feat: wip on day 12 part 1

cmd/12/shape/shape.go

@@ -0,0 +1,217 @@
+// Package shape provides a model and methods for representing and manipulating shapes
+package shape
+
+import (
+	"fmt"
+	"maps"
+	"slices"
+	"strconv"
+	"strings"
+
+	"github.com/StevanFreeborn/advent-of-code-2025/internal/position"
+)
+
+// shape.GenerateAllVariants() []Shape
+
+type Shape interface {
+	Id() int
+	GetKey() string
+	GenerateVariants() []Shape
+	RotateClockwise() Shape
+	FlipVertically() Shape
+}
+
+type shape struct {
+	id        int
+	positions []position.Position
+}
+
+func From(lines []string) Shape {
+	idStr := strings.TrimSuffix(lines[0], ":")
+	id, _ := strconv.Atoi(idStr)
+
+	positions := []position.Position{}
+
+	for r, line := range lines[1:] {
+		for c, char := range line {
+			if char != '#' {
+				continue
+			}
+
+			position := position.From(r, c)
+			positions = append(positions, position)
+		}
+	}
+
+	return shape{id: id, positions: positions}
+}
+
+func (s shape) GenerateVariants() []Shape {
+	shapes := []Shape{}
+	var current Shape
+	current = s
+	numberOfTransformations := 4
+
+	// Rotate 90 clockwise
+	for range numberOfTransformations {
+		current = current.RotateClockwise()
+		shapes = append(shapes, current)
+	}
+
+	current = s
+
+	// Flip then rotate 90 clockwise
+	for range numberOfTransformations {
+		shapes = append(shapes, current)
+		flipped := current.FlipVertically()
+		shapes = append(shapes, flipped)
+		current = flipped.RotateClockwise()
+	}
+
+	current = s
+
+	// Rotate 90 clockwise then flip
+	for range numberOfTransformations {
+		shapes = append(shapes, current)
+		rotated := current.RotateClockwise()
+		shapes = append(shapes, rotated)
+		current = rotated.FlipVertically()
+	}
+
+	seenShapes := map[string]Shape{}
+
+	for _, s := range shapes {
+		seenShapes[s.GetKey()] = s
+	}
+
+	return slices.Collect(maps.Values(seenShapes))
+}
+
+func (s shape) RotateClockwise() Shape {
+	rotatedPositions := []position.Position{}
+
+	for _, p := range s.positions {
+		rotatedPosition := position.From(p.Column(), -p.Row())
+		rotatedPositions = append(rotatedPositions, rotatedPosition)
+	}
+
+	rotatedShape := shape{
+		id:        s.id,
+		positions: rotatedPositions,
+	}
+
+	return normalize(rotatedShape)
+}
+
+func (s shape) FlipVertically() Shape {
+	flippedPositions := []position.Position{}
+
+	for _, p := range s.positions {
+		flippedPosition := position.From(p.Row(), -p.Column())
+		flippedPositions = append(flippedPositions, flippedPosition)
+	}
+
+	flippedShape := shape{
+		id:        s.id,
+		positions: flippedPositions,
+	}
+
+	return normalize(flippedShape)
+}
+
+func (s shape) GetKey() string {
+	var sb strings.Builder
+
+	for _, p := range s.positions {
+		fmt.Fprintf(&sb, "%d,%d|", p.Row(), p.Column())
+	}
+
+	return sb.String()
+}
+
+func (s shape) Id() int {
+	return s.id
+}
+
+func normalize(s shape) Shape {
+	if len(s.positions) == 0 {
+		return shape{
+			id:        s.id,
+			positions: s.positions,
+		}
+	}
+
+	minRow := s.positions[0].Row()
+	minColumn := s.positions[0].Column()
+
+	for _, p := range s.positions {
+		if p.Row() < minRow {
+			minRow = p.Row()
+		}
+
+		if p.Column() < minColumn {
+			minColumn = p.Column()
+		}
+	}
+
+	nps := []position.Position{}
+
+	for _, p := range s.positions {
+		nr := p.Row() - minRow
+		nc := p.Column() - minColumn
+		np := position.From(nr, nc)
+		nps = append(nps, np)
+	}
+
+	return shape{
+		id:        s.id,
+		positions: nps,
+	}
+}
+
+func (s shape) String() string {
+	if len(s.positions) == 0 {
+		return "(EMPTY SHAPE)"
+	}
+
+	maxRow := 0
+	maxColumn := 0
+
+	for _, p := range s.positions {
+		if p.Row() > maxRow {
+			maxRow = p.Row()
+		}
+
+		if p.Column() > maxColumn {
+			maxColumn = p.Column()
+		}
+	}
+
+	tempGrid := make([][]string, maxRow+1)
+
+	for r := range tempGrid {
+		tempGrid[r] = make([]string, maxColumn+1)
+
+		for c := range tempGrid[r] {
+			tempGrid[r][c] = "."
+		}
+	}
+
+	for _, p := range s.positions {
+		tempGrid[p.Row()][p.Column()] = "#"
+	}
+
+	var shape strings.Builder
+
+	for _, row := range tempGrid {
+		var rowString strings.Builder
+
+		for _, str := range row {
+			rowString.WriteString(str)
+		}
+
+		shape.WriteString(rowString.String() + "\n")
+	}
+
+	return shape.String()
+}

cmd/12/shape/shape_test.go

@@ -0,0 +1,9 @@
+package shape_test
+
+import (
+	"testing"
+)
+
+func TestFrom(t *testing.T) {
+
+}