Grains in C++
Calculate the number of grains of wheat on a chessboard given that the number on each square doubles.
exercism fetch cpp grains
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 code 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?
Make sure you have read the C++ page on exercism.io. This covers the basic information on setting up the development environment expected by the exercises.
Passing the Tests
Get the first test compiling, linking and passing by following the three rules of test-driven development. Create just enough structure by declaring namespaces, functions, classes, etc., to satisfy any compiler errors and get the test to fail. Then write just enough code to get the test to pass. Once you've done that, uncomment the next test by moving the following line past the next test.
This may result in compile errors as new constructs may be invoked that you haven't yet declared or defined. Again, fix the compile errors minimally to get a failing test, then change the code minimally to pass the test, refactor your implementation for readability and expressiveness and then go on to the next test.
Try to use standard C++11 facilities in preference to writing your own low-level algorithms or facilities by hand. CppReference is a wiki reference to the C++ language and standard library. If you are new to C++, but have programmed in C, beware of C traps and pitfalls.
JavaRanch Cattle Drive, exercise 6 http://www.javaranch.com/grains.jsp
Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.