Count Vowel Bookends

Difficulty: ⚫⚫◯◯

Tags: array, strings, counting

Hurdle: Passing this question is sufficient to pass the arrays hurdle.

Description

Write a function count_vowel_bookends that takes an array of strings with exactly size strings. Each string is terminated by the null terminator ('\0') character.

The function should return the count of strings that:

1. Start with a vowel, AND
2. End with a vowel

Vowels: a, e, i, o, u (and their uppercase versions A, E, I, O, U)

Important Rules:

• Both conditions must be met: The string must start AND end with a vowel to be counted.
• Case-insensitive: Both uppercase and lowercase vowels count.
• Empty strings (containing only '\0') should NOT be counted.
• Single character strings: A single vowel like "a" or "I" counts (it both starts and ends with a vowel).

Examples

Example 1: Basic Cases

char *array[] = {
    "apple",      // starts 'a', ends 'e' -> YES
    "banana",     // starts 'b', ends 'a' -> NO (doesn't start with vowel)
    "orange",     // starts 'o', ends 'e' -> YES
    "idea",       // starts 'i', ends 'a' -> YES
};
// Result: 3

Example 2: Uppercase Works Too

char *array[] = {
    "hello",      // starts 'h' -> NO
    "world",      // starts 'w' -> NO
    "APPLE",      // starts 'A', ends 'E' -> YES
    "Olive",      // starts 'O', ends 'e' -> YES (mixed case)
};
// Result: 2

Example 3: Edge Cases

char *array[] = {
    "a",          // single vowel -> YES
    "b",          // single consonant -> NO
    "I",          // single uppercase vowel -> YES
};
// Result: 2

Example 4: All Match

char *array[] = {
    "aardvarke",  // a...e -> YES
    "elite",      // e...e -> YES
    "origami",    // o...i -> YES
};
// Result: 3

Example 5: None Match

char *array[] = {
    "cat",        // c...t -> NO
    "dog",        // d...g -> NO
    "bird",       // b...d -> NO
};
// Result: 0

Example 6: Starts with Vowel but Doesn't End with Vowel

char *array[] = {
    "elephant",   // e...t -> NO (ends with consonant)
    "igloo",      // i...o -> YES
    "under",      // u...r -> NO (ends with consonant)
};
// Result: 1

Function Signature

int count_vowel_bookends(int size, char *array[MAX_ROWS]);

Constants

#define MAX_ROWS 100

Constraints

• You can assume there will be at least one string (size >= 1).
• Each string will have at most 100 characters.
• Strings may be empty (contain only '\0'). Empty strings should NOT be counted.
• Both uppercase and lowercase vowels should be recognized.
• Do not modify the array provided.
• Do not call scanf, getchar, or fgets.
• Do not call printf (the function should only return a value).

Hints

• Create a helper function to check if a character is a vowel.
• Use strlen() to find the length of each string.
• Remember to handle empty strings (length 0).
• The last character of a string is at index length - 1.

Testing

./count-vowel-bookends apple banana orange idea
3

./count-vowel-bookends hello world APPLE Olive
2

./count-vowel-bookends a b I
2

./count-vowel-bookends cat dog bird
0