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Tree

Trees are hierarchical data structures with parent-child relationships. They are perfect for visualizing tree algorithms, organizational structures, and hierarchical data.

Source Code

1tree family = {
2  nodes: [grandpa, dad, mom, child1, child2]
3  children: [grandpa-dad, grandpa-mom, dad-child1, dad-child2]
4  value: ["John", "Mike", "Sarah", "Emma", "Alex"]
5  color: ["gold", "blue", "pink", "lightblue", "lightgreen"]
6}
7

8page
9show family

Rendered Diagram

Properties​

Trees support the following properties:

PropertyTypeDescription
nodesid[]List of node identifiers
childrenchild[]Parent-child relationships (e.g., parent-child)
value(number | string | null)[]Values for each node
color(color | null)[]Colors for each node
arrow(number | string | null)[]Arrows or labels for each node
abovestring | text_object (see special features)Label positioned above the tree
belowstring | text_objectLabel positioned below the tree
leftstring | text_objectLabel positioned to the left
rightstring | text_objectLabel positioned to the right

Methods​

Trees support these methods for manipulation:

Text Positioning Methods​

  • setText(text, position) - Set or remove text at specific positions ("above", "below", "left", "right")

Node Methods​

  • addNode(name, value?) - Add new node with optional value
  • removeNode(name) - Remove node and its subtree
  • setValue(index | id, value) - Set value for node at index or node id
  • setColor(index | id, color) - Set color for node at index or node id
  • setArrow(index | id, arrow) - Set arrow for node at index or node id

Tree Structure Methods​

  • addChild(parent-child, value?) - Add child to parent with optional value
  • setChild(parent-child) - Change parent-child relationship
  • removeSubtree(node) - Remove node and entire subtree

Multiple Element Methods​

  • setValues([...]) - Set multiple node values
  • setColors([...]) - Set multiple node colors
  • setArrows([...]) - Set multiple node arrows

Examples​

Basic Tree Example​

Binary Search Tree​

Source Code

1tree bst = {
2  nodes: [root, l, r, ll, lr]
3  children: [root-l, root-r, l-ll, l-lr]
4  value: [50, 30, 70, 20, 40]
5  color: [null, null, null, null, null]
6}
7

8page
9show bst

Rendered Diagram

Dynamic Tree Operations​

Source Code

1tree org = {
2  nodes: [CEO, CTO]
3  children: [CEO-CTO]
4  value: ["Alice", "Bob"]
5}
6

7page
8show org
9

10page
11org.addChild(CEO-CFO, "Carol")
12org.setColor(CFO, "lightgreen")
13

14page
15org.addChild(CTO-DevLead, "Dave")
16org.setColor(DevLead, "lightblue")
17

18page
19org.addChild(DevLead-Engineer, "Eve")
20org.setColor(Engineer, "yellow")

Rendered Diagram

Tree Traversal Visualization​

Source Code

1tree traverse = {
2  nodes: [A, B, C, D, E]
3  children: [A-B, A-C, B-D, B-E]
4  value: [1, 2, 3, 4, 5]
5}
6

7page
8show traverse
9

10page
11traverse.setColor(A, "blue")
12traverse.setArrow(A, "visiting")
13

14page
15traverse.setColor(B, "blue")
16traverse.setArrow(B, "visiting")
17traverse.setColor(A, "gray")
18traverse.setArrow(A, "visited")
19

20page
21traverse.setColor(D, "blue")
22traverse.setArrow(D, "visiting")
23traverse.setColor(B, "gray")
24traverse.setArrow(B, "visited")

Rendered Diagram

Organizational Chart​

Source Code

1tree company = {
2  nodes: [president, marketing, engineering, sales]
3  children: [president-marketing, president-engineering, president-sales]
4  value: ["Jane Smith", "Marketing Dept", "Engineering Dept", "Sales Dept"]
5  color: ["gold", "lightcoral", "lightblue", "lightgreen"]
6  above: "Company Structure"
7}
8

9page
10show company

Rendered Diagram

Use Cases​

Trees are ideal for:

  • Tree algorithms - Tree traversal (pre/in/post-order), tree search
  • Binary search trees - Insertion, deletion, search operations
  • Decision trees - Decision making processes, game trees
  • Parse trees - Syntax trees, expression evaluation
  • File systems - Directory hierarchies, folder structures
  • Organizational charts - Company hierarchy, family trees
  • Heap operations - Priority queues, heap sort visualization
  • Trie structures - String matching, autocomplete