day 08 part2

08/main.go

@@ -9,29 +9,31 @@ import (
 	"git.z1glr.de/advent-of-code-2025/pkg/aoc"
 )
 
-type Point struct {
+type Node struct {
 	X, Y, Z int
-	Parent  *Point
+	root    *Node
 	Size    int
-	id      int
+	ID      int
 }
 
-func (p *Point) DistanceTo(p2 *Point) float64 {
+func (p *Node) DistanceTo(p2 *Node) float64 {
 	return math.Sqrt(float64((p.X-p2.X)*(p.X-p2.X) + (p.Y-p2.Y)*(p.Y-p2.Y) + (p.Z-p2.Z)*(p.Z-p2.Z)))
 }
 
-func (p *Point) GetRoot() *Point {
-	if p.Parent == nil || p.Parent == p {
+func (p *Node) GetRoot() *Node {
+	if p.root == nil {
 		return p
 	} else {
-		return p.Parent.GetRoot()
+		root := p.root.GetRoot()
+		p.root = root
+		return root
 	}
 }
 
-func PointFromString(s string) Point {
+func PointFromString(s string) Node {
 	parts := strings.Split(s, ",")
 
-	return Point{
+	return Node{
 		X:    aoc.ParseInt(parts[0]),
 		Y:    aoc.ParseInt(parts[1]),
 		Z:    aoc.ParseInt(parts[2]),
@@ -41,30 +43,32 @@ func PointFromString(s string) Point {
 
 type Connection struct {
 	Length float64
-	P1, P2 *Point
+	P1, P2 *Node
 }
 
 func do(test bool) (int, int) {
 	rows := aoc.ReadFileRows(test)
 
-	points := make([]Point, len(rows))
+	points := make([]Node, len(rows))
 
 	for ii, rr := range rows {
 		points[ii] = PointFromString(rr)
-		points[ii].id = ii
+		points[ii].ID = ii + 1
 	}
 
 	connections := []Connection{}
 
-	for ii := range points {
-		for jj := range points[ii+1:] {
+	for ii := range points[:len(points)-1] {
+		for jj := ii + 1; jj < len(points); jj++ {
+			// for jj := range points[ii+1:] {
 			p1 := &points[ii]
 			p2 := &points[jj]
+			// p2 := &points[ii+1+jj]
 
 			connections = append(connections, Connection{
 				Length: p1.DistanceTo(p2),
-				P1:     &points[ii],
-				P2:     &points[ii+1+jj],
+				P1:     p1,
+				P2:     p2,
 			})
 		}
 	}
@@ -72,44 +76,31 @@ func do(test bool) (int, int) {
 	// sort distances by length
 	sort.Slice(connections, func(i, j int) bool { return connections[i].Length < connections[j].Length })
 
-	for ii := range connections[:10] {
+	if test {
+		connections = connections[:10]
+	} else {
+		connections = connections[:1000]
+	}
+
+	for ii := range connections {
 		cc := &connections[ii]
-		// if both have no parent, make the first one as the parent
-		if cc.P1.Parent == nil && cc.P2.Parent == nil {
-			cc.P1.Parent = cc.P1
-			cc.P2.Parent = cc.P1
 
-			cc.P1.Size++
+		root1 := cc.P1.GetRoot()
+		root2 := cc.P2.GetRoot()
 
-			// if the second one has no parent, connect it to the first one
-		} else if cc.P2.Parent == nil {
-			cc.P2.Parent = cc.P1
+		if root1 != root2 {
+			root2.root = root1
 
-			cc.P1.GetRoot().Size++
-		} else if cc.P1.Parent == nil {
-			cc.P1.Parent = cc.P2
-
-			cc.P2.GetRoot().Size++
-
-			// both have a parent -> make the parent of p2's root p1
-		} else {
-			p2Root := cc.P2.GetRoot()
-			p2OldSize := p2Root.Size
-
-			cc.P2.GetRoot().Parent = cc.P1.GetRoot()
-
-			cc.P1.GetRoot().Size += p2OldSize
+			root1.Size += root2.Size
 		}
 	}
 
-	roots := []*Point{}
+	roots := []*Node{}
 
 	for ii := range points {
 		pp := &points[ii]
 		if pp.GetRoot() == pp {
 			roots = append(roots, pp)
-
-			fmt.Println(pp.Size)
 		}
 	}