2022 Day 24 Complete

2022/day24/input

@@ -0,0 +1,37 @@
+#.####################################################################################################
+#<>^<v<<vv^^v>^^<v>>v.<<^.v<v>>^v>v>>vv<.>>>^^v>^.><^>>v<>>>>v^^^.v^v<>^^v><^vv<vv<>v<^v>><<^.<<^>^<>#
+#>^v<^^>.<v<<^.<<<<^v<^<<><<<v^>^>>>^^>v>^^>v>^><^>^>vv^>vv>.^^<>.>>vv<^>.<<vv<vv<v^^><v<vv^^^<<>v<^>#
+#.^<.>v^>.>>>.<>^><vv>^^v^<<^<>v<v^.vv.>>>vv^<.<v<<<<.<.v<^<^v^>.vv>><<..v>>.v><^>v>^>^>^^><.<^<>>vv>#
+#>v^<<^v>vv<<.>>^<<<><>v>vv.<>v^vv<>v^^.<>vvv>^<<<>v^><>v<^.^^^.<v<^><>^v>>.v<<<^v<>.^v<>>vv<^v^<v>><#
+#.<><<>vv>><>.><<.>><>v>v^v^vv>.^^v>>>^v.><>>>>v^v^<v<><^.v>^v>><<^<>^v>..<<>^<v<^v.>^<>><.<^v^v.^><>#
+#><..v^v><<<v<^v^<<<<><<<>.<><v..<>v<<^^v>^^vvv^<v^v.v^<>v^<<><<v<<^vv>.v><<vv.v<.vvv>..>vv^v<<^<^^^>#
+#<>^>^>.v<>>v^^v>^>v^><v>.>><<>vv^^v>>v<v>><^v><<>>>^.^<v<..<<>.^^<.^>.><<<^v^><v^v>v..^^>^v<^.<v<<<>#
+#>^^.v^v<>.>><>vv>.<>><>>><<>v><.v<^^^<>v>^v><^^<^.v.>>>v>v.vv>v>>v^.>.^>v^^<><vvv>>v>^v^<.v>^.>v><^>#
+#<^<<>..<<v<.v^<v<vv^^.<^^.<>>.vvv>>^.vv<><v.vv^>><>^<<>v.<.^v>v>^><>^^<v<><><>^^.vv<v^<>.>^v>^^v<><>#
+#><.><v>^v><>..v>vv<<v<<.v<<<v^^<vv.<>^<><v.^^v.v<^<<v.v^vv>>^.^v<<v.v<v<.<v^vv>^vv<^>>^vvvv>^^>>^^><#
+#<^<>vvv>^.>v>>.><>><v>^.>v<>v^v^<^<^^><>>v<v<vv>^><^>.^v^v<^^v><>>v^^<<<vvv.^^>>>^><<<^v><>^^^.v<<v>#
+#.^^.<v>>v.>^.v<^.^.^vv^<>>.v>^<>v<v^v>>^v><<vv^^.v>^v>vvv^^^<>^<>^>vv>vvv.<>vv>^<.v>.<>.vv<>>.>vvv<>#
+#<^^<.^>>v><><^v<.<.><<v^v>v>>v>v^.<.v<.v.v<.>><^>^v<<^^<^^^.^.>>.v>^><v<^><<^>^.>^v^^>v^v<>^>^<.>.><#
+#<.^v>>>.v<<<^.v.>v^^<^>v<<v<^>^v^v^.^<>><v^v<<v.<vv<>^v>^v.^><^.v>><>vvv^^<<^>.<v<<<v<>^vv.^v.vv<..<#
+#.v^v>>v^vv^v>v.v<v>v>^<<v^v><..v<<>>vv^<<v><^^<<<<^>v>vv^<^v^vv><.^^<v^<^vv^<<>>v^><v.^^^vvv>^>^>^v>#
+#<>.>^vv<>v^<vv<<^<.^^^.v>^><>><^^>v<<^^>^>.^^<.v><>v<v>^^v>>^>>.>>.<>vv><^^<^<<>><^vv>>v>^^.^><.<vv<#
+#<^>^v^<^<><<^vv>><v^.v<>>.v<v<><>^v^^<<><>v>^v^v>^^^vvv>>v^<v^^v.v.v<>>>v>><>><>>^..v<>><^v^>><.>^<<#
