Trie Insert Operation in DSA C++ - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to insert a character into the children map of the current Trie node.

DSA C++

current->children['a'] = new TrieNode();
current = current->children[[1]];

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

A'a'

B'b'

C'c'

D'd'

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different character than the one inserted.

Forgetting to move current to the new node.

We insert the character 'a' into the children map and then move current to that child node.

2fill in blank

medium

Complete the code to check if the current character exists in the children map.

DSA C++

if (current->children.find(word[[1]]) == current->children.end()) {
    current->children[word[i]] = new TrieNode();
}

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

Aword

B0

Ci

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using a fixed index like 0 or 1 instead of the loop variable.

Using the whole word instead of a single character.

We check if the character at index i in the word exists in the children map.

3fill in blank

hard

Fix the error in marking the end of a word in the Trie node.

DSA C++

current->[1] = true;

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

AisEnd

BendOfWord

CisWord

DwordEnd

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name that does not exist in the TrieNode class.

Forgetting to mark the end of the word.

The correct member variable to mark the end of a word is 'isEnd'.

4fill in blank

hard

Fill both blanks to complete the loop that inserts each character of the word into the Trie.

DSA C++

for (int [1] = 0; [2] < word.size(); [2]++) {
    if (current->children.find(word[i]) == current->children.end()) {
        current->children[word[i]] = new TrieNode();
    }
    current = current->children[word[i]];
}

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

Ai

Bj

Ck

Dindex

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names in the loop declaration and condition.

Using a variable name not used inside the loop body.

The loop variable should be 'i' consistently for initialization, condition, and increment.

5fill in blank

hard

Fill all three blanks to complete the insert function for the Trie.

DSA C++

void insert(string [1]) {
    TrieNode* current = root;
    for (int i = 0; i < [2].size(); i++) {
        if (current->children.find([3][i]) == current->children.end()) {
            current->children[[3][i]] = new TrieNode();
        }
        current = current->children[[3][i]];
    }
    current->isEnd = true;
}

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

Aword

Bstr

Dtext

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inside the function than the parameter.

Forgetting to mark the end of the word.

The parameter name and all references inside the function should be consistent, here 'str'.