Day 8

.gitignore

@@ -229,3 +229,5 @@ _Pvt_Extensions
 *.o
 *.hi
 *.out
+
+.vscode/

aoc-8/main.py

@@ -0,0 +1,63 @@
+# node struct
+class Node:
+    def __init__(self, num_children, num_metadata):
+        self.num_children = num_children
+        self.num_metadata = num_metadata
+        self.metadata = []
+        self.children = []
+
+    def full_children(self):
+        return len(self.children) == self.num_children
+    
+    def full_metadata(self):
+        return len(self.metadata) == self.num_metadata
+
+    def total_metadata(self):
+        return sum(self.metadata) + sum([ c.total_metadata() for c in self.children ])
+
+    def value(self):
+        if self.num_children == 0:
+            return sum(self.metadata)
+        else:
+            val = 0
+            for index in self.metadata:
+                if index <= len(self.children):
+                    val += self.children[index - 1].value()
+            
+            return val
+
+# build tree, list of ints -> root Node
+def build_tree(inputs):
+    root = None
+    node_stack = list()
+
+    i = 0
+
+    while root == None:
+        top_node = node_stack[-1] if node_stack else None
+
+        if top_node == None or not top_node.full_children():
+            num_children = inputs[i]
+            num_metadata = inputs[i + 1]
+
+            node_stack.append(Node(num_children, num_metadata))
+
+            i += 2
+        
+        else:
+            for j in range(top_node.num_metadata):
+                top_node.metadata.append(inputs[i])
+                i += 1
+
+            node = node_stack.pop()
+            
+            if node_stack:
+                node_stack[-1].children.append(node)
+            else:
+                root = node
+        
+    return root
+
+root = build_tree(list(map(lambda x: int(x), open("inputs.txt").read().split(' '))))
+print(f"[Part 1] Total metadata sum: { root.total_metadata() }")
+print(f"[Part 2] Root node value: { root.value() } ")