Merge pull request #105 from TheAlgorithms/fizz-buzz

Fizz buzz

DIRECTORY.md

@@ -10,6 +10,7 @@
     * [Add Digits](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/add_digits.rb)
     * [Find All Duplicates In An Array](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/find_all_duplicates_in_an_array.rb)
     * [Find The Highest Altitude](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/find_the_highest_altitude.rb)
+    * [Fizz Buzz](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/fizz_buzz.rb)
     * [Get Products Of All Other Elements](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/get_products_of_all_other_elements.rb)
     * [Remove Elements](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/remove_elements.rb)
     * [Sort Squares Of An Array](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/sort_squares_of_an_array.rb)

data_structures/arrays/fizz_buzz.rb

@@ -0,0 +1,102 @@
+# Write a program that outputs the string representation of numbers
+# from 1 to n. But for multiples of three it should output “Fizz”
+# instead of the number and for the multiples of five output “Buzz”.
+# For numbers which are multiples of both three and five output
+# “FizzBuzz”.
+
+#
+# Approach 1: Naive Approach
+#
+
+# Complexity Analysis
+
+# Time Complexity: O(N)
+# Space Complexity: O(1)
+
+# @param {Integer} n
+# @return {String[]}
+def fizz_buzz(n)
+  str = []
+
+  n.times do |i|
+    i += 1
+
+    if i % 5 == 0 && i % 3 == 0
+      str.push('FizzBuzz')
+    elsif i % 3 == 0
+      str.push('Fizz')
+    elsif i % 5 == 0
+      str.push('Buzz')
+    else
+      str.push(i.to_s)
+    end
+  end
+
+  str
+end
+
+n = 15
+fizz_buzz(n)
+# => [
+#     "1",
+#     "2",
+#     "Fizz",
+#     "4",
+#     "Buzz",
+#     "Fizz",
+#     "7",
+#     "8",
+#     "Fizz",
+#     "Buzz",
+#     "11",
+#     "Fizz",
+#     "13",
+#     "14",
+#     "FizzBuzz"
+# ]
+
+#
+# Approach 2: String Concatenation
+#
+
+# Algorithm
+#
+# Instead of checking for every combination of these conditions,
+# check for divisibility by given numbers i.e. 3, 5 as given in the
+# problem. If the number is divisible, concatenate the corresponding
+# string mapping Fizz or Buzz to the current answer string.
+#
+# For eg. If we are checking for the number 15, the steps would be:
+#
+# Condition 1: 15 % 3 == 0 , num_ans_str = "Fizz"
+# Condition 2: 15 % 5 == 0 , num_ans_str += "Buzz"
+# => num_ans_str = "FizzBuzz"
+#
+
+# Complexity Analysis
+#
+# Time Complexity: O(N)
+# Space Complexity: O(1)
+
+# @param {Integer} n
+# @return {String[]}
+def fizz_buzz(n)
+  str = []
+
+  n.times do |i|
+    i += 1
+    num_str = ''
+
+    num_str += 'Fizz' if i % 3 == 0
+    num_str += 'Buzz' if i % 5 == 0
+
+    num_str = i.to_s if num_str == ''
+
+    str.push(num_str)
+  end
+
+  str
+end
+
+n = 15
+puts(fizz_buzz(n))