Autocomplete System with Trie in DSA Go - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new Trie node.

DSA Go

func NewTrieNode() *TrieNode {
    return &TrieNode{
        children: make(map[rune]*TrieNode),
        isEnd:    [1],
    }
}

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

A0

Btrue

Cnil

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Setting isEnd to true for new nodes

Using nil instead of a boolean value

The new Trie node should start with isEnd set to false because it does not represent the end of a word yet.

2fill in blank

medium

Complete the code to insert a word into the Trie.

DSA Go

func (t *Trie) Insert(word string) {
    node := t.root
    for _, ch := range word {
        if node.children[ch] == nil {
            node.children[ch] = NewTrieNode()
        }
        node = node.children[[1]]
    }
    node.isEnd = true
}

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Ach

Bword

Cnode

Dt

Attempts:

3 left

💡 Hint

Common Mistakes

Using the whole word instead of the character

Using the node variable instead of the character

We move to the child node corresponding to the current character ch in the word.

3fill in blank

hard

Fix the error in the search function to check if a word exists in the Trie.

DSA Go

func (t *Trie) Search(word string) bool {
    node := t.root
    for _, ch := range word {
        if node.children[ch] == nil {
            return false
        }
        node = node.children[ch]
    }
    return node.[1]
}

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

Achildren

Broot

CisEnd

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Returning children instead of isEnd

Returning root or word which are not boolean flags

After traversing all characters, we return isEnd to confirm the word ends here.

4fill in blank

hard

Fill both blanks to collect all words starting with a prefix using DFS.

DSA Go

func (t *Trie) collectWords(node *TrieNode, prefix string, results *[]string) {
    if node.[1] {
        *results = append(*results, prefix)
    }
    for ch, child := range node.[2] {
        t.collectWords(child, prefix+string(ch), results)
    }
}

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

AisEnd

Broot

Cchildren

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Using root instead of children for traversal

Checking children instead of isEnd for word completion

Check isEnd to add words, and loop over children to explore next nodes.

5fill in blank

hard

Fill all three blanks to implement the Autocomplete function returning all words with a prefix.

DSA Go

func (t *Trie) Autocomplete(prefix string) []string {
    node := t.root
    for _, ch := range prefix {
        if node.children[[1]] == nil {
            return []string{}
        }
        node = node.children[ch]
    }
    results := []string{}
    t.collectWords(node, [2], &results)
    return [3]
}

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

Ach

Bprefix

Cresults

Dnode

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable to check children

Passing wrong string to collectWords

Returning node instead of results

Use ch to check children, pass prefix to collectWords, and return results array.