Ampers: Nora Peters

lib/binary_to_decimal.rb

@@ -4,6 +4,46 @@
 # The least significant bit is at index 7.
 # Calculate  and return the decimal value for this binary number using
 # the algorithm you devised in class.
+
+# my_binary_array = [0, 1, 1, 0, 1, 1, 0, 1]
+
 def binary_to_decimal(binary_array)
-  raise NotImplementedError
+  results_array = []
+  results_array << binary_array[7] * (2**0)
+  results_array << binary_array[6] * (2**1)
+  results_array << binary_array[5] * (2**2)
+  results_array << binary_array[4] * (2**3)
+  results_array << binary_array[3] * (2**4)
+  results_array << binary_array[2] * (2**5)
+  results_array << binary_array[1] * (2**6)
+  results_array << binary_array[0] * (2**7)
+  sum = 0
+  results_array.each do |e|
+    sum += e
+  end
+  return sum
+  # raise NotImplementedError
 end
+
+# puts binary_to_decimal(my_binary_array)
+
+# My pseudocode from class:
+# Come up with random 8-bit number made of zeros and ones (ex: 01101101)
+# Starting from the right-most (aka least-significant) digit, take that digit, and multiply it by the result of 2^0, then write down the result
+# Ex: 1 * (2^0) = 1
+# Take the next number to the left, multiply it by the result of 2^1 then write down the result
+# Ex: 0 * (2^1) = 0
+# Take 3rd number from the left, multiply by the result of 2^2, write down result
+# 1 * (2^2) = 4
+# Take 4th number from the left, multiply by the result of 2^3, write down result
+# 1 * (2^3) = 8
+# Take 5th number from the left, multiply by the result of 2^4, write down result
+# 0 * (2^4) = 0
+# Take 6th number from the left, multiply by the result of 2^5, write down result
+# 1 * (2^5) = 32
+# Take 7th number from the left, multiply by the result of 2^6, write down result
+# 1 * (2^6) = 64
+# Take 8th number from the left, multiply by the result of 2^7, write down result
+# 0 * (2^7) = 0
+#  Add up the sum of all the results
+# 1 + 0 + 4 + 8 + 0 + 32 + 64 + 0 = 109