Merge pull request #111 from jsca-kwok/jk-remove-vowels

Add remove vowels from a string algorithm

DIRECTORY.md

@@ -14,6 +14,7 @@
     * [Get Products Of All Other Elements](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/get_products_of_all_other_elements.rb)
     * [Jewels And Stones](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/jewels_and_stones.rb)
     * [Remove Elements](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/remove_elements.rb)
+    * [Remove Vowels](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/remove_vowels.rb)
     * [Richest Customer Wealth](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/richest_customer_wealth.rb)
     * [Shuffle Array](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/shuffle_array.rb)
     * [Single Number](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/single_number.rb)

data_structures/arrays/strings/remove_vowels.rb

@@ -0,0 +1,76 @@
+# Challenge name: Remove vowels from a string
+#
+# Given a string s, remove the vowels 'a', 'e', 'i', 'o', and 'u'
+# from it, and return the new string.
+#
+# Example 1:
+# Input: s = "leetcodeisacommunityforcoders"
+# Output: "ltcdscmmntyfrcdrs"
+#
+# Example 2:
+# Input: s = "aeiou"
+# Output: ""
+#
+# @param {String} s
+# @return {String}
+
+#
+# Approach 1: Brute Force
+#
+# Time Complexity: O(n)
+#
+
+def remove_vowels(s)
+  result_array = []
+  s.downcase!
+  start_array = s.split('')
+
+  start_array.each do |letter|
+    if letter != 'a' && letter != 'e' && letter != 'i' && letter != 'o' && letter != 'u'
+      result_array.push(letter)
+    end
+  end
+
+  result_array.join('')
+end
+
+s = 'leetcodeisacommunityforcoders'
+puts(remove_vowels(s))
+# => "ltcdscmmntyfrcdrs"
+s = 'aeiou'
+puts(remove_vowels(s))
+# => ""
+
+#
+# Approach 2: Regex
+#
+# Time Complexity: O(n)
+#
+def remove_vowels(s)
+  vowels = /[aeiou]/i
+  s.gsub!(vowels, '')
+  s
+end
+
+s = 'leetcodeisacommunityforcoders'
+puts(remove_vowels(s))
+# => "ltcdscmmntyfrcdrs"
+s = 'aeiou'
+puts(remove_vowels(s))
+# => ""
+
+#
+# Approach 3: Using Ruby .delete() method
+#
+# Time Complexity: O(n)
+#
+def remove_vowels(s)
+  s.downcase.delete('aeiou')
+end
+
+s = 'leetcodeisacommunityforcoders'
+puts(remove_vowels(s))
+# => "ltcdscmmntyfrcdrs"
+s = 'aeiou'
+puts(remove_vowels(s))
+# => ""