AoC 2016 Day 2: Pin Typer

2016-12-02

Source: Bathroom Security

Part 1: Take a keypad with the following layout:

1 2 3 4 5 6 7 8 9


> Using the instructions UDLR for Up, Down, Left, and Right respectively, move a 'finger' around over the keypad. At the end of each line of instructions, output the current digit.





First, let's define the grid. We'll use the same trick with complex numbers as [last time]https://blog.jverkamp.com/2016/12/01/aoc-2016-day-1-taxicab-simulator/.

```python
grid = {
    '-1-1j': 1, '+0-1j': 2, '+1-1j': 3,
    '-1+0j': 4, '+0+0j': 5, '+1+0j': 6,
    '-1+1j': 7, '+0+1j': 8, '+1+1j': 9,
}

From there, we can move around the grid, make sure we don’t move off the end, and output a character at the end of each line:

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Advent of Code: Day 24

2015-12-24

Source

Part 1: Split a list of integers into three groups of equal sum. Find the grouping such that the smallest group has the least items, breaking ties by the smallest product for that group.

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Advent of Code: Day 23

2015-12-23

Source

Part 1: Create a simple virtual machine with two registers (a and b, non-negative integers) and six instructions:

  • hlf (a|b) - divide the given register by half, round down
  • tpl (a|b) - triple the given register
  • inc (a|b) - add 1 to the given register
  • jmp [+-]\d+ - jump forward/backwards by the given number of instructions
  • jie (a|b), [+-]\d+ - if the given register is even, jump
  • jio (a|b), [+-]\d+ - if the given register equals one, jump

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Advent of Code: Day 21

2015-12-21

Source

Part 1: Given a shop full of weapons (buy exactly one), armor (buy zero or one), and rings (buy 0, 1, or 2), determine the set of items that will defeat a given enemy for the minimum cost (see the original writeup for more details).

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Advent of Code: Day 20

2015-12-20

Source

Part 1: P(n) is defined such that for each number i, add 10i to any number divisible by i. Find the first value n such that P(n) is at least a given target number.

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