58 lines
1.8 KiB
Markdown
58 lines
1.8 KiB
Markdown
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# Grains
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Calculate the number of grains of wheat on a chessboard given that the number
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on each square doubles.
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There once was a wise servant who saved the life of a prince. The king
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promised to pay whatever the servant could dream up. Knowing that the
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king loved chess, the servant told the king he would like to have grains
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of wheat. One grain on the first square of a chess board. Two grains on
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the next. Four on the third, and so on.
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There are 64 squares on a chessboard.
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Write code that shows:
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- how many grains were on each square, and
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- the total number of grains
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## For bonus points
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Did you get the tests passing and the code clean? If you want to, these
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are some additional things you could try:
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- Optimize for speed.
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- Optimize for readability.
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Then please share your thoughts in a comment on the submission. Did this
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experiment make the code better? Worse? Did you learn anything from it?
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* * * *
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For installation and learning resources, refer to the
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[exercism help page](http://exercism.io/languages/ruby).
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For running the tests provided, you will need the Minitest gem. Open a
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terminal window and run the following command to install minitest:
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gem install minitest
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If you would like color output, you can `require 'minitest/pride'` in
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the test file, or note the alternative instruction, below, for running
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the test file.
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Run the tests from the exercise directory using the following command:
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ruby grains_test.rb
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To include color from the command line:
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ruby -r minitest/pride grains_test.rb
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## Source
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JavaRanch Cattle Drive, exercise 6 [http://www.javaranch.com/grains.jsp](http://www.javaranch.com/grains.jsp)
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## Submitting Incomplete Solutions
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It's possible to submit an incomplete solution so you can see how others have completed the exercise.
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