So far this week we’ve had a pair of related posts at the DailyProgrammer subreddit1:
Basically, if you’re given a string with vowels, take them out. If you’re given one without vowels, put them back in. One of the two is certainly easier than the other2. :)
Another quick one, this time from /r/dailyprogrammer:
Your goal is to write a program that takes in a list of edge-node relationships, and print a directed adjacency matrix for it. Our convention will follow that rows point to columns. Follow the examples for clarification of this convention.
Something was bugging me about my proof from yesterday. If we take another tack on proving Turing completeness, all we would have to prove is that we can simulate SUBLEQ. Since SUBLEQ is Turing complete, that’s all we need–just convert each SUBLEQ into a SUB, JZ, and a JLS. So that means that Tiny as written should be Turing complete.
So how does that work?
Today’s challenge at /r/dailyprogrammer asks to implement an assembler for a small virtual machine. It has only 16 mnemonics which in unique opcodes (each instruction can have multiple forms for if they’re accessing memory or literals), so it’s a simple virtual machine indeed. As a challenge, you’re supposed to write an interesting program (I actually wrote a virtual machine as well to test them). As an even better challenge, we’re supposed to prove that Tiny is Turing complete. Well, let’s get to it!
Yesterday, the daily programmer Subreddit had a post that mirrored a problem I’ve often seen before: the idea that if you follow first links ((With some caveats)) on Wikipedia, you eventually end with Philosophy. For example, if you follow the first links from Molecule, you get the following path:
Molecule → Atom → Matter → Rest Mass → Invariant Mass → Energy → Kinetic Energy → Physics → Natural Philosophy → Philosophy
Today’s intermediate challenge on Reddit’s /r/dailyprogrammer intrigued me somewhat, so I decided to take a crack at it. The basic idea is if you are given a number, try converting it to all bases from 2 to 64 (with a special encoding). Print out any of those that are words.
For example, if you interpret the number 44,269 as a base 16 (Hexadecimal) number, you get the word “aced”. So just how many of these words are there out there?
Here is today’s /r/dailyprogramming challenge: Generate a simple substitution cipher such that the maximum number of words in a given dictionary of six letter words (there are 7,260 of them) are encoded as strings in alphabetical order.
It may be 1 uinal, 15 kin too late for the new baktun, but I’ve got some neat code to convert back and forth between the Gregorian calendar and the Mayan calendar. It’s based on a challenge on a post on the /r/dailyprogrammer subreddit. As one might expect, the goal is to be able to take a year, month, and day in the Gregorian calendar and return the equivalent Mayan Long Count corresponding to that date. As a bonus (which of course I had to do 😄), do the opposite and do it without using built in date functions.