I want to propose a programming challenge. This could be fun for beginners and experienced programmers as well. It is language agnostic. It might even be more about community than the programming part itself. The challenge itself should not take more than an hour. But it shouldn't be so simple that you don't have to put in a little effort. I will propose the first one, and those who participate are welcome to propose the next and as we can agree on it we can go off and knock it out.
Once you see other people's results you can modify your own, or even propose something to make someone else's better or faster or fix a bug that you find.
These can become toy programs for you to have around for testing concepts, and helping to try out other languages.
If you are interested or know someone else who might want to play too share this with them.
I guess we can use this thread to get started, and I guess i am supposed to use a hashtag for something like this so how about #toyprogrammingchallenge
I will try to work in Python at least in the beginning but you are welcome to work in whatever you are comfortable with.
#toyprogrammingchallenge
First challenge:
"Ninety-nine bottles of beer on the wall"
Generate the whole song from "Ninety-nine" to "No". The output should look like :
Ninety-nine bottles of beer on the wall.
Ninety-nine bottles of beer. Take one down,
pass it around... Ninety-eight bottles of beer.
(You know what the middle looks like)
Two bottles of beer on the wall.
Two bottles of beer. Take one down,
pass it around... one bottle of beer.
One bottle of beer on the wall.
One bottle of beer. Take one down,
pass it around... No bottles of beer.
I won't put too many specifics on how you get there, but the output should be words, not numerals :) Try to write clean, maintainable and visually understandable code.
Let see if I am alone or anyone wants to play along. :)
Here is my first attempt total time 48 minutes.
Common Lisp. 14 minutes.
(defun beer (&optional (start 99))
(loop for num = start then next-num
for next-num = (1- num)
for numstr = (if (eql 0 num) "no" (format nil "~r" num)) then next-numstr
for next-numstr = (if (eql 0 next-num) "no" (format nil "~r" next-num))
for bottles = (format nil "bottle~p" num)
for next-bottles = (format nil "bottle~p" next-num)
while (> num 0) do
(unless (eql num start) (terpri))
(format t
"~@(~a~) ~a of beer on the wall,~%~
~a ~a of beer. Take one down,~%~
pass it around... ~@(~a~) ~a of beer.~%"
numstr bottles numstr bottles next-numstr next-bottles)))
@billstclair now I have to install the clisp interpretter. :) I was just hoping I could run it in emacs :) Looks good, but I will have to play with it later!
Lisp FORMAT's "~r" option makes the problem much easier than in most languages, since it converts 99 to "ninety-nine" in one line of code. The code would have been 2 or 3 times as long, had I had to do that myself.
I used LispWorks to test it, but it should work in clisp.
@billstclair were you then able to initcap it?
That's what "~@(...~)" does.
I would have been quicker, but I don't use "~r", "~p" (pluralize), and "~@(...~)" enough to remember them, so had to look them up.
@billstclair installed gcl and clisp, and apparently still I am not smart enough to run it :)
@billstclair Yay, that did it. Is the bottom NIL stylistic or an abberation?
One bottle of beer on the wall,
one bottle of beer. Take one down,
pass it around... No bottles of beer.
NIL <------- That thing right there ?
The function prints its output, to *standard-output*. That's what the first argument, T, to FORMAT does. NIL is the value returned by the function. I suppose I could have instead consed up a string, and returned that.
@billstclair No matter, just trying to understand what I was looking at. I don't run much Lisp (can you tell :) ) So I was just trying to understand what I was looking at.
