exercism-80 Largest Series Prodcut

Author: kumar91gopi

README.md

@@ -305,6 +305,7 @@ solution of many challenges of [Leetcode](https://leetcode.com/), [Exercism](htt
 77. [Simple Linked List](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/exercism/simple_linked_list.rb)
 78. [Binary Search Tree](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/exercism/binary_search_tree.rb)
 79. [Rotational Cipher](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/exercism/rotational_cipher.rb)
+80. [Largest Series Product](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/exercism/largest_series_product.rb)
 
 <a name="leetcode"/>
 

exercism/largest_series_product.rb

@@ -0,0 +1,42 @@
+# problem: https://exercism.org/tracks/ruby/exercises/largest-series-product
+
+# Solution(idiomatic ruby- using each_cons)
+class Series
+    def initialize(series)
+      @series = series
+    end
+    def largest_product(span)
+      raise ArgumentError if span<=0 or span>@series.length or !@series.scan(/\D/).empty?
+      max_product =0
+      @series.chars.each_cons(span) do |number|
+        curr_product = 1
+        number.each do |digit|
+          curr_product*=digit.to_i
+        end
+      max_product = max_product >curr_product ? max_product : curr_product
+    end
+      max_product
+    end
+end
+
+# Solution
+class Series
+    def initialize(series)
+      @series = series
+    end
+    
+    def largest_product(span)
+      raise ArgumentError if span<=0 or span>@series.length or !@series.scan(/\D/).empty?
+      max_product =0
+      curr_product = 1
+      for i in 0..(@series.length-span)
+        @series[i...(span+i)].chars.each do |digit|
+          curr_product*= digit.to_i
+        end
+        max_product = max_product>curr_product ? max_product: curr_product
+        curr_product = 1
+      end
+      max_product
+    end
+end
+