feat: solve day 8 part 1...twice

cmd/08/box/box.go

@@ -0,0 +1,59 @@
+// Package box provides a model and methods for junction boxes.
+package box
+
+import (
+	"math"
+	"strconv"
+	"strings"
+)
+
+type Box interface {
+	Y() int
+	X() int
+	Z() int
+	DistanceFrom(neighbor Box) float64
+}
+
+type box struct {
+	x int
+	y int
+	z int
+}
+
+func (b box) X() int {
+	return b.x
+}
+
+func (b box) Y() int {
+	return b.y
+}
+
+func (b box) Z() int {
+	return b.z
+}
+
+func (b box) DistanceFrom(neighbor Box) float64 {
+	xDiff := math.Pow(float64(b.x-neighbor.X()), 2)
+	yDiff := math.Pow(float64(b.y-neighbor.Y()), 2)
+	zDiff := math.Pow(float64(b.z-neighbor.Z()), 2)
+
+	return math.Sqrt(xDiff + yDiff + zDiff)
+}
+
+func From(str string) Box {
+	parts := strings.Split(str, ",")
+
+	if len(parts) != 3 {
+		panic("invalid junction box")
+	}
+
+	x, _ := strconv.Atoi(parts[0])
+	y, _ := strconv.Atoi(parts[1])
+	z, _ := strconv.Atoi(parts[2])
+
+	return box{
+		x: x,
+		y: y,
+		z: z,
+	}
+}

cmd/08/box/box_test.go

@@ -0,0 +1,46 @@
+package box_test
+
+import (
+	"testing"
+
+	"github.com/StevanFreeborn/advent-of-code-2025/cmd/08/box"
+)
+
+func TestFrom(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected box.Box
+	}{
+		{"1,2,3", box.From("1,2,3")},
+		{"0,0,0", box.From("0,0,0")},
+		{"-1,-2,-3", box.From("-1,-2,-3")},
+	}
+
+	for _, test := range tests {
+		result := box.From(test.input)
+
+		if result != test.expected {
+			t.Errorf("From(%q) = %v; want %v", test.input, result, test.expected)
+		}
+	}
+}
+
+func TestDistanceFrom(t *testing.T) {
+	tests := []struct {
+		box1     box.Box
+		box2     box.Box
+		expected float64
+	}{
+		{box.From("0,0,0"), box.From("1,1,1"), 1.7320508075688772},
+		{box.From("1,2,3"), box.From("4,5,6"), 5.196152422706632},
+		{box.From("-1,-2,-3"), box.From("1,2,3"), 7.483314773547883},
+	}
+
+	for _, test := range tests {
+		result := test.box1.DistanceFrom(test.box2)
+
+		if result != test.expected {
+			t.Errorf("DistanceFrom(%v, %v) = %v; want %v", test.box1, test.box2, result, test.expected)
+		}
+	}
+}