Leetcode

This posts is used to log my leetcode problem solving.

2785. Sort Vowels in a String 2025.09.11

Given a 0-indexed string s, permute s to get a new string t such that:

• All consonants remain in their original places. More formally, if there is an index i with 0 <= i < s.length such that s[i] is a consonant, then t[i] = s[i].
• The vowels must be sorted in the nondecreasing order of their ASCII values. More formally, for pairs of indices i, j with 0 <= i < j < s.length such that s[i] and s[j] are vowels, then t[i] must not have a higher ASCII value than t[j].

Return the resulting string.

The vowels are 'a', 'e', 'i', 'o', and 'u', and they can appear in lowercase or uppercase. Consonants comprise all letters that are not vowels.

Example 1:

Input: s = “lEetcOde”
Output: “lEOtcede”
Explanation: ‘E’, ‘O’, and ’e’ are the vowels in s; ’l’, ’t’, ‘c’, and ’d’ are all consonants. The vowels are sorted according to their ASCII values, and the consonants remain in the same places.

Example 2:

Input: s = “lYmpH”
Output: “lYmpH”
Explanation: There are no vowels in s (all characters in s are consonants), so we return “lYmpH”.

Constraints:

• 1 <= s.length <= 105
• s consists only of letters of the English alphabet in uppercase and lowercase.

Solution

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

class Solution(object):
    def sortVowels(self, s):
        """
        :type s: str
        :rtype: str
        """
        s = list(s)

        vowels = ['A','E','I','O','U','a','e','i','o','u']
        vowel_indice = []
        vowel_counts = [0] * len(vowels)

        for i,char in enumerate(s):
            if char in vowels:
                vowel_counts[vowels.index(char)] += 1
                vowel_indice.append(i)

        for i,char in enumerate(vowels):
            start_index = sum(vowel_counts[:i]) if i else 0
            end_index = sum(vowel_counts[:i+1])
            for idx in range(start_index, end_index):
                s[vowel_indice[idx]] = char

        return "".join(s)