2785-sort-vowels-in-a-string.rb

# frozen_string_literal: true

# 2785. Sort Vowels in a String
# Medium
# https://leetcode.com/problems/sort-vowels-in-a-string

=begin
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.
=end

# @param {String} s
# @return {String}
def sort_vowels(s)
  ans = s.dup
  vowels = []
  vs = Array["A", "E", "I", "O", "U", "a", "e", "i", "o", "u"]

  ans.each_char { |char| vowels << char if vs.include?(char) }
  vowels.sort!

  ans.each_char.with_index do |char, i|
    if vs.include?(char)
      ans[i] = vowels.shift
    end
  end

  ans
end

# **************** #
#       TEST       #
# **************** #

require "test/unit"
class Test_sort_vowels < Test::Unit::TestCase
  def test_
    assert_equal "lEOtcede", sort_vowels("lEetcOde")
    assert_equal "lYmpH", sort_vowels("lYmpH")
  end
end