adamloo85 · December 28, 2015 17:49 · Nov 19, 2013 · Nov 19, 2013 · Nov 19, 2013 · Nov 19, 2013
diff --git a/pivot.rb b/pivot.rb
@@ -1,4 +1,5 @@
 #README
+#Run by typing "ruby (filename)".  Drive code is already included.
 #This script adds a method "find_pivot" to the array class which finds the pivot point of any array
 #and returns the index of that point if it exists or -1 otherwise.
 

diff --git a/pivot.rb b/pivot.rb
@@ -1,3 +1,7 @@
+#README
+#This script adds a method "find_pivot" to the array class which finds the pivot point of any array
+#and returns the index of that point if it exists or -1 otherwise.
+
 class Array
 	def find_pivot
 		raise NoMethodError, 'Wrong type of input!' if self.class != Array
@@ -24,4 +28,5 @@ def find_pivot
 	end
 end
 
-[1,4,6,3,2].find_pivot
+p "[1,4,6,3,2].find_pivot yields " + "#{[1,4,6,3,2].find_pivot}."
+p "[1,4,6,7,3,2].find_pivot yields " + "#{[1,4,6,7,3,2].find_pivot}."
diff --git a/pivot_finder.rb → pivot.rb b/pivot_finder.rb → pivot.rb
diff --git a/pivot_tests.rb b/pivot_tests.rb
@@ -0,0 +1,16 @@
+require_relative 'pivot.rb'
+require "test/unit"
+
+class FindPivot < Test::Unit::TestCase
+	def test_structure
+		assert_equal Fixnum, [1,2,3,4,5].find_pivot.class
+		assert_raise NoMethodError do
+			"adam".find_pivot
+		end
+	end
+
+	def test_logic
+		assert_equal 2, [1,4,6,3,2].find_pivot
+		assert_equal -1, [1,4,6,7,3,2].find_pivot
+	end
+end
diff --git a/pivot_finder.rb b/pivot_finder.rb
@@ -1,56 +1,27 @@
-require 'rubygems'
-require 'shoulda-context'
-
-def pivot_finder(array)
-	raise NoMethodError, 'Wrong type of input!' if array.class != Array
-
-	low = 0
-	high = array.length - 1
-	mid = (low + high) / 2
-	searches = 0
-
-	until searches == (array.length / 2)
-		searches += 1
-		left_sum = array[low..mid - 1].inject {|sum, i| sum + i}
-		right_sum = array[mid + 1..high].inject{|sum, i| sum + i}
-
-		if left_sum == right_sum
-			return mid
-		elsif right_sum > left_sum
-			mid += 1
-		elsif left_sum > right_sum
-			mid -= 1
-		end
-	end
-	return -1
-end
-
-## Unit Tests
-class FindPivot < Test::Unit::TestCase
-	context "method structure" do
-		should "return a Fixnum" do
-			assert_equal Fixnum, pivot_finder([1,2,3,4,5]).class
-		end
-
-		should "raise error with wrong arguments" do
-			assert_raise NoMethodError do
-				pivot_finder("adam")
+class Array
+	def find_pivot
+		raise NoMethodError, 'Wrong type of input!' if self.class != Array
+
+		low = 0
+		high = self.length - 1
+		mid = (low + high) / 2
+		searches = 0
+
+		until searches == (self.length / 2)
+			searches += 1
+			left_sum = self[low..mid - 1].inject {|sum, i| sum + i}
+			right_sum = self[mid + 1..high].inject{|sum, i| sum + i}
+
+			if left_sum == right_sum
+				return mid
+			elsif right_sum > left_sum
+				mid += 1
+			elsif left_sum > right_sum
+				mid -= 1
 			end
 		end
+		return -1
 	end
+end
 
-	context "method logic" do
-		setup do
-			@has_pivot = [1,4,6,3,2]
-			@no_pivot = [1,4,6,7,3,2]
-		end
-
-		should "return index of pivot point if there is one" do
-			assert_equal 2, pivot_finder(@has_pivot)
-		end
-
-		should "return -1 if there is no pivot point" do
-			assert_equal -1, pivot_finder(@no_pivot)
-		end
-	end
-end
+[1,4,6,3,2].find_pivot
diff --git a/pivot_finder.rb b/pivot_finder.rb
@@ -0,0 +1,56 @@
+require 'rubygems'
+require 'shoulda-context'
+
+def pivot_finder(array)
+	raise NoMethodError, 'Wrong type of input!' if array.class != Array
+
+	low = 0
+	high = array.length - 1
+	mid = (low + high) / 2
+	searches = 0
+
+	until searches == (array.length / 2)
+		searches += 1
+		left_sum = array[low..mid - 1].inject {|sum, i| sum + i}
+		right_sum = array[mid + 1..high].inject{|sum, i| sum + i}
+
+		if left_sum == right_sum
+			return mid
+		elsif right_sum > left_sum
+			mid += 1
+		elsif left_sum > right_sum
+			mid -= 1
+		end
+	end
+	return -1
+end
+
+## Unit Tests
+class FindPivot < Test::Unit::TestCase
+	context "method structure" do
+		should "return a Fixnum" do
+			assert_equal Fixnum, pivot_finder([1,2,3,4,5]).class
+		end
+
+		should "raise error with wrong arguments" do
+			assert_raise NoMethodError do
+				pivot_finder("adam")
+			end
+		end
+	end
+
+	context "method logic" do
+		setup do
+			@has_pivot = [1,4,6,3,2]
+			@no_pivot = [1,4,6,7,3,2]
+		end
+
+		should "return index of pivot point if there is one" do
+			assert_equal 2, pivot_finder(@has_pivot)
+		end
+
+		should "return -1 if there is no pivot point" do
+			assert_equal -1, pivot_finder(@no_pivot)
+		end
+	end
+end