Last active
December 26, 2015 10:49
-
-
Save J-Scag/7139170 to your computer and use it in GitHub Desktop.
Grains TODO for Flatiron School day 23
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| # There once was a wise servant who saved the life of a prince. The king promised to pay whatever the servant could dream up. Knowing that the king loved chess, the servant told the king he would like to have grains of wheat. One grain on the first square of a chess board. Two grains on the next. Four on the third, and so on. | |
| # There are 64 squares on a chessboard. | |
| # Write a program that shows | |
| # - how many grains were on each square, and | |
| # - the total number of grains | |
| # ## For bonus points | |
| # Did you get the tests passing and the code clean? If you want to, these are some additional things you could try: | |
| # * Optimize for speed. | |
| # * Optimize for readability. | |
| # Then please share your thoughts in a comment on the submission. Did this experiment make the code better? Worse? Did you learn anything from it? | |
| class Grains | |
| def square(num) | |
| 2 ** (num-1) | |
| end | |
| def total | |
| total = 0 | |
| 64.times do |num| | |
| total += square(num+1) | |
| end | |
| total | |
| end | |
| end | |
| RSpec.configure do |config| | |
| # Use color in STDOUT | |
| config.color_enabled = true | |
| # Use color not only in STDOUT but also in pagers and files | |
| config.tty = true | |
| # Use the specified formatter | |
| config.formatter = :progress # :progress, :html, :textmate | |
| end | |
| describe Grains do | |
| it 'has square_1' do | |
| Grains.new.square(1).should == 1 | |
| end | |
| it 'has square_2' do | |
| Grains.new.square(2).should == 2 | |
| end | |
| it 'has square_3' do | |
| Grains.new.square(3).should == 4 | |
| end | |
| it 'has square_4' do | |
| Grains.new.square(4).should == 8 | |
| end | |
| it 'has square_16' do | |
| Grains.new.square(16).should == 32768 | |
| end | |
| it 'has square_32' do | |
| Grains.new.square(32).should == 2147483648 | |
| end | |
| it 'has square_64' do | |
| Grains.new.square(64).should == 9223372036854775808 | |
| end | |
| it 'has total_grains' do | |
| Grains.new.total.should == 18446744073709551615 | |
| end | |
| end |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment