cslarsen

#|
 | Celsius-Fahrenheit temperature table
 |
 | Taken from
 | http://programmingpraxis.com/2012/09/07/the-first-two-programs/2/
 |
 | Ported to current R7RS scheme by Christian Stigen Larsen
 | Public Domain, 2012
 |
 | Works in Mickey Scheme

cslarsen

/*
 * Simple program I wrote after reading Felix Von Leitner's notes
 * on optimization at http://www.fefe.de/source-code-optimization.pdf
 *
 * In the 90s, it used to be faster to do (x<<8)+(x<<6) than x*320,
 * but today with the Intel Core i7, it's actually faster to do
 * x*320.
 *
 * And the compiler knows it!
 *

cslarsen

/*
 * To compile objective-c on the command line:
 *
 * gcc -framework Foundation objc-gcc.m
 *
 * You may have to link with -lobjc or other libs,
 * as required.
 */

#import <Foundation/Foundation.h>

cslarsen

/*
 * A simple way to format numbers as human readable strings.
 * E.g., 123456789 ==> 123 million
 *
 * Written by Christian Stigen Larsen
 * http://csl.sublevel3.org
 *
 * Placed in the public domain by the author, 2012
 */

cslarsen

"""
Implementation of memoization decorator in Python.

Written by Christian Stigen Larsen
http://csl.sublevel3.org

Put in the public domain by the author, 2012

This is an example of how to use decorators to implement different kind of
behaviour in Python.

cslarsen

/*
 * Reverse string in "canonical" C++
 *
 * Why did I make this a gist?  Because I've seen so
 * many cumbersome ways of doing this in C++, including
 * using <algorithm> and std::reverse, using loops and
 * so on.  Yeah, those work too, and loops are fine for
 * C, but in C++, you should simply just use the iterators
 * and standard constructors that std::string gives you.
 *

cslarsen

/*
 * Euler's totient function phi(n).
 * http://en.wikipedia.org/wiki/Euler%27s_totient_function
 *
 * This is an *EXTREMELY* fast function and uses
 * several tricks to recurse.
 *
 * It assumes you have a list of primes and a fast
 * isprime() function.  Typically, you use a bitset
 * to implement the sieve of Eratosthenes and use

cslarsen

/*
 * The binary gcd algorithm using iteration.
 * Should be fairly fast.
 *
 * Put in the public domain by the author:
 *
 * Christian Stigen Larsen
 * http://csl.sublevel3.org
 */
int binary_gcd(int u, int v)

cslarsen

#!/usr/bin/env python

"""Functions to convert IPv4 address to integer and vice-versa.

Written by Christian Stigen Larsen, http://csl.sublevel3.org
Placed in the public domain by the author, 2012-01-11

Example usage:
$ ./ipv4 192.168.0.1 3232235521
192.168.0.1 ==> 3232235521

cslarsen

/*
 * A simple sieve of Eratosthenes using bitsets, written by Christian Stigen Larsen
 * You are free to use this code for anything (i.e., public domain).
 *
 * This sieve allocates the bitset on the heap, so you can calculate a lot
 * of prime numbers.
 */

#ifndef INC_PRIMES_H
#define INC_PRIMES_H