb);
            }

}

- trooper September 12, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

public void getABCNotation(Node n,int no,StringBuilder stb){
        if(n == null){
            stb.delete(0,stb.length());
            stb.append("Not Found");
            return;
        }
        if(n.value == no ){
            return ;
        }else{
            if(n.value > no){
                stb.append("0");
                getABCNotation(n.left,no,stb);
            }else   {
                stb.append("1");
                getABCNotation(n.right,no,stb);
            }
        }
    }

- trooper September 12, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

public void getABCNotation(Node n,int no,StringBuilder stb){
        if(n == null){
            stb.delete(0,stb.length());
            stb.append("Not Found");
            return;
        }
        if(n.value == no ){
            return ;
        }else{
            if(n.value > no){
                stb.append("0");
                getABCNotation(n.left,no,stb);
            }else   {
                stb.append("1");
                getABCNotation(n.right,no,stb);
            }
        }

}

- Trooper September 12, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

public static String navigate(Node root, int data) {
    if (root == null) {
      return "NotFound";
    }
    if (root.data == data) {
      return "Undefined";
    }

    StringBuilder result = new StringBuilder();
    while (root != null) {
      if ( data < root.data) {
        result.append("0");
        root = root.left;
      } else if ( data > root.data) {
        result.append("1");
        root = root.right;
      } else {
        return result.toString();
      }
    }
    return "NotFound";
  }

- Kannan October 07, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

public static String navigate(Node root, int data) {
    if (root == null) {
      return "NotFound";
    }
    if (root.data == data) {
      return "Undefined";
    }

    StringBuilder result = new StringBuilder();
    while (root != null) {
      if ( data < root.data) {
        result.append("0");
        root = root.left;
      } else if ( data > root.data) {
        result.append("1");
        root = root.right;
      } else {
        return result.toString();
      }
    }
    return "NotFound";
  }

- Kannan October 07, 2017 | Flag Reply


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