Anagram Check Techniques in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to compare the lengths of two strings for anagram check.

DSA C

if (strlen(str1) [1] strlen(str2)) {
    return 0; // Not anagrams
}

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A==

B<

C!=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' instead of '!=' causes the function to wrongly reject anagrams.

Using '>' or '<' does not correctly check length equality.

For two strings to be anagrams, their lengths must be equal. If lengths are not equal (using !=), return 0.

2fill in blank

medium

Complete the code to initialize the frequency array for counting characters.

DSA C

int count[256] = {0};
for (int i = 0; i < [1]; i++) {
    count[(unsigned char)str1[i]]++;
    count[(unsigned char)str2[i]]--;
}

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Astrlen(str2)

Bstrlen(str1)

Csizeof(str1)

Dsizeof(str2)

Attempts:

3 left

💡 Hint

Common Mistakes

Using sizeof on a pointer instead of strlen causes wrong loop bounds.

Using strlen(str2) is correct but less consistent here.

We loop through the length of str1 (which equals str2 length) to count characters.

3fill in blank

hard

Fix the error in the condition that checks if all counts are zero after frequency counting.

DSA C

for (int i = 0; i < 256; i++) {
    if (count[i] [1] 0) {
        return 0; // Not anagrams
    }
}

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A!=

B==

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' causes the function to wrongly accept non-anagrams.

Using '>' or '<' does not correctly detect mismatches.

If any count is not zero, the strings are not anagrams, so use '!=' to check.

4fill in blank

hard

Fill all three blanks to complete the sorting-based anagram check.

DSA C

int compare(const void *a, const void *b) {
    return (*(char *)[1] - *(char *)[2]);
}

qsort(str1, [3], sizeof(char), compare);

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Aa

Bb

Cstrlen(str1)

Dstrlen(str2)

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping 'a' and 'b' in subtraction reverses sorting order.

Using strlen(str2) is valid but inconsistent here.

The compare function subtracts the characters pointed by 'a' and 'b'. The qsort length is the string length.

5fill in blank

hard

Fill all three blanks to complete the final anagram check using sorted strings.

DSA C

if (strncmp(str1, str2, [1]) [2] 0) {
    return [3]; // Not anagrams
} else {
    return 1; // Anagrams
}

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

Astrlen(str1)

B!=

C0

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' instead of '!=' causes wrong anagram detection.

Returning 1 on mismatch is incorrect.

Compare the strings up to their length. If strncmp result is not zero, they differ, so return 0.