String Pattern Matching Naive in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start the outer loop from the first character of the text.

DSA C

for (int i = 0; i <= n - m; i[1]) {
    // pattern matching logic
}

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A++

B--

C+=

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using decrement operator -- causes the loop to run incorrectly.

Using '+=' without a value is invalid syntax.

The outer loop should increment i by 1 each time to check every possible starting position in the text.

2fill in blank

medium

Complete the code to compare characters of the pattern and text inside the inner loop.

DSA C

for (int j = 0; j < m; j++) {
    if (text[i + j] [1] pattern[j]) {
        break;
    }
}

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A>

B==

C!=

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' causes the loop to break on matching characters, which is wrong.

Using '>' or '<' compares ASCII values but is not suitable here.

We break the loop when characters do not match, so the condition should check for inequality.

3fill in blank

hard

Fix the error in the condition that checks if the pattern was found completely.

DSA C

if (j [1] m) {
    printf("Pattern found at index %d\n", i);
}

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A==

B<

C>

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' or '<=' causes false positives before full match.

Using '>' is incorrect because j cannot be greater than m here.

If j equals m, it means all characters matched and the pattern is found.

4fill in blank

hard

Fill both blanks to correctly declare and initialize the lengths of text and pattern.

DSA C

int n = strlen([1]);
int m = strlen([2]);

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Atext

Bpattern

Cstring

Dinput

Attempts:

3 left

💡 Hint

Common Mistakes

Using undefined variables like 'string' or 'input'.

Mixing up text and pattern variables.

We use strlen on the text and pattern strings to get their lengths.

5fill in blank

hard

Fill all three blanks to complete the naive pattern matching function header and variable declarations.

DSA C

void [1](char *[2], char *[3]) {
    int n = strlen(text);
    int m = strlen(pattern);
    // matching logic
}

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

AnaiveSearch

Btext

Cpattern

Dsearch

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect function names like 'search'.

Swapping parameter names or using undefined names.

The function is named naiveSearch and takes text and pattern as parameters.