Calculate the number of grains of wheat on a chessboard given that the number on each square doubles.
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, with the number of grains doubling on each successive square.
There are 64 squares on a chessboard (where square 1 has one grain, square 2 has two grains, and so on).
Write code that shows:
Did you get the tests passing and the code clean? If you want to, these are some additional things you could try:
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?
The tests expect an error to be reported for out of range inputs.
make chez if you're using ChezScheme or
make guile if you're using GNU Guile.
Sometimes the name for the scheme binary on your system will differ from the defaults.
When this is the case, you'll need to tell make by running
make chez chez=your-chez-binary or
make guile guile=your-guile-binary.
(load "test.scm")at the repl prompt.
grains.scmreloading as you go.
(test)to check your solution.
If some of the test cases fail, you should see the failing input and the expected output.
The failing input is presented as a list because the tests call your solution by
(apply grains input-list).
To learn more about
apply see The Scheme Programming Language -- Chapter 5