Landon Curt Noll
f46e68740f
We further deprecate the use of twitter. In cases such as historic guidelines and rules, we add a note about using Mastodon. In cases where a tweet URL was used, we replace with an Internet Archive link because twitter has announced that accounts that are not used for a period of time will be deleted. We add a few missing deprecated_twitter information to the author.numbers and author.cvs files. We remove references to twitter handles (after making sure that both author.numbers and author.cvs has the deprecated_twitter information). When the "_README.md_" files have their header information generated by a tool, such deprecated_twitter data will not be present.
Best one-liner
Dave Burton http://snox.net/ioccc
To build:
make
To run:
./prog arg ...
INABIAF - it's not a bug it's a feature :-)
This entry will very likely crash or do something else if you run it without an arg. It might also print strange output with more than one arg.
Try:
./prog 128
./prog_le 128
./prog_be 128
./prog 170
./prog 85
./prog 128 128
./prog 128 128 128
./prog 128 128 128 128
Alternate code:
By default, this code compiles for Little Endian machines. An alternate version is also compiled for Big Endian machines.
Use prog_be as you would prog above.
Judges' remarks:
Can you determine why this shows strange output for ./prog 128 128
and ./prog 128 128 128 128 but not ./prog 128 128 128?
Can you find a pattern here?
What happens if you specify different numbers?
This tiny one-liner is a bit-twiddler's delight! It does all of the work without looping.
To understand how it works, a good place to start is to look at the hex
value that results when the two magic constants are XORed.
Once you've figured out what happens with one set of constants, how can choosing new constants, but using the same computation generate a reversed result?
This code may be tested by:
make test
Author's remarks:
Invoke this with a single non-negative integer less than 256, and a useful transformation occurs.
Rule 2-ish:
Exporting the constants B,I,T,S to the Makefile allows the
code to be compiled for either LE (little-endian) or BE (big-endian)
machines(!!), so they are truly configuration parameters, not logic.
Notes:
One ping argument only. It will segfault on zero arguments, and
display strange results with more than one argument.
Small, non-negative integers only. Useful range is 0 .. 511, sorta, for LE; 0 .. 255 for BE. Bonus points if you can explain why the limits work this way.
ASCII character set, 64-bit long longs are required.
v,a,r,i,a,b,l,e,s_NAME the operation.
No loops, no branches?!?
Compilation:
Compiles cleanly under clang -Wall -Weverything -pedantic, but you need to add
--include stdio.h --include stdlib.h for the printf(3) and atoi(3).
On a little-endian machine:
clang -include stdio.h -include stdlib.h -Wall -Weverything -pedantic -DB=6945503773712347754LL -DI=5859838231191962459LL -DT=0 -DS=7 -o prog prog.c
On a big-endian machine:
clang -include stdio.h -include stdlib.h -Wall -Weverything -pedantic -DB=7091606191627001958LL -DI=6006468689561538903LL -DT=1 -DS=0 -o prog_be prog.c
You might be interested to compile it both ways on the same host, and try:
./prog 1; ./prog_be 1
Copyright and CC BY-SA 4.0 License:
This file is Copyright (c) 2023 by Landon Curt Noll. All Rights Reserved. You are free to share and adapt this file under the terms of this license:
Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
For more information, see: https://creativecommons.org/licenses/by-sa/4.0/