48 lines
No EOL
2.5 KiB
Text
48 lines
No EOL
2.5 KiB
Text
\--- Day 6: Probably a Fire Hazard ---
|
|
----------
|
|
|
|
Because your neighbors keep defeating you in the holiday house decorating contest year after year, you've decided to deploy one million lights in a 1000x1000 grid.
|
|
|
|
Furthermore, because you've been especially nice this year, Santa has mailed you instructions on how to display the ideal lighting configuration.
|
|
|
|
Lights in your grid are numbered from 0 to 999 in each direction; the lights at each corner are at `0,0`, `0,999`, `999,999`, and `999,0`. The instructions include whether to `turn on`, `turn off`, or `toggle` various inclusive ranges given as coordinate pairs. Each coordinate pair represents opposite corners of a rectangle, inclusive; a coordinate pair like `0,0 through 2,2` therefore refers to 9 lights in a 3x3 square. The lights all start turned off.
|
|
|
|
To defeat your neighbors this year, all you have to do is set up your lights by doing the instructions Santa sent you in order.
|
|
|
|
For example:
|
|
|
|
* `turn on 0,0 through 999,999` would turn on (or leave on) every light.
|
|
* `toggle 0,0 through 999,0` would toggle the first line of 1000 lights, turning off the ones that were on, and turning on the ones that were off.
|
|
* `turn off 499,499 through 500,500` would turn off (or leave off) the middle four lights.
|
|
|
|
After following the instructions, *how many lights are lit*?
|
|
|
|
Your puzzle answer was `543903`.
|
|
|
|
\--- Part Two ---
|
|
----------
|
|
|
|
You just finish implementing your winning light pattern when you realize you mistranslated Santa's message from Ancient Nordic Elvish.
|
|
|
|
The light grid you bought actually has individual brightness controls; each light can have a brightness of zero or more. The lights all start at zero.
|
|
|
|
The phrase `turn on` actually means that you should increase the brightness of those lights by `1`.
|
|
|
|
The phrase `turn off` actually means that you should decrease the brightness of those lights by `1`, to a minimum of zero.
|
|
|
|
The phrase `toggle` actually means that you should increase the brightness of those lights by `2`.
|
|
|
|
What is the *total brightness* of all lights combined after following Santa's instructions?
|
|
|
|
For example:
|
|
|
|
* `turn on 0,0 through 0,0` would increase the total brightness by `1`.
|
|
* `toggle 0,0 through 999,999` would increase the total brightness by `2000000`.
|
|
|
|
Your puzzle answer was `14687245`.
|
|
|
|
Both parts of this puzzle are complete! They provide two gold stars: \*\*
|
|
|
|
At this point, all that is left is for you to [admire your Advent calendar](/2015).
|
|
|
|
If you still want to see it, you can [get your puzzle input](6/input). |