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LinkedList

LinkedLists are sequences of nodes where each node contains data and connects to the next node. They are perfect for visualizing dynamic data structures and pointer-based algorithms.

Source Code

1linkedlist chain = {
2  nodes: [head, node1, node2, tail]
3  value: [10, 20, 30, 40]
4  color: ["green", "blue", "blue", "red"]
5  arrow: ["start", null, null, "end"]
6}
7

8page
9show chain

Rendered Diagram

Properties​

LinkedLists support the following properties:

PropertyTypeDescription
nodesid[]List of node identifiers
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 list
belowstring | text_objectLabel positioned below the list
leftstring | text_objectLabel positioned to the left
rightstring | text_objectLabel positioned to the right

Methods​

LinkedLists 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
  • insertNode(index | id, name, value?) - Insert node at specific position or after node ID with optional value
  • removeNode(name) - Remove specific node
  • 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

Value Methods​

  • addValue(value) - Add value to end of list
  • removeValue(value) - Remove first occurrence of value
  • removeAt(index) - Remove node at specific position

Multiple Element Methods​

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

Examples​

Basic LinkedList Example​

LinkedList with Pointers​

Source Code

1linkedlist pointers = {
2  nodes: [head, curr, next, end]
3  value: [1, 2, 3, null]
4  color: ["green", "blue", "yellow", "red"]
5  arrow: ["head", "current", "next", "null"]
6}
7

8page
9show pointers

Rendered Diagram

Dynamic LinkedList Operations​

Source Code

1linkedlist list = {
2  nodes: [n1, n2]
3  value: [10, 20]
4}
5

6page
7show list
8

9page
10list.addNode(n3, 30)
11list.setColor(2, "green")
12list.setArrow(2, "new")
13

14page
15// insert by index
16list.insertNode(1, n1_5, 15)
17list.setColors([null, "blue", null, "green"])
18list.setArrows([null, "inserted", null, null])
19

20page
21// insert after node ID
22list.insertNode(n1_5, n1_75, 17.5)
23list.setColors([null, "blue", "yellow", null, "green"])
24list.setArrows([null, "inserted", "after n1_5", null, null])
25

26page
27list.removeNode(n2)
28list.setValues([10, 15, 30])
29list.setColors([null, null, "green"])
30list.setArrows([null, null, null])

Rendered Diagram

LinkedList Traversal​

Source Code

1linkedlist traverse = {
2  nodes: [start, mid1, mid2, end]
3  value: ["first", "second", "third", "last"]
4  color: [null, null, null, null]
5}
6

7page
8show traverse
9

10page
11traverse.setColor(0, "blue")
12traverse.setArrow(0, "visiting")
13

14page
15traverse.setColor(0, "gray")
16traverse.setColor(1, "blue")
17traverse.setArrow(0, "visited")
18traverse.setArrow(1, "visiting")
19

20page
21traverse.setColor(1, "gray")
22traverse.setColor(2, "blue")
23traverse.setArrow(1, "visited")
24traverse.setArrow(2, "visiting")

Rendered Diagram

Sorted LinkedList Insertion​

Source Code

1linkedlist sorted = {
2  nodes: [n10, n30, n50]
3  value: [10, 30, 50]
4  above: "Sorted LinkedList"
5  below: "Inserting 25"
6}
7

8page
9show sorted
10

11page
12// insert after n10 node
13sorted.insertNode(n10, n25, 25)
14sorted.setColor(1, "red")
15sorted.setArrow(1, "inserted")

Rendered Diagram

Use Cases​

LinkedLists are ideal for:

  • Dynamic data structures - Variable-length lists, memory allocation
  • Insertion/deletion operations - Efficient mid-list modifications
  • Pointer manipulation - Understanding references and links
  • Queue implementation - FIFO using linked nodes
  • Stack implementation - Alternative to array-based stacks
  • Graph representations - Adjacency lists
  • Memory management - Free lists, garbage collection
  • Algorithm visualization - Merging, splitting, reversing lists
  • Methods Reference - Complete list of linkedlist methods
  • Array - Alternative linear structure
  • Stack - LIFO structure that can use linked nodes
  • Graph - Uses similar node-based concepts