+#<v^^>>^^<^>.<^>>>v<<v.<.^>vv^^><<vvv<>vvvv^<v^<^<<<v<>>^>vv<^<.v<<<>><v<<v>^v>>.<v<vv^.>.><v^vv<>^.>#
+#>>v>^<.>.v<v.<<<<<v.>^>>>.>v<v>.vv^>^>v>^<>^.^^<v>^^>><><v^^.^>..^.>v>^<v<^v^.>v.v.^<><<><<v<<<^>>><#
+#<>v>>.v>.^>^<<><^v<.>^vv.>^.<v.>.>v<<^^>^><vvv>>vv<>^v.<^v<^>><<<<^^v^v<<^^v.<>^<v^>vvv>^<v>><<>^>^<#
+#<><<v<<<.v>^><^.v<>^vv>v><vv.v><v<v^v>^>^^<.>^^^^vv<>v<^.vvv.^v^>>^.v>><v^>.>v^v<.><>.>>v>v<>>>v^<^<#
+#<^<<<v..<>^<v^<>v>v<vv<v^<<.v^<<<^><v^^>><<v>^v.>>^.vv>>^v<.vv^v<^v^.^^.<.vv>>v>>^<^<<.>>><<<<vv^vv<#
+#<><>vv>^.vv><^^>^>^v^><v<>v>.<>>^v^<>^^^^v^v>>v<<<^v^>>^v^v<vv>vv>v>.><<^^>^<><><<<^<v>vv<<<^<>>^^v>#
+#<><<<<v>>v><^>vv<^><><>^<<^^>^.^^><.vvv<^<>^v^v^v>><>^<vv><^>>><.v<^^>>^vvv^^^v<.>vv^v>v^<<>v.^<.>v<#
+#.>>vv<.<vvv^>v^^v>v<v<^^v^^^.v^>>..^<<^^>><^<>v>.>>.<^><v>><><>v^<^^^v^>v^v>^<><<^>><^<..v><>>^<<v<>#
+#>v.>v>v^^v.v<v^<<<<>><>.<^v>^^<>^^>v^^>>..v^.v<>v>^v>..<v>><^<<><v<^<<.>^>^^<^v>.<v^^<>v..>v^v^^..><#
+#<v.><^v<><^^<.>><<>^^<v<v.v><><.<.>^.vv><v.<>^vv><v>>.<><>^^>><vv^^vvv>>v<^^v.><<>><>^^<^><<><>>>>^.#
+#><<v<v^v<<>^<>v<^><><<<><<v<>^<v^.v>>^<^>^^v<><<<v.v><<>>><>.^.>v<v<^^.^.>v>v>^<v>^<<>^>.<^<vv^<.v>>#
+#.v<<<.v<^>>^<>>v<>v.><>^^v>v<vvvv<<>v<<^.v<^^v>.v>^v>^..^<<.<..^>^.<v<.<<<.<vv^<v<>^.v^^><>>>^..^vv>#
+#<>^>>^^v^>>>.>v^v<^^<<v^^><^<><v.^^v^v<>v>>.>><vv><<<><^v.v<>v><><v<.v<>^v>>>^^v<<v<v>^>vv^v>^v>^.<<#
+#><v^<><v<>vvvv.>vvvvv^.<<<><v.><^^v<v><<>^^.<^>v<^v>.^><>>v.<^.<<.^^.>vv<<<<^.>^^v<v^....v>>>><v.><<#
+#<^>.<<^^^<<>.<>v^^^v<<^>>vv<^.<>>v.^v<^^.<v>v<>^^v>>v.^>vv<<<<>vvv<<.^>v<v<.>>v<^v^vv^<^.^>v.>^.>^^<#
+#<><^<v.^><><v^<<><.>>^^>>v><^<^^v>>^>>^>^<>^>v<^><.<>v^<^v^<<<v^.>..<<vvv<>..v^>>>v>v<<>..<>>>vvv><<#
+#<>>vv>v.^v>.^<><>.v..<<^v><v^>v^v>^^><.>>><<^>v<v<>^^^^vv.<>v.vv>>^<^.>^<>.<^>^<<^v^^<v<>v>^>vv>^<>.#
+#<v<>><v^^v.^^^<^v>^>>v>v<>^<v.^^><.<.>><^^<.vvv<<<.vv^>^>^<v^v.>^vv<^>^>vvv^^^.v<<<^^<>v<<><vv^<<<>>#
+####################################################################################################.#

