Trie Node Design and Initialization in DSA Go - Execution Trace

Concept Flow - Trie Node Design and Initialization

Start: Create Trie Node

↓

Initialize children array/map

↓

Set isEndOfWord to false

↓

Node ready for insertion/search

This flow shows how a trie node is created by initializing its children and setting the end-of-word flag to false.

Execution Sample

DSA Go

type TrieNode struct {
    children [26]*TrieNode
    isEndOfWord bool
}

func NewTrieNode() *TrieNode {
    return &TrieNode{}
}

This code defines a trie node with 26 children pointers and a boolean flag, then creates a new node with default values.

Execution Table

Step	Operation	Children Array	isEndOfWord	Visual State
1	Create new TrieNode struct	Empty array of 26 nil pointers	false (default)	Node with 26 nil children, isEndOfWord=false
2	Return pointer to new node	Same as above	false	Node ready for use in trie operations
Exit	Initialization complete	No changes	No changes	Node initialized with empty children and isEndOfWord=false

💡 Node is fully initialized with empty children and isEndOfWord set to false

Variable Tracker

Variable	Start	After Step 1	After Step 2	Final
children	nil	Array of 26 nil pointers	Array of 26 nil pointers	Array of 26 nil pointers
isEndOfWord	false (zero value)	false	false	false
node pointer	nil	Points to new TrieNode struct	Same	Same

Key Moments - 3 Insights

Why are all children pointers nil initially?

Because no words are inserted yet, so no child nodes exist. See execution_table step 1 where children array is empty (nil pointers).

Why is isEndOfWord set to false at initialization?

Because the node does not represent the end of any word yet. This is shown in execution_table step 1 and remains false until a word ends here.

What does the children array represent?

It represents possible next letters (a-z). Each index corresponds to a letter. Initially all nil means no next nodes. See variable_tracker children row.

Visual Quiz - 3 Questions

Look at the execution_table at step 1, what is the state of the children array?

A Array of 26 booleans set to false

B Array of 26 pointers all pointing to new nodes

C Array of 26 pointers all set to nil

D Array of 26 integers set to zero

💡 Hint

Check the 'Children Array' column in execution_table step 1

At which step is the node pointer created and returned?

A Step 2

B Step 1

C Exit step

D Before step 1

💡 Hint

Look at the 'Operation' column in execution_table for pointer creation

If isEndOfWord was set to true at initialization, what would change in the variable_tracker?

A children array would be initialized differently

B isEndOfWord would be true from start and remain true

C node pointer would be nil

D No change at all

💡 Hint

Check the 'isEndOfWord' row in variable_tracker for its values

Concept Snapshot

Trie Node Design:
- children: array of 26 pointers (for a-z)
- isEndOfWord: bool flag
Initialization:
- children all nil
- isEndOfWord false
Use NewTrieNode() to create nodes ready for trie operations

Full Transcript

A trie node is a structure with an array of 26 pointers representing letters a to z and a boolean flag isEndOfWord. When a node is created, its children pointers are all nil, meaning no child nodes exist yet. The isEndOfWord flag is set to false because the node does not mark the end of a word initially. The NewTrieNode function returns a pointer to this newly created node. This setup prepares the node for insertion and search operations in the trie.