Day 8 part 1 solution.

2018/internal/day08/debug.go

@@ -0,0 +1,25 @@
+package day08
+
+import (
+	"fmt"
+)
+
+func DebugPrintTree(root *Node) {
+	debugPrintTreeR(root, 0)
+}
+
+func debugPrintTreeR(node *Node, indent int) {
+	for i := 0; i < indent; i++ {
+		fmt.Printf(" ")
+	}
+	fmt.Printf("Children: %d | Metadata: ", len(node.Children))
+
+	for _, md := range node.Metadata {
+		fmt.Printf("%d ", md)
+	}
+	fmt.Println()
+
+	for _, child := range node.Children {
+		debugPrintTreeR(child, indent+1)
+	}
+}

2018/internal/day08/tree.go

@@ -0,0 +1,30 @@
+package day08
+
+type Node struct {
+	Children []*Node
+	Metadata []int
+}
+
+func BuildTree(data []int) *Node {
+	root, _ := buildTreeR(data, 0)
+	return root
+}
+
+func buildTreeR(data []int, index int) (*Node, int) {
+	node := &Node{}
+	numChildren := data[index]
+	numMetadata := data[index+1]
+	index += 2
+
+	for i := 0; i < numChildren; i++ {
+		var child *Node
+		child, index = buildTreeR(data, index)
+		node.Children = append(node.Children, child)
+	}
+
+	for i := 0; i < numMetadata; i++ {
+		node.Metadata = append(node.Metadata, data[index+i])
+	}
+
+	return node, index + numMetadata
+}