Trie Node Design and Initialization in DSA Typescript - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a TrieNode class with a children map.

DSA Typescript

class TrieNode {
  children: Map<string, TrieNode> = new Map();
  isEndOfWord: boolean = false;

  constructor() {
    this.children = new [1]();
  }
}

Drag options to blanks, or click blank then click option'

ASet

BMap

CArray

DObject

Attempts:

3 left

💡 Hint

Common Mistakes

Using Array instead of Map for children.

Using Set which does not store key-value pairs.

A TrieNode uses a Map to store children nodes keyed by characters for efficient lookup.

2fill in blank

medium

Complete the code to add a child node for a given character in the TrieNode.

DSA Typescript

addChild(char: string) {
  if (!this.children.has(char)) {
    this.children.set(char, new [1]());
  }
}

Drag options to blanks, or click blank then click option'

AMap

BNode

CTrieNode

DSet

Attempts:

3 left

💡 Hint

Common Mistakes

Using Map or Set instead of TrieNode for child nodes.

Using an undefined class name like Node.

Each child is a new TrieNode instance representing the next character.

3fill in blank

hard

Fix the error in the constructor to initialize isEndOfWord correctly.

DSA Typescript

constructor() {
  this.children = new Map();
  this.isEndOfWord = [1];
}

Drag options to blanks, or click blank then click option'

Afalse

Btrue

Cnull

Dundefined

Attempts:

3 left

💡 Hint

Common Mistakes

Setting isEndOfWord to true by default.

Using null or undefined which are not booleans.

isEndOfWord should start as false because the node initially does not mark the end of a word.

4fill in blank

hard

Fill both blanks to check if a character exists and retrieve its child node.

DSA Typescript

getChild(char: string): TrieNode | undefined {
  if (this.children.[1](char)) {
    return this.children.[2](char);
  }
  return undefined;
}

Drag options to blanks, or click blank then click option'

Ahas

Bget

Cset

Ddelete

Attempts:

3 left

💡 Hint

Common Mistakes

Using set() instead of get() to retrieve a value.

Using delete() which removes a key.

Use has() to check existence and get() to retrieve the child node from the Map.

5fill in blank

hard

Fill all three blanks to implement a method that marks the node as end of a word and adds a child if missing.

DSA Typescript

markEndAndAddChild(char: string) {
  this.isEndOfWord = [1];
  if (!this.children.[2](char)) {
    this.children.[3](char, new TrieNode());
  }
}

Drag options to blanks, or click blank then click option'

Atrue

Bhas

Cset

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Setting isEndOfWord to false instead of true.

Using get() instead of has() to check existence.

Using delete() instead of set() to add child.

Set isEndOfWord to true, check existence with has(), and add child with set().