Phone networks

2014-05-21

Another day, another challenge from /r/dailyprogrammer. It’s almost two weeks old now, but I’ve just now had a chance to get around it.

Your company has built its own telephone network. This allows all your remote locations to talk to each other. It is your job to implement the program to establish calls between locations.

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Novel compression

2014-05-19

Last week on /r/dailyprogrammer, there was a neat trio of posts all about a new compression algorithm:

More specifically, we’re going to represent compressed text with the following rules:

  • If the chunk is just a number (eg. 37), word number 37 from the dictionary (zero-indexed, so 0 is the 1st word) is printed lower-case.
  • If the chunk is a number followed by a caret (eg. 37^), then word 37 from the dictionary will be printed lower-case, with the first letter capitalised.
  • If the chunk is a number followed by an exclamation point (eg. 37!), then word 37 from the dictionary will be printed upper-case.
  • If it’s a hyphen (-), then instead of putting a space in-between the previous and next words, put a hyphen instead.
  • If it’s any of the following symbols: . , ? ! ; : (edit: also ’ and “), then put that symbol at the end of the previous outputted word.
  • If it’s a letter R (upper or lower), print a new line.
  • If it’s a letter E (upper or lower), the end of input has been reached.
  • edit: any other block of text, represent as a literal ‘word’ in the dictionary

Got it? Let’s go!

(If you’d like to follow along: full source)

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Trigonometric Triangle Trouble

2014-05-02

Yesterday’s post at /r/dailyprogrammer managed to pique my interest1:

A triangle on a flat plane is described by its angles and side lengths, and you don’t need all of the angles and side lengths to work out everything about the triangle. (This is the same as last time.) However, this time, the triangle will not necessarily have a right angle. This is where more trigonometry comes in. Break out your trig again, people.

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Gorellian sorting

2014-04-01

It’s been a while, so I figured I should get in a quick coding post. From /r/dailyprogrammer, we have this challenge:

The Gorellians, at the far end of our galaxy, have discovered various samples of English text from our electronic transmissions, but they did not find the order of our alphabet. Being a very organized and orderly species, they want to have a way of ordering words, even in the strange symbols of English. Hence they must determine their own order.

For instance, if they agree on the alphabetical order: UVWXYZNOPQRSTHIJKLMABCDEFG

Then the following words would be in sorted order based on the above alphabet order: WHATEVER ZONE HOW HOWEVER HILL ANY ANTLER COW

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Caesar cipher

2014-03-12

Here’s a 5 minute1 coding challenge from Programming Praxis:

A caeser cipher, named after Julius Caesar, who either invented the cipher or was an early user of it, is a simple substitution cipher in which letters are substituted at a fixed distance along the alphabet, which cycles; children’s magic decoder rings implement a caesar cipher. Non-alphabetic characters are passed unchanged. For instance, the plaintext PROGRAMMINGPRAXIS is rendered as the ciphertext SURJUDPPLQJSUDALV with a shift of 3 positions.

– Source: Wikipedia, public domain

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