Leetcode#1456

Maximum Number of Vowels in a Substring of Given Length

Problem Statement

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 <= 105
• s consists of lowercase English letters.
• 1 <= k <= s.length

Golang Solution

func maxVowels(s string, k int) int {
	n := len(s)

	currentNumOfVowels := 0
	for i := 0; i < k; i++ {
		if isVowel(s[i]) {
			currentNumOfVowels++
		}
	}

	maxNumOfVowels := currentNumOfVowels

	leftIndex := 0
	rightIndex := k - 1

	for rightIndex < n-1 {
		if isVowel(s[leftIndex]) {
			currentNumOfVowels -= 1
		}
		leftIndex++
		rightIndex++
		if isVowel(s[rightIndex]) {
			currentNumOfVowels += 1
		}
		maxNumOfVowels = max(maxNumOfVowels, currentNumOfVowels)
	}

	return maxNumOfVowels
}

func isVowel(letter byte) bool {
	if letter == 'a' || letter == 'e' || letter == 'i' || letter == 'o' || letter == 'u' {
		return true
	}
	return false
}

Output

Input
s = "abciiidef"
k = 3

Output
3

Please visit https: https://codeandalgo.com for more such contents