Landon Curt Noll
4ee4c731f7
While not strictly necessary, replacing the two ASCII tab characters in the markdown copyright comment makes it easier to detect problematic TAB indentation within markdown files. After this commit, only 90 markdown files have leading ASCII TAB characters. And again, while not strictly necessary, we can consider running expand on those 90 markdown files to see what effect that might have on the HTML files they produce. Replace leading ASCII TAB characters with multiples of 8 ASCII SPACE characters (the default action of the `expand(1)` tool) might have an negative effect on some HTML formatting where **hack-a-round** formatting was attempted to fix broken indentation caused by problematic ASCII TAB characters. Think of this as a baseline for evaluating leading TAB characters within markdown files. TODO: Consider either using `expand(1)` to replace leading ASCII TAB characters with multiples of 8 ASCII SPACE characters AND/OR modifying the appropriate `bin` tool to convert leading ASCII TAB characters into multiples of 8 ASCII SPACE characters.
To build:
make all
To use:
./schweikh1
Try:
To find the day that Easter falls on in the current year and to show all Easter dates from 1582 to 2199:
./try.sh
Judges' remarks:
Look at the source. There is something very odd going on here. Where does the real code come from if everything is a C pre-processor statement?
Clearly this is either the Best Use or the Worst Abuse of the C Preprocessor that the judges have seen this year!
Author's remarks:
What this program does
This program is an implementation of an algorithm that calculates the date of the Sunday following the first full moon after the spring equinox. (Also known as "Easter", defined this way by the Nicaean Concilium in 325 Anno Domini.) The algorithm is attributed to the famous mathematician Carl Friedrich Gauss ["Meyers Handbuch ueber das Weltall" 'Handbook About Space', Meyer, 5th Edition, 1973, p149] and is suitable for anni domini within the Gregorian Calendar, that is, from ad 1582 to ad 2199:
Let J be the year.
If J is from 1582 to 1699, let M be 22, let N be 2
If J is from 1700 to 1799, let M be 23, let N be 3
If J is from 1800 to 1899, let M be 23, let N be 4
If J is from 1900 to 2099, let M be 24, let N be 5
If J is from 2100 to 2199, let M be 24, let N be 6
Let a be the modulus of J divided by 19
Let b be the modulus of J divided by 4
Let c be the modulus of J divided by 7
Let d be the modulus of (19a + M) divided by 30
Let e be the modulus of (2b + 4c + 6d + N) divided by 7
The interesting Sunday is either:
March 22 + d + e or
April d + e - 9 (only one of them is a valid date)
with the following exceptions:
April 26 must always be changed to April 19
April 25 must be changed to April 18 if d is 28 and a is greater than 10
Example:
J = 1962, M = 24, N = 5
a = J % 19 == 5
b = J % 4 == 2
c = J % 7 == 2
d = 119 % 30 == 29
e = 191 % 7 == 2
March 53 is invalid, so the result is April 22 1962.
Why I think this is obfuscated
Apart from the calculation of the Easter date, the definition and
calculation of which are obfuscations in their own right,
obfuscation lurks in many places. Look at those macro identifiers.
What can be more obvious than a program that explicitly mentions the
grammatical constructs it is composed of? If you look at K&RII A.9.3
you will find that a compound statement consists of an opening brace
followed by a declaration list followed by a semicolon followed by a
statement list followed by another semicolon and a closing brace.
Nobody can learn that by heart so I gently remind the reader by
defining a macro that expresses this clearly (line 25). This goes up
to the definition of a translation unit. Unfortunately, due to the
IOCCC's size restrictions, I had to abbreviate some syntactic
elements. ae actually reads "assignment expression". I had to stop
at some arbitrary point, so don't waste your time trying to find out
how preprocessing tokens form type qualifier lists, cast expressions
or direct abstract declarators. Assuming the reader knows about
these easy to remember language elements is justified in my opinion.
The moral:
Try to be as precise as can be and no one will comprehend what you mean.
The formula:
comprehension = 1/(2**precision)
The interpretation:
"Say nothing and everybody will understand."
The -I/usr/include in the build file is needed by gcc on Solaris because
gcc's "fixed" header in gcc-lib/sparc-sun-solaris2.5/2.7.2/include/errno.h
is broken (sort of) because it has two identical extern declarations of errno.
This leads to an error due to the redefinition of main. The -I option makes
sure the working /usr/include/errno.h is found first, which shouldn't cause any
problems on other systems.
Usage:
The program is run without arguments. It prints all dates in order.