day14: could be less lines go?

2 files changed, 296 insertions, 13 deletions

diff --git a/day14.go b/day14.go
index c1babe6..a7527e3 100644
--- a/day14.go
+++ b/day14.go
@@ -9,12 +9,138 @@ import (
 	"strings"
 )
 
+const (
+	rock  byte = '#'
+	air   byte = '.'
+	abyss byte = '~'
+)
+
+func abs(n int) int {
+	if n < 0 {
+		return -n
+	}
+	return n
+}
+
 type coord struct {
 	x, y int
 }
 
 type cave struct {
-	scan []byte
+	scan                []byte
+	width, height, xmin int
+}
+
+func (c *cave) stringify() string {
+	cave := ""
+	for i := 0; i < len(c.scan); i += c.height {
+		cave += string(c.scan[i:i+c.height]) + "\n"
+	}
+	return cave
+}
+
+func (c *cave) setCoord(co coord, value byte) {
+	c.scan[(co.x-c.xmin)*c.height+co.y] = value
+}
+
+func (c *cave) getCoord(x, y int) byte {
+	nx, ny := (x-c.xmin)*c.height, y
+	if (x-c.xmin) >= c.width || y >= c.height {
+		return abyss
+	}
+	if nx+ny < 0 {
+		return abyss
+	}
+	return c.scan[nx+ny]
+}
+
+func (c *cave) drawRocks(c1, c2 coord) {
+	draw := func(co coord, x1, x2 int, up func(i int) coord) {
+		dx := x2 - x1
+		di := 1
+		if dx != 0 {
+			if dx < 0 {
+				dx = -dx
+				di = -di
+			}
+			for i := 0; abs(i) < dx+1; i += di {
+				c.setCoord(up(i), rock)
+			}
+		}
+	}
+	draw(c1, c1.x, c2.x, func(i int) coord { return coord{c1.x + i, c1.y} })
+	draw(c1, c1.y, c2.y, func(i int) coord { return coord{c1.x, c1.y + i} })
+}
+
+func (c *cave) rockFormations(rockFormations [][]coord) {
+	for _, r := range rockFormations {
+		for j, co := range r {
+			if j > 0 {
+				c.drawRocks(r[j-1], co)
+			}
+		}
+	}
+}
+
+func (c *cave) newFloor() []byte {
+	floor := make([]byte, c.height)
+	for i := range floor {
+		floor[i] = air
+	}
+	floor[len(floor)-1] = rock
+	return floor
+}
+
+type sand byte
+
+func (s sand) fall(cave *cave, floor bool) bool {
+	co := &coord{500, 0}
+	left, beneath, right := s.options(cave, co.x, co.y)
+	if left != air && beneath != air && right != air {
+		return false
+	}
+	for {
+		left, beneath, right := s.options(cave, co.x, co.y)
+		if beneath == air {
+			co.y++
+			continue
+		}
+		if left == air {
+			co.x--
+			co.y++
+			continue
+		}
+		if right == air {
+			co.x++
+			co.y++
+			continue
+		}
+		if left == abyss || beneath == abyss || right == abyss {
+			if floor {
+				cave.scan = append(cave.newFloor(), cave.scan...)
+				cave.xmin = cave.xmin - 1
+				cave.width = cave.width + 1
+
+				cave.scan = append(cave.scan, cave.newFloor()...)
+				cave.width = cave.width + 1
+				continue
+			}
+			return false
+		}
+
+		if beneath == rock || beneath == byte(s) {
+			cave.setCoord(*co, byte(s))
+			return true
+		}
+	}
+	fmt.Println("Something went wrong")
+	return false
+}
+
+func (s sand) options(cave *cave, x, y int) (byte, byte, byte) {
+	return cave.getCoord(x-1, y+1),
+		cave.getCoord(x, y+1),
+		cave.getCoord(x+1, y+1)
 }
 
 func main() {
@@ -24,12 +150,13 @@ func main() {
 	}
 
 	s := bufio.NewScanner(f)
-	coords := []coord{}
-	xmin, xmax := 1<<31, 0
-	ymin, ymax := 1<<31, 0
+	rockFormations := [][]coord{}
+	xmin, xmax, ymax := 1<<31, 0, 0
 	for s.Scan() {
 		line := s.Text()
-		for _, coordString := range strings.Split(line, "->") {
+		coordStrings := strings.Split(line, "->")
+		coords := make([]coord, len(coordStrings))
+		for i, coordString := range coordStrings {
 			nums := strings.Split(strings.Trim(coordString, " "), ",")
 			x, err := strconv.Atoi(nums[0])
 			if err != nil {
@@ -48,13 +175,42 @@ func main() {
 			if y > ymax {
 				ymax = y
 			}
-			if y < ymin {
-				ymin = y
-			}
-			coords = append(coords, coord{x, y})
+			coords[i] = coord{x, y}
 		}
+		rockFormations = append(rockFormations, coords)
+	}
+
+	width, height := (xmax-xmin)+1, (ymax-0)+1
+	scan := make([]byte, width*height)
+	for i := range scan {
+		scan[i] = air
 	}
-	fmt.Println(coords, xmin, xmax, ymin, ymax)
+	c := &cave{scan, width, height, xmin}
+	c.rockFormations(rockFormations)
 
