add day-21 + benchmarks

day-21/internal/pad/dirpad.go

@@ -0,0 +1,106 @@
+package pad
+
+import (
+	"slices"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+)
+
+type Dirpad struct {
+	current   node
+	pad       [][]rune
+	locations map[rune]coords
+}
+
+func NewDirpad() *Dirpad {
+	pad := [][]rune{
+		{'.', '^', 'A'},
+		{'<', 'v', '>'},
+	}
+	locations := make(map[rune]coords)
+	for y, row := range pad {
+		for x, value := range row {
+			locations[value] = coords{x, y}
+		}
+	}
+
+	return &Dirpad{
+		current:   newNode(2, 0, 'A'),
+		pad:       pad,
+		locations: locations,
+	}
+}
+
+func (dp *Dirpad) valueAt(c coords) rune {
+	return dp.pad[c.y][c.x]
+}
+
+func (dp *Dirpad) nextTarget(c rune) node {
+	coords := dp.locations[c]
+	return newNode(coords.x, coords.y, c)
+}
+
+func (dp *Dirpad) Generate(code string) string {
+	var sb strings.Builder
+	for _, c := range code {
+		target := dp.nextTarget(c)
+		moved := newMove(dp.current.x, target.x, dp.current.y, target.y)
+
+		var hb, vb strings.Builder
+
+		for range absInt(moved.x) {
+			if moved.x >= 0 {
+				hb.WriteRune('>')
+			} else {
+				hb.WriteRune('<')
+			}
+		}
+
+		for range absInt(moved.y) {
+			if moved.y <= 0 {
+				vb.WriteRune('^')
+			} else {
+				vb.WriteRune('v')
+			}
+		}
+
+		if dp.valueAt(coords{dp.current.x + moved.x, dp.current.y}) == '.' {
+			sb.WriteString(vb.String())
+			sb.WriteString(hb.String())
+		} else if dp.valueAt(coords{dp.current.x, dp.current.y + moved.y}) == '.' {
+			sb.WriteString(hb.String())
+			sb.WriteString(vb.String())
+		} else if moved.x < 0 {
+			sb.WriteString(hb.String())
+			sb.WriteString(vb.String())
+		} else if moved.x >= 0 {
+			sb.WriteString(vb.String())
+			sb.WriteString(hb.String())
+		}
+
+		sb.WriteRune('A')
+		dp.current = target
+	}
+
+	log.Tracef("\n%s\n", dp.trace(sb.String()))
+
+	return sb.String()
+}
+
+func (dp *Dirpad) trace(visited string) string {
+	log.Debug(visited)
+	temp := slices.Clone(dp.pad)
+
+	next := coords{2, 0}
+	for _, c := range visited {
+		next = neighbours(next, c)
+		temp[next.y][next.x] = 'X'
+	}
+
+	output := []string{}
+	for _, row := range temp {
+		output = append(output, string(row))
+	}
+	return strings.Join(output, "\n")
+}

day-21/internal/pad/move.go

@@ -0,0 +1,12 @@
+package pad
+
+type move struct {
+	x, y int
+}
+
+func newMove(x1, x2, y1, y2 int) *move {
+	return &move{
+		x: x2 - x1,
+		y: y2 - y1,
+	}
+}

day-21/internal/pad/neighbours.go

@@ -0,0 +1,16 @@
+package pad
+
+func neighbours(c coords, r rune) coords {
+	switch r {
+	case '^':
+		return coords{c.x, c.y - 1}
+	case '>':
+		return coords{c.x + 1, c.y}
+	case 'v':
+		return coords{c.x, c.y + 1}
+	case '<':
+		return coords{c.x - 1, c.y}
+	default:
+		return c
+	}
+}

day-21/internal/pad/node.go

@@ -0,0 +1,14 @@
+package pad
+
+type coords struct {
+	x, y int
+}
+
+type node struct {
+	coords
+	value rune
+}
+
+func newNode(x, y int, value rune) node {
+	return node{coords: coords{x, y}, value: value}
+}

day-21/internal/pad/numpad.go

@@ -0,0 +1,108 @@
+package pad
+
+import (
+	"slices"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+)
+
+type Numpad struct {
+	current   node
+	pad       [][]rune
+	locations map[rune]coords
+}
+
+func NewNumpad() *Numpad {
+	pad := [][]rune{
+		{'7', '8', '9'},
+		{'4', '5', '6'},
+		{'1', '2', '3'},
+		{'.', '0', 'A'},
+	}
+	locations := make(map[rune]coords)
+	for y, row := range pad {
+		for x, value := range row {
+			locations[value] = coords{x, y}
+		}
+	}
+
+	return &Numpad{
+		current:   newNode(2, 3, 'A'),
+		pad:       pad,
+		locations: locations,
+	}
+}
+
+func (np *Numpad) valueAt(c coords) rune {
+	return np.pad[c.y][c.x]
+}
+
+func (np *Numpad) nextTarget(c rune) node {
+	coords := np.locations[c]
+	return newNode(coords.x, coords.y, c)
+}
+
+func (np *Numpad) Generate(code string) string {
+	var sb strings.Builder
+	for _, c := range code {
+		target := np.nextTarget(c)
+		moved := newMove(np.current.x, target.x, np.current.y, target.y)
+
+		var hb, vb strings.Builder
+
+		for range absInt(moved.x) {
+			if moved.x >= 0 {
+				hb.WriteRune('>')
+			} else {
+				hb.WriteRune('<')
+			}
+		}
+
+		for range absInt(moved.y) {
+			if moved.y <= 0 {
+				vb.WriteRune('^')
+			} else {
+				vb.WriteRune('v')
+			}
+		}
+
+		if np.valueAt(coords{np.current.x + moved.x, np.current.y}) == '.' {
+			sb.WriteString(vb.String())
+			sb.WriteString(hb.String())
+		} else if np.valueAt(coords{np.current.x, np.current.y + moved.y}) == '.' {
+			sb.WriteString(hb.String())
+			sb.WriteString(vb.String())
+		} else if moved.x < 0 {
+			sb.WriteString(hb.String())
+			sb.WriteString(vb.String())
+		} else if moved.x >= 0 {
+			sb.WriteString(vb.String())
+			sb.WriteString(hb.String())
+		}
+
+		sb.WriteRune('A')
+		np.current = target
+	}
+
+	log.Tracef("\n%s\n", np.trace(sb.String()))
+
+	return sb.String()
+}
+
+func (np *Numpad) trace(visited string) string {
+	log.Debug(visited)
+	temp := slices.Clone(np.pad)
+
+	next := coords{2, 3}
+	for _, c := range visited {
+		next = neighbours(next, c)
+		temp[next.y][next.x] = 'X'
+	}
+
+	output := []string{}
+	for _, row := range temp {
+		output = append(output, string(row))
+	}
+	return strings.Join(output, "\n")
+}

day-21/internal/pad/util.go

@@ -0,0 +1,7 @@
+package pad
+
+import "math"
+
+func absInt(n int) int {
+	return int(math.Abs(float64(n)))
+}