LeetCode in Kotlin
1456. Maximum Number of Vowels in a Substring of Given Length
Medium
Given a string s and an integer k, return the maximum number of vowel letters in any substring of s with length k.
Vowel letters in English are 'a', 'e', 'i', 'o', and 'u'.
Example 1:
Input: s = “abciiidef”, k = 3
Output: 3
Explanation: The substring “iii” contains 3 vowel letters.
Example 2:
Input: s = “aeiou”, k = 2
Output: 2
Explanation: Any substring of length 2 contains 2 vowels.
Example 3:
Input: s = “leetcode”, k = 3
Output: 2
Explanation: “lee”, “eet” and “ode” contain 2 vowels.
Constraints:
1 <= s.length <= 105sconsists of lowercase English letters.1 <= k <= s.length
Solution
class Solution {
private fun isVowel(c: Char): Boolean {
return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u'
}
fun maxVowels(s: String, k: Int): Int {
var maxVowelCount = 0
var vowelCount = 0
var i = 0
var j = 0
while (j < s.length) {
val c = s[j]
if (isVowel(c)) {
vowelCount++
}
if (j - i + 1 == k) {
maxVowelCount = Math.max(maxVowelCount, vowelCount)
if (isVowel(s[i])) {
vowelCount--
}
i++
}
j++
}
return maxVowelCount
}
}