AoC 2016 Day 3: Triangle Validator

2016-12-03

Source: Squares With Three Sides

Part 1: Given a list of sides, determine how many form valid triangles. (Hint: triangle inequality)

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

AoC 2016 Day 1: Taxicab Simulator

2016-12-01

Source: No Time for a Taxicab

Part 1: Starting at 0,0 and given a string of L# / R# to turn left / right and move # squares, where do you end up?

Advent of Code: Day 25

2015-12-25

Source

Part 1: Take the relation:

F(n) = \left\{\begin{matrix} 20151225 & \textrm{if}\ n = 1 \\ 252533F(n-1) \mod 33554393 & \textrm{otherwise} \end{matrix}\right.

Arrange the values according to Cantor's diagonal argument. Find the value at a specific cell.

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.

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

Advent of Code: Day 22

2015-12-22

Source

Part 1: Simulate an RPG mage battle; finding the winning solution using the least mana. See the original writeup for more details.

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).

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.

Advent of Code: Day 19

2015-12-19

Source

Part 1: Given a list of list of string replacements and an input string, determine how many unique output strings are possible after one step.