HackMD
1456.Maximum Number of Vowels in a Substring of Given Length
tags: Medium,String,Sliding Window
1456. Maximum Number of Vowels in a Substring of Given Length
題目描述
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'.
範例
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 sconsists of lowercase English letters.- 1 <=
k<=s.length
解答
Python
class Solution:
def maxVowels(self, s: str, k: int) -> int:
vowels = 'aeiou'
count = 0
for i in range(k):
count += s[i] in vowels
ans = count
for i in range(k, len(s)):
count -= s[i - k] in vowels
count += s[i] in vowels
ans = max(ans, count)
return ans
Yen-Chi ChenFri, May 5, 2023
class Solution:
def maxVowels(self, s: str, k: int) -> int:
i, j = 0, 0
vowels = 'aeiou'
max_length = 0
count_vowel = 0
while i < len(s) and j < len(s):
if j - i < k:
if s[j] in vowels:
count_vowel += 1
max_length = max(max_length, count_vowel)
j += 1
else:
if s[i] in vowels:
count_vowel -= 1
i += 1
return max_length
Ron ChenFri, May 5, 2023
TypeScript
function maxVowels(s: string, k: number): number {
let max = 0;
let currentMax = 0;
const vowels = ['a', 'e', 'i', 'o', 'u'];
const queue: string[] = [];
for (let i = 0; i < s.length; i++) {
if (queue.length < k) {
if (vowels.includes(s[i])) currentMax++;
queue.push(s[i]);
} else {
if (vowels.includes(queue.shift()!)) currentMax--;
if (vowels.includes(s[i])) currentMax++;
queue.push(s[i]);
}
if (currentMax > max) max = currentMax;
}
return max;
}
學習了
function maxVowels(s: string, k: number): number {
let max = 0;
let currentMax = 0;
const vowels = ['a', 'e', 'i', 'o', 'u'];
for (let i = 0; i < s.length; i++) {
if (i < k && vowels.includes(s[i])) {
currentMax++;
} else {
if (vowels.includes(s[i])) currentMax++;
if (vowels.includes(s[i - k])) currentMax--;
}
max = Math.max(max, currentMax);
}
return max;
}
SheepFri, May 5, 2023
C#
public int MaxVowels(string s, int k) {
string vowels = "aeiou";
int count = s.Take(k).Count(c => vowels.Contains(c));
int max = 0;
for(int i = k; i < s.Length; i++) {
if (vowels.Contains(s[i])) count++;
if (vowels.Contains(s[i-k])) count--;
max = Math.Max(max, count);
}
return max;
}
JimFri, May 5, 2023
Javascript
function maxVowels(s, k) {
const vowels = ['a', 'e', 'i', 'o', 'u'];
let count = 0;
for (let i = 0; i < k; i++) {
if (vowels.includes(s[i])) count++;
}
let max = count;
for (let i = k; i < s.length; i++) {
if (vowels.includes(s[i])) count++;
if (vowels.includes(s[i - k])) count--;
max = Math.max(max, count);
}
return max;
}
MarsgoatFri, May 5, 2023