2022/day24/main.go

@@ -0,0 +1,121 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+
+	h "git.bullercodeworks.com/brian/adventofcode/helpers"
+)
+
+func main() {
+	input := h.StdinToStringSlice()
+	part1(input)
+	part2(input)
+}
+
+func part1(input []string) {
+	field, blizzards, start, target := parseInput(input)
+	fmt.Println("# Part 1")
+	fmt.Println(run(field, blizzards, start, target))
+}
+
+func part2(input []string) {
+	field, blizzards, start, target := parseInput(input)
+	fmt.Println("# Part 2")
+	fmt.Println(run(field, blizzards, start, target) +
+		run(field, blizzards, target, start) +
+		run(field, blizzards, start, target))
+}
+
+type Blizzard struct {
+	pos, dir, wrap h.Coordinate
+}
+
+var (
+	U = h.Coordinate{X: 0, Y: -1}
+	D = h.Coordinate{X: 0, Y: 1}
+	L = h.Coordinate{X: -1, Y: 0}
+	R = h.Coordinate{X: 1, Y: 0}
+)
+
+var directions []h.Coordinate = []h.Coordinate{U, D, L, R}
+
+func parseInput(lines []string) (field [][]rune, blizzards []Blizzard, start, target h.Coordinate) {
+	start.X = strings.Index(lines[0], "E")
+	if start.X == -1 {
+		start.X = strings.Index(lines[0], ".")
+	}
+	target.Y = len(lines) - 1
+	target.X = strings.Index(lines[target.Y], ".")
+	for _, line := range lines {
+		line = strings.TrimSpace(line)
+		field = append(field, []rune(line))
+	}
+	for y, row := range field {
+		for x, c := range row {
+			switch c {
+			case '^':
+				blizzards = append(blizzards, Blizzard{
+					h.Coordinate{X: x, Y: y}, U, h.Coordinate{X: x, Y: len(field) - 2},
+				})
+			case 'v':
+				blizzards = append(blizzards, Blizzard{
+					h.Coordinate{X: x, Y: y}, D, h.Coordinate{X: x, Y: 1},
+				})
+			case '<':
+				blizzards = append(blizzards, Blizzard{
+					h.Coordinate{X: x, Y: y}, L, h.Coordinate{X: len(field[0]) - 2, Y: y},
+				})
+			case '>':
+				blizzards = append(blizzards, Blizzard{
+					h.Coordinate{X: x, Y: y}, R, h.Coordinate{X: 1, Y: y},
+				})
+			}
+		}
+	}
+	return
+}
+
+func valid(field [][]rune, pos h.Coordinate) bool {
+	return pos.X >= 0 && pos.X < len(field[0]) && pos.Y >= 0 && pos.Y < len(field)
+}
+
+func run(field [][]rune, blizzards []Blizzard, start, target h.Coordinate) int {
+	minutes := 0
+	currentStep := make(map[h.Coordinate]bool)
+	currentStep[start] = true
+
+	for !currentStep[target] {
+		//update blizzards
+		whereBlizzards := make(map[h.Coordinate]bool)
+		for i, b := range blizzards {
+			bb := b.pos.Add(b.dir)
+			if valid(field, bb) {
+				if field[bb.Y][bb.X] == '#' {
+					blizzards[i].pos = b.wrap
+				} else {
+					blizzards[i].pos = bb
+				}
+			}
+			whereBlizzards[blizzards[i].pos] = true
+		}
+
+		//find new steps
+		newStep := make(map[h.Coordinate]bool)
+		for pos := range currentStep {
+			if !(whereBlizzards[pos]) {
+				newStep[pos] = true
+			}
+			for _, d := range directions {
+				n := pos.Add(d)
+				if valid(field, n) && field[n.Y][n.X] != '#' && !whereBlizzards[n] {
+					newStep[n] = true
+				}
+			}
+		}
+		currentStep = newStep
+		minutes++
+	}
+
+	return minutes
+}

