AoC 2016 Day 17: Md5 Maze

2016-12-17

Source: Two Steps Forward

Part 1: Create a 4x4 grid of rooms with doors Up, Down, Left, and Right from each location. To determine if a door is currently open:

  • Calculate MD5(salt + sequence) where sequence is a string containing any combination of UDLR depending on how you got to this room
  • The first four hex values represent the doors Up, Down, Left, and Right respectively: bcdef means open; anything else is closed

Find the shortest path from (0, 0) to (3, 3).

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AoC 2016 Day 11: Radiation Avoider

2016-12-11

Source: Radioisotope Thermoelectric Generators

Part 1: Input will be a list of the following form:

  • The first floor contains a hydrogen-compatible microchip and a lithium-compatible microchip.
  • The second floor contains a hydrogen generator.
  • The third floor contains a lithium generator.
  • The fourth floor contains nothing relevant.

You have an elevator that can move exactly 1 or 2 items. You can only leave a microchip on a floor with a non-matching generator if a matching generator is also present.

Move all items to the top (4th) floor.

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Takuzu solver

2015-10-29

Based on a /r/dailyprogrammer puzzle: Takuzu solver.

Basically, Takuzu is a logic puzzle similar to Sudoku. You are given a grid partially filled with 0s and 1s. You have to fill in the rest of the grid according to three simple rules:

  • You cannot have more than three of the same number in a line
  • Each column must have an equal number of 0s and 1s1
  • No two rows or no two columns can be identical

Thus, if you have a puzzle like this:

0.01.1
0....1
..00..
..00..
1....0
10.0.0

One valid solution (most puzzles should have only a single valid answer, but that doesn’t always seem to be the case):

010101
001101
110010
010011
101100
101010

Let’s do it!

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Chess Puzzles: N Queens

2014-09-03

After two weeks, it seems only right that we actually get around to a real chess puzzle. First on the list: Eight queens puzzle.

Specifically, how do you place n queens on an n by n chess board such that no pair of queens can attack one another?

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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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