The partial calculator problem I used in interviews

partial-calculator.rb

#
# We have something called a PartialCalculator in the code
# for calculating some health related parameters.
#
# The PartialCalculator works like this -
#
#  - take an input hash
#  - merge the given data with some standard values
#  - calls a FullCalculator with the values (in the overall method)
#
# It also has a special case where it has to produce a `bp_component`.
# For that, it
#
#  - takes the input hash
#  - merge the given data with some standard values
#  - overrides the standard value of bp with the given value
#
# The invocation could be like this-
#
#  pc = PartialCalculator.new(sbp: 124, dbp: 85, hdl: 55, tcl: 120, bmi: 23)
#  puts pc.overall
#  puts pc.bp_component
#
# [Thanks to Healthi (https://www.healthi.in) where I tried this in interviews]
#
class PartialCalculator

	StandardValues = {
		sbp: 120,
		dbp: 80,
		hdl: 50
	}

	def initialize(data)
		@data = data
		@values = @data.merge!(StandardValues)
	end

	def overall
		FullCalculator.new(@values).calculate
	end

	def bp_component
		@values[:sbp] = @data[:sbp]
		FullCalculator.new(@values).calculate
	end

end