2022/day24/problem

@@ -0,0 +1,366 @@
+                       Advent of Code
+
+     • [About]
+     • [Events]
+     • [Shop]
+     • [Settings]
+     • [Log Out]
+
+   br0xen (AoC++) 41*
+
+                          int y=2022;
+
+     • [Calendar]
+     • [AoC++]
+     • [Sponsors]
+     • [Leaderboard]
+     • [Stats]
+
+   Our sponsors help make Advent of Code possible:
+   Smarty - Join our private leaderboard and solve our
+   puzzles for BIG PRIZES!!! ----------------- Address
+   Validation and Autocomplete, and more!
+
+--- Day 24: Blizzard Basin ---
+
+   With everything replanted for next year (and with
+   elephants and monkeys to tend the grove), you and the
+   Elves leave for the extraction point.
+
+   Partway up the mountain that shields the grove is a
+   flat, open area that serves as the extraction point.
+   It's a bit of a climb, but nothing the expedition can't
+   handle.
+
+   At least, that would normally be true; now that the
+   mountain is covered in snow, things have become more
+   difficult than the Elves are used to.
+
+   As the expedition reaches a valley that must be
+   traversed to reach the extraction site, you find that
+   strong, turbulent winds are pushing small blizzards of
+   snow and sharp ice around the valley. It's a good thing
+   everyone packed warm clothes! To make it across safely,
+   you'll need to find a way to avoid them.
+
+   Fortunately, it's easy to see all of this from the
+   entrance to the valley, so you make a map of the valley
+   and the blizzards (your puzzle input). For example:
+
+ #.#####
+ #.....#
+ #>....#
+ #.....#
+ #...v.#
+ #.....#
+ #####.#
+
+   The walls of the valley are drawn as #; everything else
+   is ground. Clear ground - where there is currently no
+   blizzard - is drawn as .. Otherwise, blizzards are
+   drawn with an arrow indicating their direction of
+   motion: up (^), down (v), left (<), or right (>).
+
+   The above map includes two blizzards, one moving right
+   (>) and one moving down (v). In one minute, each
+   blizzard moves one position in the direction it is
+   pointing:
+
+ #.#####
+ #.....#
+ #.>...#
+ #.....#
+ #.....#
+ #...v.#
+ #####.#
+
+   Due to conservation of blizzard energy, as a blizzard
+   reaches the wall of the valley, a new blizzard forms on
+   the opposite side of the valley moving in the same
+   direction. After another minute, the bottom
+   downward-moving blizzard has been replaced with a new
+   downward-moving blizzard at the top of the valley
+   instead:
+
+ #.#####
+ #...v.#
+ #..>..#
+ #.....#
+ #.....#
+ #.....#
+ #####.#
+
+   Because blizzards are made of tiny snowflakes, they
+   pass right through each other. After another minute,
+   both blizzards temporarily occupy the same position,
+   marked 2:
+
+ #.#####
+ #.....#
+ #...2.#
