Leaves - Katie Kennedy

lib/binary_to_decimal.rb

@@ -5,5 +5,25 @@
 # Calculate  and return the decimal value for this binary number using
 # the algorithm you devised in class.
 def binary_to_decimal(binary_array)
-  raise NotImplementedError
+  array = binary_array
+  power = 7
+  decimal_value = 0
+  array.each do |bit|
+    decimal_value += bit * (2 ** power)
+    power -= 1
+  end
+  return decimal_value
+  #raise NotImplementedError
+end
+
+def decimal_to_binary(decimal_number)
+  number = decimal_number
+  binary_num = []
+  while number > 1
+    mod = number % 2
+    binary_num.push(mod)
+    number = (number - mod)/2
+  end
+  binary_num.push(number)
+  return binary_num
 end

test/binary_to_decimal_test.rb

@@ -6,28 +6,41 @@
   it "From 10011001 to 153" do
     binary_array = [1, 0, 0, 1, 1, 0, 0, 1]
     expected_decimal = 153
-
+    
     binary_to_decimal(binary_array).must_equal expected_decimal
   end
-
+  
   it "From 00001101 to 13" do
     binary_array = [0, 0, 0, 0, 1, 1, 0, 1]
     expected_decimal = 13
-
+    
     binary_to_decimal(binary_array).must_equal expected_decimal
   end
-
+  
   it "From 10000000 to 128" do
     binary_array = [1, 0, 0, 0, 0, 0, 0, 0]
     expected_decimal = 128
-
+    
     binary_to_decimal(binary_array).must_equal expected_decimal
   end
-
+  
   it "From random binary to decimal" do
     binary_array = Array.new(8) { rand(0..1) }
     expected_decimal = binary_array.join.to_s.to_i(2)
-
+    
     binary_to_decimal(binary_array).must_equal expected_decimal
   end
-end
+
+  it "From 17 to 10001" do
+    decimal = 17
+    expected_binary = [1, 0, 0, 0, 1]
+    decimal_to_binary(decimal).must_equal expected_binary
+  end
+
+  it "From 45 to 101101" do
+    decimal = 45
+    expected_binary = [1, 0, 1, 1, 0, 1]
+    decimal_to_binary(decimal).must_equal expected_binary
+  end
+
+end