-	cave := &cave{scan: make([]byte, (xmax-xmin)*(ymax-ymin))}
+	sandCounter := 0
+	var snd sand = 'o'
+	for snd.fall(c, false) {
+		sandCounter++
+	}
+	fmt.Println("Part 1: ", sandCounter)
+
+	correctedHeight := height + 2
+	scan = make([]byte, width*correctedHeight)
+	for i := range scan {
+		scan[i] = air
+	}
+	c = &cave{scan, width, correctedHeight, xmin}
+	floor := []coord{
+		{xmin, correctedHeight - 1},
+		{xmin + width - 1, correctedHeight - 1},
+	}
+	rockFormations = append(rockFormations, floor)
+	c.rockFormations(rockFormations)
+
+	sandCounter = 1
+	for snd.fall(c, true) {
+		sandCounter++
+	}
+	fmt.Println("Part 2: ", sandCounter)
 }
diff --git a/day14.txt b/day14.txt
index 4e87bb5..59a26bb 100644
--- a/day14.txt
+++ b/day14.txt
@@ -1,2 +1,129 @@
-498,4 -> 498,6 -> 496,6
-503,4 -> 502,4 -> 502,9 -> 494,9
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+484,41 -> 484,42 -> 495,42 -> 495,41
+494,51 -> 498,51
+470,158 -> 475,158
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+468,123 -> 468,127 -> 460,127 -> 460,132 -> 474,132 -> 474,127 -> 473,127 -> 473,123
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+458,171 -> 462,171
+473,73 -> 473,77 -> 466,77 -> 466,82 -> 485,82 -> 485,77 -> 477,77 -> 477,73
+492,162 -> 497,162
+494,27 -> 498,27
+471,162 -> 476,162
+480,156 -> 485,156
+498,13 -> 498,17 -> 497,17 -> 497,24 -> 505,24 -> 505,17 -> 502,17 -> 502,13
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+461,165 -> 465,165
+477,70 -> 487,70 -> 487,69
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+473,73 -> 473,77 -> 466,77 -> 466,82 -> 485,82 -> 485,77 -> 477,77 -> 477,73
+462,85 -> 462,88 -> 454,88 -> 454,94 -> 470,94 -> 470,88 -> 466,88 -> 466,85
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+482,37 -> 488,37 -> 488,36
+473,73 -> 473,77 -> 466,77 -> 466,82 -> 485,82 -> 485,77 -> 477,77 -> 477,73
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+464,162 -> 469,162
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+473,173 -> 477,173
+462,85 -> 462,88 -> 454,88 -> 454,94 -> 470,94 -> 470,88 -> 466,88 -> 466,85
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+473,73 -> 473,77 -> 466,77 -> 466,82 -> 485,82 -> 485,77 -> 477,77 -> 477,73
+498,13 -> 498,17 -> 497,17 -> 497,24 -> 505,24 -> 505,17 -> 502,17 -> 502,13
+464,167 -> 468,167
+468,107 -> 468,100 -> 468,107 -> 470,107 -> 470,104 -> 470,107 -> 472,107 -> 472,97 -> 472,107
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+476,154 -> 481,154
+461,173 -> 465,173
+468,123 -> 468,127 -> 460,127 -> 460,132 -> 474,132 -> 474,127 -> 473,127 -> 473,123
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+468,107 -> 468,100 -> 468,107 -> 470,107 -> 470,104 -> 470,107 -> 472,107 -> 472,97 -> 472,107
+494,33 -> 498,33
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+477,70 -> 487,70 -> 487,69
+473,156 -> 478,156
+455,173 -> 459,173
+478,162 -> 483,162
+462,85 -> 462,88 -> 454,88 -> 454,94 -> 470,94 -> 470,88 -> 466,88 -> 466,85
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+467,173 -> 471,173
+498,13 -> 498,17 -> 497,17 -> 497,24 -> 505,24 -> 505,17 -> 502,17 -> 502,13
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+484,41 -> 484,42 -> 495,42 -> 495,41
+497,30 -> 501,30
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+498,13 -> 498,17 -> 497,17 -> 497,24 -> 505,24 -> 505,17 -> 502,17 -> 502,13
+498,13 -> 498,17 -> 497,17 -> 497,24 -> 505,24 -> 505,17 -> 502,17 -> 502,13
+468,123 -> 468,127 -> 460,127 -> 460,132 -> 474,132 -> 474,127 -> 473,127 -> 473,123
+485,162 -> 490,162