+ #.....#
+ #.....#
+ #.....#
+ #####.#
+
+   After another minute, the situation resolves itself,
+   giving each blizzard back its personal space:
+
+ #.#####
+ #.....#
+ #....>#
+ #...v.#
+ #.....#
+ #.....#
+ #####.#
+
+   Finally, after yet another minute, the rightward-facing
+   blizzard on the right is replaced with a new one on the
+   left facing the same direction:
+
+ #.#####
+ #.....#
+ #>....#
+ #.....#
+ #...v.#
+ #.....#
+ #####.#
+
+   This process repeats at least as long as you are
+   observing it, but probably forever.
+
+   Here is a more complex example:
+
+ #.######
+ #>>.<^<#
+ #.<..<<#
+ #>v.><>#
+ #<^v^^>#
+ ######.#
+
+   Your expedition begins in the only non-wall position in
+   the top row and needs to reach the only non-wall
+   position in the bottom row. On each minute, you can
+   move up, down, left, or right, or you can wait in
+   place. You and the blizzards act simultaneously, and
+   you cannot share a position with a blizzard.
+
+   In the above example, the fastest way to reach your
+   goal requires 18 steps. Drawing the position of the
+   expedition as E, one way to achieve this is:
+
+ Initial state:
+ #E######
+ #>>.<^<#
+ #.<..<<#
+ #>v.><>#
+ #<^v^^>#
+ ######.#
+
+ Minute 1, move down:
+ #.######
+ #E>3.<.#
+ #<..<<.#
+ #>2.22.#
+ #>v..^<#
+ ######.#
+
+ Minute 2, move down:
+ #.######
+ #.2>2..#
+ #E^22^<#
+ #.>2.^>#
+ #.>..<.#
+ ######.#
+
+ Minute 3, wait:
+ #.######
+ #<^<22.#
+ #E2<.2.#
+ #><2>..#
+ #..><..#
+ ######.#
+
+ Minute 4, move up:
+ #.######
+ #E<..22#
+ #<<.<..#
+ #<2.>>.#
+ #.^22^.#
+ ######.#
+
+ Minute 5, move right:
+ #.######
+ #2Ev.<>#
+ #<.<..<#
+ #.^>^22#
+ #.2..2.#
+ ######.#
+
+ Minute 6, move right:
+ #.######
+ #>2E<.<#
+ #.2v^2<#
+ #>..>2>#
+ #<....>#
+ ######.#
+
+ Minute 7, move down:
+ #.######
+ #.22^2.#
+ #<vE<2.#
+ #>>v<>.#
+ #>....<#
+ ######.#
+
+ Minute 8, move left:
+ #.######
+ #.<>2^.#
+ #.E<<.<#
+ #.22..>#
+ #.2v^2.#
+ ######.#
+
+ Minute 9, move up:
+ #.######
+ #<E2>>.#
+ #.<<.<.#
+ #>2>2^.#
+ #.v><^.#
+ ######.#
+
+ Minute 10, move right:
+ #.######
+ #.2E.>2#
+ #<2v2^.#
+ #<>.>2.#
+ #..<>..#
+ ######.#
+
+ Minute 11, wait:
+ #.######
+ #2^E^2>#
+ #<v<.^<#
+ #..2.>2#
+ #.<..>.#
+ ######.#
+
+ Minute 12, move down:
+ #.######
+ #>>.<^<#
+ #.<E.<<#
+ #>v.><>#
+ #<^v^^>#
+ ######.#
+
+ Minute 13, move down:
+ #.######
+ #.>3.<.#
+ #<..<<.#
+ #>2E22.#
+ #>v..^<#
+ ######.#
+
+ Minute 14, move right:
+ #.######
+ #.2>2..#
+ #.^22^<#
+ #.>2E^>#
+ #.>..<.#
+ ######.#
+
+ Minute 15, move right:
+ #.######
+ #<^<22.#
+ #.2<.2.#
+ #><2>E.#
+ #..><..#
+ ######.#
+
+ Minute 16, move right:
+ #.######
+ #.<..22#
+ #<<.<..#
+ #<2.>>E#
+ #.^22^.#
+ ######.#
+
+ Minute 17, move down:
+ #.######
+ #2.v.<>#
+ #<.<..<#
+ #.^>^22#
+ #.2..2E#
+ ######.#
+
+ Minute 18, move down:
+ #.######
+ #>2.<.<#
