Count the Number of Vowel Strings in Range Solution
You are given a 0-indexed array of string words
and two integers left
and right
.
A string is called a vowel string if it starts with a vowel character and ends with a vowel character where vowel characters are 'a'
, 'e'
, 'i'
, 'o'
, and 'u'
.
Return the number of vowel strings words[i]
where i
belongs to the inclusive range [left, right]
.
Example 1:Count the Number of Vowel Strings in Range Solution
Input: words = ["are","amy","u"], left = 0, right = 2 Output: 2 Explanation: - "are" is a vowel string because it starts with 'a' and ends with 'e'. - "amy" is not a vowel string because it does not end with a vowel. - "u" is a vowel string because it starts with 'u' and ends with 'u'. The number of vowel strings in the mentioned range is 2.
Example 2:Count the Number of Vowel Strings in Range Solution
Input: words = ["hey","aeo","mu","ooo","artro"], left = 1, right = 4 Output: 3 Explanation: - "aeo" is a vowel string because it starts with 'a' and ends with 'o'. - "mu" is not a vowel string because it does not start with a vowel. - "ooo" is a vowel string because it starts with 'o' and ends with 'o'. - "artro" is a vowel string because it starts with 'a' and ends with 'o'. The number of vowel strings in the mentioned range is 3.
Constraints:Count the Number of Vowel Strings in Range Solution
1 <= words.length <= 1000
1 <= words[i].length <= 10
words[i]
consists of only lowercase English letters.0 <= left <= right < words.length
Solution:Count the Number of Vowel Strings in Range Solution
To solve this problem, we can iterate through the words in the given range [left, right], and for each word, we can check if it starts and ends with a vowel character. If it does, we count it as a vowel string.
Here’s the algorithm:
- Initialize a count variable to 0.
- Iterate over the range [left, right] and for each index i, do the following: a. If the word at index i starts with a vowel character and ends with a vowel character, increment the count.
- Return the count.
We can use the is_vowel() helper function to check if a character is a vowel or not. The function returns True if the character is a vowel and False otherwise.Count the Number of Vowel Strings in Range Solution
Here’s the Python code that implements the above algorithm:
def is_vowel(c):
return c in [‘a’, ‘e’, ‘i’, ‘o’, ‘u’]
def count_vowel_strings(words, left, right):
count = 0
for i in range(left, right+1):
word = words[i]
if is_vowel(word[0]) and is_vowel(word[-1]):
count += 1
return count