Word Search in Trie in DSA C++ - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to insert a character into the Trie node's children.

DSA C++

node->children[[1]] = new TrieNode();

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

A'c' - 'a'

B'b' - 'a'

C'z' - 'a'

D'a' - 'a'

Attempts:

3 left

💡 Hint

Common Mistakes

Using character directly without subtracting 'a'.

Using wrong character subtraction causing out of range index.

The character 'b' minus 'a' gives the correct index 1 for the children array.

2fill in blank

medium

Complete the code to check if the current Trie node marks the end of a word.

DSA C++

if (node->[1]) { return true; }

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AwordEnd

BendOfWord

CisEnd

DisWord

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect or undefined flag names.

Checking for null pointer instead of boolean flag.

The standard boolean flag used is 'isEnd' to mark the end of a word in the Trie node.

3fill in blank

hard

Fix the error in the search function to correctly traverse the Trie for each character.

DSA C++

node = node->children[[1]];

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Aword[i] - 'a'

Bword[i]

Ci

D'a'

Attempts:

3 left

💡 Hint

Common Mistakes

Using the character directly as index causing out of bounds.

Using the loop index 'i' as index instead of character mapping.

We must convert the character to an index by subtracting 'a' to access the correct child node.

4fill in blank

hard

Fill both blanks to complete the recursive helper function for word search in Trie.

DSA C++

bool searchHelper(TrieNode* node, const string& word, int [1]) {
    if ([2] == word.size()) return node->isEnd;
    int index = word[[1]] - 'a';
    if (!node->children[index]) return false;
    return searchHelper(node->children[index], word, [1] + 1);
}

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Apos

Bindex

Dlength

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names causing mismatch.

Comparing wrong variable to word size.

The variable 'pos' is used to track the current position in the word for recursion.

5fill in blank

hard

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

DSA C++

void insert(string word) {
    TrieNode* node = root;
    for (int [1] = 0; [2] < word.size(); [3]++) {
        int index = word[[2]] - 'a';
        if (!node->children[index]) {
            node->children[index] = new TrieNode();
        }
        node = node->children[index];
    }
    node->isEnd = true;
}

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

Ai

Dj

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names in loop causing errors.

Incorrect loop increment syntax.

The loop variable 'i' is used consistently for initialization, condition, and increment.