AoC 2018 Day 3: Regionification

2018-12-03

Source: No Matter How You Slice It

Part 1: Given a list of overlapping regions defined by (left, top, width, height) count how many integer points occur in more than one region.

AoC 2018 Day 2: Counting letters

2018-12-02

Source: Inventory Management System

Part 1: Given a list of strings, count how many contain exactly two of a letter (a) and how many contain exactly three of a letter (b). Calculate a*b.

AoC 2018 Day 1: Sum-thing to start with

2018-12-01

Source: Chronal Calibration

Part 1: Given a list of numbers (positive and negative) calculate the sum.

Advent of Code 2018

2018-12-01

Let’s do it again! I’m starting a day late, but much better than last year 😄!

This time around, I’m hoping to solve each problem in both Python and Racket, both to show an example of how the languages differ and … well, because I can 😇.

EDIT 2018-12-05: Yeah… I’m not actually going to do these in both Racket and Python. The solutions are ending up being near direct translations. Since there are probably fewer people solving these in Racket, I’ll do that first and Python eventually™.

As always, these problems are wonderful to try to solve yourself. If you agree, stop reading now. This post isn’t going anywhere.

If you’d like to see the full form of any particular solution, you can do so on GitHub (including previous years and possibly some I haven’t written up yet): jpverkamp/advent-of-code

Advent of Code 2017

2018-01-08

As I did with last year / yesterday, I’ve written up a series of posts for the Advent of Code 2017 problems. Again, I didn’t manage to write them up as I did them, but this time around I least I finished mostly on time.

Advent of Code 2016

2018-01-03

As I did last year, I’m going to solve the Advent of Code problems again this year.

Or that was the plan. It turns out that instead I put down my blog for almost a year and a half and never quite got around to doing these problems. So I’m actually backdating these posts from the early days of 2018 to where they would have been had I solved them on time. They’re still interesting problems, so give them a read.

AoC 2017 Day 25: Turing

2017-12-25

Source: The Halting Problem

Part 1: Implement a Turing machine defined as such:

Begin in state A. Perform a diagnostic checksum after 6 steps.

In state A: If the current value is 0: - Write the value 1. - Move one slot to the right. - Continue with state B. If the current value is 1: - Write the value 0. - Move one slot to the left. - Continue with state B.

…

AoC 2017 Day 24: Maker Of Bridges

2017-12-24

Source: Electromagnetic Moat

Part 1: Given a series of reversible components of the form 3/4 (can connect a 3 on one end to a 4 on the other), form a bridge of components. The bridge’s strength is equal to the sum of component values. So 0/3, 3/7, and 7/4 has a strength of 0+3 + 3+7 + 7+4 = 24.

What is the strongest possible bridge?

AoC 2017 Day 23: Duetvmc

2017-12-23

Source: Coprocessor Conflagration

Part 1: Create a variation of the previous DuetVM with only the following four instructions:

set X Y sets register X to Y
sub X Y set register X to X - Y
mul X Y sets register X to X * Y
jnz X Y jumps with an offset of the value of Y, iff X is not equal to zero

If you run the given program, how many times is mul invoked?

AoC 2017 Day 22: Langton's Ant

2017-12-22

Source: Sporifica Virus

Part 1: Implement a cellular automaton on an infinite grid of . and # pixels such that:

Start at (0, 0), facing Up
Repeat:
If the cursor is on . swap it to # and turn Left
If the cursor is on # swap it to . and turn Right
Either way, after turning, move forward once

After 10,000 iterations, how many pixels were turned from . to #?