+ #.2v^2<#
+ #>..>2>#
+ #<....>#
+ ######E#
+
+   What is the fewest number of minutes required to avoid
+   the blizzards and reach the goal?
+
+   Your puzzle answer was 240.
+
+--- Part Two ---
+
+   As the expedition reaches the far side of the valley,
+   one of the Elves looks especially dismayed:
+
+   He forgot his snacks at the entrance to the valley!
+
+   Since you're so good at dodging blizzards, the Elves
+   humbly request that you go back for his snacks. From
+   the same initial conditions, how quickly can you make
+   it from the start to the goal, then back to the start,
+   then back to the goal?
+
+   In the above example, the first trip to the goal takes
+   18 minutes, the trip back to the start takes 23
+   minutes, and the trip back to the goal again takes 13
+   minutes, for a total time of 54 minutes.
+
+   What is the fewest number of minutes required to reach
+   the goal, go back to the start, then reach the goal
+   again?
+
+   Your puzzle answer was 717.
+
+   Both parts of this puzzle are complete! They provide
+   two gold stars: **
+
+   At this point, you should return to your Advent
+   calendar and try another puzzle.
+
+   If you still want to see it, you can get your puzzle
+   input.
+
+   You can also [Shareon Twitter Mastodon] this puzzle.
+
+References
+
+   Visible links
+   . https://adventofcode.com/
+   . https://adventofcode.com/2022/about
+   . https://adventofcode.com/2022/events
+   . https://teespring.com/stores/advent-of-code
+   . https://adventofcode.com/2022/settings
+   . https://adventofcode.com/2022/auth/logout
+   . Advent of Code Supporter
+	https://adventofcode.com/2022/support
+   . https://adventofcode.com/2022
+   . https://adventofcode.com/2022
+   . https://adventofcode.com/2022/support
+   . https://adventofcode.com/2022/sponsors
+   . https://adventofcode.com/2022/leaderboard
+   . https://adventofcode.com/2022/stats
+   . https://adventofcode.com/2022/sponsors
+   . https://www.smarty.com/advent-of-code
+   . https://adventofcode.com/2022
+   . https://adventofcode.com/2022/day/24/input
+   . https://twitter.com/intent/tweet?text=I%27ve+completed+%22Blizzard+Basin%22+%2D+Day+24+%2D+Advent+of+Code+2022&url=https%3A%2F%2Fadventofcode%2Ecom%2F2022%2Fday%2F24&related=ericwastl&hashtags=AdventOfCode
+   . javascript:void(0);

2022/day24/testinput

@@ -0,0 +1,7 @@
+#.#####
+#.....#
+#>....#
+#.....#
+#...v.#
+#.....#
+#####.#

2022/day24/testinput2

@@ -0,0 +1,6 @@
+#.######
+#>>.<^<#
+#.<..<<#
+#>v.><>#
+#<^v^^>#
+######.#

helpers/coordinate.go

@@ -38,6 +38,12 @@ func (c *Coordinate) MoveNW() {
 	c.X--
 	c.Y--
 }
+func (c Coordinate) Add(o Coordinate) Coordinate {
+	return Coordinate{
+		X: c.X + o.X,
+		Y: c.Y + o.Y,
+	}
+}
 
 func (c Coordinate) North() Coordinate {
 	return Coordinate{X: c.X, Y: c.Y - 1}