63 lines
2.5 KiB
Markdown
63 lines
2.5 KiB
Markdown
# Grains
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Write a program that calculates the number of grains of wheat on a chessboard given that the number 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 a program 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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## Getting Started
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Make sure you have read the [getting started with C++](http://help.exercism.io/getting-started-with-cpp.html)
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page on the [exercism help site](http://help.exercism.io/). This covers
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the basic information on setting up the development environment expected
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by the exercises.
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## Passing the Tests
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Get the first test compiling, linking and passing by following the [three
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rules of test-driven development](http://butunclebob.com/ArticleS.UncleBob.TheThreeRulesOfTdd).
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Create just enough structure by declaring namespaces, functions, classes,
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etc., to satisfy any compiler errors and get the test to fail. Then write
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just enough code to get the test to pass. Once you've done that,
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uncomment the next test by moving the following line past the next test.
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```C++
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#if defined(EXERCISM_RUN_ALL_TESTS)
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```
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This may result in compile errors as new constructs may be invoked that
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you haven't yet declared or defined. Again, fix the compile errors minimally
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to get a failing test, then change the code minimally to pass the test,
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refactor your implementation for readability and expressiveness and then
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go on to the next test.
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Try to use standard C++11 facilities in preference to writing your own
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low-level algorithms or facilities by hand. [CppReference](http://en.cppreference.com/)
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is a wiki reference to the C++ language and standard library. If you
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are new to C++, but have programmed in C, beware of
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[C traps and pitfalls](http://www.slideshare.net/LegalizeAdulthood/c-traps-and-pitfalls-for-c-programmers).
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## Source
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JavaRanch Cattle Drive, exercise 6 [view source](http://www.javaranch.com/grains.jsp)
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