Mercurial > hg > aoc
diff 2017/day24/problem @ 34:049fb8e56025
Add problem statements and inputs
author | Jordi Gutiérrez Hermoso <jordigh@octave.org> |
---|---|
date | Tue, 09 Jan 2018 21:51:44 -0500 |
parents | |
children |
line wrap: on
line diff
new file mode 100644 --- /dev/null +++ b/2017/day24/problem @@ -0,0 +1,81 @@ +--- Day 24: Electromagnetic Moat --- + +The CPU itself is a large, black building surrounded by a bottomless +pit. Enormous metal tubes extend outward from the side of the building +at regular intervals and descend down into the void. There's no way to +cross, but you need to get inside. + +No way, of course, other than building a bridge out of the magnetic +components strewn about nearby. + +Each component has two ports, one on each end. The ports come in all +different types, and only matching types can be connected. You take an +inventory of the components by their port types (your puzzle input). +Each port is identified by the number of pins it uses; more pins mean +a stronger connection for your bridge. A 3/7 component, for example, +has a type-3 port on one side, and a type-7 port on the other. + +Your side of the pit is metallic; a perfect surface to connect a +magnetic, zero-pin port. Because of this, the first port you use must +be of type 0. It doesn't matter what type of port you end with; your +goal is just to make the bridge as strong as possible. + +The strength of a bridge is the sum of the port types in each +component. For example, if your bridge is made of components 0/3, 3/7, +and 7/4, your bridge has a strength of 0+3 + 3+7 + 7+4 = 24. + +For example, suppose you had the following components: + +0/2 +2/2 +2/3 +3/4 +3/5 +0/1 +10/1 +9/10 + +With them, you could make the following valid bridges: + + 0/1 + 0/1--10/1 + 0/1--10/1--9/10 + 0/2 + 0/2--2/3 + 0/2--2/3--3/4 + 0/2--2/3--3/5 + 0/2--2/2 + 0/2--2/2--2/3 + 0/2--2/2--2/3--3/4 + 0/2--2/2--2/3--3/5 + +(Note how, as shown by 10/1, order of ports within a component doesn't +matter. However, you may only use each port on a component once.) + +Of these bridges, the strongest one is 0/1--10/1--9/10; it has a +strength of 0+1 + 1+10 + 10+9 = 31. + +What is the strength of the strongest bridge you can make with the +components you have available? + +Your puzzle answer was 1695. + +--- Part Two --- + +The bridge you've built isn't long enough; you can't jump the rest of +the way. + +In the example above, there are two longest bridges: + + 0/2--2/2--2/3--3/4 + 0/2--2/2--2/3--3/5 + +Of them, the one which uses the 3/5 component is stronger; its +strength is 0+2 + 2+2 + 2+3 + 3+5 = 19. + +What is the strength of the longest bridge you can make? If you can +make multiple bridges of the longest length, pick the strongest one. + +Your puzzle answer was 1673. + +Both parts of this puzzle are complete! They provide two gold stars: **