exercism 45-50

Author: kumar91gopi

README.md

@@ -263,6 +263,11 @@ solution of many challenges of [Leetcode](https://leetcode.com/), [Exercism](htt
 43. [Anagram](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/exercism/anagram.rb)
 44. [Spiral Matrix](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/exercism/spiral_matrix.rb)
 45. [Sum of Multiples](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/exercism/sum_of_multiples.rb)
+46. [Transpose](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/exercism/transpose.rb)
+47. [Armstrong Numbers](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/exercism/armstrong_numbers.rb)
+48. [Flatten Array](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/exercism/flatten_array.rb)
+49. [Phone Number](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/exercism/phone_number.rb)
+50. [Grains](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/exercism/grains.rb)
 
 <a name="leetcode"/>
 

exercism/armstrong_numbers.rb

@@ -0,0 +1,36 @@
+#Problem : https://exercism.org/tracks/ruby/exercises/armstrong-numbers
+
+#Solution
+class ArmstrongNumbers
+    def self.include?(num)
+      return true if num%10==num
+      n=number_of_digits(num)
+      sum= sum_of_pow(num,n)
+      if sum==num
+        return true
+      else
+        return false
+      end
+    end
+
+    def self.number_of_digits(i)
+      count =0
+     until i==0
+       count +=1
+       i/=10
+     end
+    count
+    end
+
+    def self.sum_of_pow(number,number_of_digits)
+      sum=0
+      for i in 0..number_of_digits
+        j=number%10
+        number/=10
+        sum+=(j**number_of_digits)
+      end
+      sum
+    end     
+end
+
+#Solution 2

exercism/flatten_array.rb

@@ -0,0 +1,24 @@
+#Problem: https://exercism.org/tracks/ruby/exercises/flatten-array
+
+#Solution (idiomatic)
+class FlattenArray
+    def self.flatten(arr)
+      arr.flatten.compact
+    end
+end
+
+#Solution 2 (recursive)
+class FlattenArray
+    def self.flatten(arr)
+      result = []
+      arr.each do |val|
+        if val.is_a?(Array)
+          flat_val = flatten(val)
+          result+=flat_val
+        else
+          result.push(val) unless val.nil?
+        end
+      end
+      result    
+    end
+end

exercism/grains.rb

@@ -0,0 +1,13 @@
+#Problem: https://exercism.org/tracks/ruby/exercises/grains
+
+#Solution
+class Grains
+    def self.square(n)
+      raise ArgumentError if n<=0 or n>64
+      2**(n-1)
+    end
+    
+    def self.total
+      (2**(64))-1
+    end
+end

exercism/phone_number.rb

@@ -0,0 +1,30 @@
+#Problem: https://exercism.org/tracks/ruby/exercises/phone-number
+
+#Solution
+class PhoneNumber
+    def self.clean(number)
+      cleaned_num = number.gsub(/[\D]/,"")
+      num_len = cleaned_num.length
+      return nil if num_len<10 or num_len>11
+      if num_len==11
+        return nil unless cleaned_num[0]=="1"
+        cleaned_num = cleaned_num[1..-1]
+      end
+      return nil unless self.valid_area_and_exchange_code(cleaned_num) 
+      cleaned_num  
+    end
+
+    def self.valid_area_and_exchange_code(num)
+      num[0].to_i >=2 and num[0].to_i <=9 and num[3].to_i >=2 and num[3].to_i <=9
+    end
+end
+
+#Solution 2(Idiomatic)
+class PhoneNumber
+    VALID_PHONE_NUMBER = /^([2-9]\d\d){2}\d{4}$/
+    def self.clean(number)
+      numbers = number.gsub(/\D/, "").sub(/^1/, "")
+      numbers[VALID_PHONE_NUMBER]
+    end
+end
+  

exercism/transpose.rb

@@ -0,0 +1,13 @@
+#Problem: https://exercism.org/tracks/ruby/exercises/transpose
+
+#Solution
+class Transpose
+    def self.transpose(input)
+      strings = input.gsub(' ', '_').split("\n").map(&:chars)
+      max_length = strings.map(&:length).max
+      strings.map { |line| line + ([' '] * (max_length - line.length)) }
+             .transpose
+             .map { |line| line.join.rstrip.gsub('_', ' ') }
+             .join("\n")
+    end
+end