+482,37 -> 488,37 -> 488,36
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+491,30 -> 495,30
+468,107 -> 468,100 -> 468,107 -> 470,107 -> 470,104 -> 470,107 -> 472,107 -> 472,97 -> 472,107
+467,169 -> 471,169
+452,171 -> 456,171
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+464,171 -> 468,171
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+484,41 -> 484,42 -> 495,42 -> 495,41
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+468,123 -> 468,127 -> 460,127 -> 460,132 -> 474,132 -> 474,127 -> 473,127 -> 473,123
+474,160 -> 479,160
+500,51 -> 504,51
+494,45 -> 498,45
+461,169 -> 465,169
+468,123 -> 468,127 -> 460,127 -> 460,132 -> 474,132 -> 474,127 -> 473,127 -> 473,123
+488,51 -> 492,51
+458,167 -> 462,167
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+468,107 -> 468,100 -> 468,107 -> 470,107 -> 470,104 -> 470,107 -> 472,107 -> 472,97 -> 472,107
+498,13 -> 498,17 -> 497,17 -> 497,24 -> 505,24 -> 505,17 -> 502,17 -> 502,13
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+466,137 -> 466,138 -> 484,138
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+468,107 -> 468,100 -> 468,107 -> 470,107 -> 470,104 -> 470,107 -> 472,107 -> 472,97 -> 472,107
+468,107 -> 468,100 -> 468,107 -> 470,107 -> 470,104 -> 470,107 -> 472,107 -> 472,97 -> 472,107
+468,107 -> 468,100 -> 468,107 -> 470,107 -> 470,104 -> 470,107 -> 472,107 -> 472,97 -> 472,107
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+468,123 -> 468,127 -> 460,127 -> 460,132 -> 474,132 -> 474,127 -> 473,127 -> 473,123
+498,13 -> 498,17 -> 497,17 -> 497,24 -> 505,24 -> 505,17 -> 502,17 -> 502,13
+467,160 -> 472,160
+468,107 -> 468,100 -> 468,107 -> 470,107 -> 470,104 -> 470,107 -> 472,107 -> 472,97 -> 472,107
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+481,160 -> 486,160
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+497,48 -> 501,48
+491,48 -> 495,48
+455,169 -> 459,169
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+500,33 -> 504,33
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+449,173 -> 453,173
+473,73 -> 473,77 -> 466,77 -> 466,82 -> 485,82 -> 485,77 -> 477,77 -> 477,73
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+470,171 -> 474,171
+477,158 -> 482,158
+468,123 -> 468,127 -> 460,127 -> 460,132 -> 474,132 -> 474,127 -> 473,127 -> 473,123
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+462,120 -> 462,112 -> 462,120 -> 464,120 -> 464,114 -> 464,120 -> 466,120 -> 466,119 -> 466,120 -> 468,120 -> 468,118 -> 468,120 -> 470,120 -> 470,119 -> 470,120
+473,73 -> 473,77 -> 466,77 -> 466,82 -> 485,82 -> 485,77 -> 477,77 -> 477,73
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+473,73 -> 473,77 -> 466,77 -> 466,82 -> 485,82 -> 485,77 -> 477,77 -> 477,73
+466,137 -> 466,138 -> 484,138
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+484,158 -> 489,158
+462,85 -> 462,88 -> 454,88 -> 454,94 -> 470,94 -> 470,88 -> 466,88 -> 466,85
+462,85 -> 462,88 -> 454,88 -> 454,94 -> 470,94 -> 470,88 -> 466,88 -> 466,85
+488,33 -> 492,33
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+462,85 -> 462,88 -> 454,88 -> 454,94 -> 470,94 -> 470,88 -> 466,88 -> 466,85
+480,151 -> 480,145 -> 480,151 -> 482,151 -> 482,150 -> 482,151 -> 484,151 -> 484,144 -> 484,151 -> 486,151 -> 486,148 -> 486,151 -> 488,151 -> 488,142 -> 488,151
+482,64 -> 482,59 -> 482,64 -> 484,64 -> 484,55 -> 484,64 -> 486,64 -> 486,58 -> 486,64 -> 488,64 -> 488,54 -> 488,64 -> 490,64 -> 490,55 -> 490,64
+488,160 -> 493,160
+462,85 -> 462,88 -> 454,88 -> 454,94 -> 470,94 -> 470,88 -> 466,88 -> 466,85