What are the main differences between a linked list and an array in data organization and access?

Main differences between a linked list and an array:

• Data organization:

  • An array is a contiguous block of memory where elements are stored sequentially.
  • A linked list consists of nodes, each containing data and a reference to the next (and/or previous) element.

• Access to elements:

  • In an array, access to an element by index occurs in constant time O(1).
  • In a linked list, accessing an element requires traversing links from the beginning, which takes O(n).

• Resizing:

  • A fixed-size array (in static languages), resizing requires allocating a new block and copying data.
  • A linked list dynamically expands, making it easy to insert and delete elements without shifting.

Example in Dart (Flutter):

// Array
List<int> array = [1, 2, 3];
print(array[1]); // Fast access

// Simplified linked list
class Node {
  int value;
  Node? next;
  Node(this.value);
}

Node head = Node(1);
head.next = Node(2);
head.next!.next = Node(3);

// Accessing the second element requires traversal
Node? current = head;
for (int i = 0; i < 1; i++) {
  current = current?.next;
}
print(current?.value);