Data Structures

The data structure is a way of organizing and storing data in a computer so that it can be accessed and modified efficiently. Different types of data structures are suited to different kinds of applications, and some are highly specialized to specific tasks. Here are some examples of common data structures, along with descriptions and examples of their use:

Arrays

• The array is a simple data structure that stores a fixed-size sequential collection of elements of the same type. Each element can be accessed by its index number, and the size of the array is fixed when it is created. Arrays are often used to store large collections of data that need to be accessed quickly, such as lists of records or lookup tables.

here example, you might use an array to store a list of student names:

string[] studentNames = {"Alice", "Bob", "Charlie", "Dave", "Eve"};

Linked lists

A linked list is a data structure that stores a sequence of elements, each containing a link to its next element. Linked lists are used to store sequences of items where the order of the items is important, but the items do not need to be accessed by their indices.

For example, you might use a linked list to store a list of tasks that need to be completed in a particular order:

class Task {
  String description;
  Task next;
}

Task firstTask = new Task("Take out the trash", null);
Task secondTask = new Task("Do the dishes", firstTask);
Task thirdTask = new Task("Wash the car", secondTask);

Stack

A stack is a data structure that stores a collection of items in a last-in, first-out (LIFO) order. Stacks are often used to store temporary data, such as the state of a program or the results of intermediate calculations.

For example, you might use a stack to store a list of recently visited web pages in a browser:

Stack<string> history = new Stack<string>();
history.push("scripto-tech.com");
history.push("www.google.com");
history.push("www.stackoverflow.com");

Queue

A queue is a data structure that stores a collection of items in a first-in, first-out (FIFO) order. Queues are often used to store data that needs to be processed in a particular order, such as tasks to be executed by a computer or orders to be filled by a factory.

For example, you might use a queue to store a list of print jobs in a printer:

Queue<string> printQueue = new Queue<string>();
printQueue.enqueue("scripto-tech.1");
printQueue.enqueue("scripto-tech. 2");
printQueue.enqueue("scripto-tech.3");

Tree

Tree: A tree is a data structure that stores a collection of items in a hierarchical structure. Each item has a parent and zero or more children, and the top item (called the root) has no parent. Trees are often used to store data that has a natural hierarchy, such as the structure of a file system or the relationship between different pieces of data.

For example, you might use a tree to store a list of employees in an organization, with each employee having a manager and possibly several subordinates:

class TreeNode {
  String data;
  List<TreeNode> children;
  TreeNode(this.data, [this.children = const []]);
}

TreeNode root = TreeNode("Root");
TreeNode node1 = TreeNode("Node 1");
TreeNode node2 = TreeNode("Node 2");
TreeNode node3 = TreeNode("Node 3");
TreeNode node4 = TreeNode("Node 4");

root.children = [node1, node2, node3];
node2.children = [node4];

code creates a tree with the following structure:

        Root
       / | \
     1   2   3
           \
            4

Trees have many useful properties and can be used to solve a wide variety of problems. Some common operations that can be performed on trees include inserting and deleting nodes, searching for a specific node, and traversing the tree in various orders (such as in-order, pre-order, or post-order).