CS102-1 Prelim

if the front and rear are adjacent with each other.

How do you know if a circular queue is full??

Efficiency of a program depends upon the choice of data structure. Data structures are reusable. Data structure is specified by the ADT which provides a level.

Importance of Implementing Data Structures

priority number

In Priority Queue deletions are based on?

First In First Out

In Priority Queue, In the case of deleting element with the same priority what is done to break the tie?

priority number

In Priority Queue, a number is associated with every element of the queue?

tail

Unlike Singly Linked List, it has a ________ pointer that points at the end of the list.

Input-restricted deque, Output-restricted queue

Variations of Double Ended Queue

Push(element) Pop() Top()

What are the 3 operations used in Stack Data Structure?

principle of First In First Out(FIFO)

What does QUEUE DATA STRUCTURE follows?

data found or data is not in the list

What is the result of retrieving data in a singly linked list?

Scheduling and Processes

What job does Priority Queue used in Operating System?

waiting lists, buffers, and handling job scheduling.

What jobs can Priority Queue be used?

Last-In First -Out (LIFO) principle

What procedure does Stack follows?

If you know the maximum number of data that will be stored.

When does a circular queue can be advantageous?

The applications

Where does priority number comes from?

end of the list

Where does the new element is inserted in Queue Data Structure?

complex implementation of operations on linked list structure.

Disadvantage of Circular Linked List

1. Scan the postfix expression from left to right one token at a time. 2. If the scanned token is an operand, push it onto the stack. 3. If the scanned token is an operator, pop two operands from the stack. Perform the evaluation with the two operands using the scanned operator. Push the result to the stack. 4. Repeat steps 1 to 4 until all tokens are scanned. 5. Once all tokens are scanned, pop the stack to return the evaluation of the expression.

Evaluating Expression Algorithm

Array, Linked List, Stack, Queue

Examples of Linear Data Structure

Trees and Graphs

Examples of Non-Linear Data Structure

data, previous, and next pointer.

For a doubly linked list, each node has three fields

data and next pointer

For a singly linked list, each node has two fields

Postfix or reverse Polish notation

The operator is placed after the operands. For example, ab+.

Prefix or Polish notation

The operator is placed before the operands. For example, +ab.

Infix notation

The operator is placed in between the operands. For example, a +b.

edges

what do you call the link that connect nodes in a graph?

data organization management efficient access and modification functions or operations that can be applied to the data

what is a data structure?

NULL

what is set unto the pointer if it is the last node in a singly linked list?

Doubly Linked List

A data structure that consists of a sequence of elements each of which contains a reference to the previous and next elements in the list.

Singly Linked List

A singly linked list is a data structure that consists of a sequence of elements each of which contains a reference to the next element.

Double Ended Queue

A type of queue in which insertions and deletions can be made at both ends of the queue

1. provides easy manipulation of the pointers and the searching becomes twice as efficient. 2.Efficient utilization of memory allocation

Advantages of Circular Linked List

Recursive Call Some functionalities in browser and editor. Parsing Expression conversion

Applications of Stack

Stack Data Structure

Are linear data structures in which elements can be inserted and deleted at only one end of the list

QUEUE DATA STRUCTURE

Are linear data structures in which elements can be inserted in one end called rear and deleted from the other end called front.

Infix, Prefix or Polish, and Postfix or reverse Polish notation

Arithmetic Expression can be expressed in three notation

1. Scan the infix string from left to right one character at a time. 2. If the scanned character is an operand, append it to the postfix string. 3. If the scanned character is an operator and the stack is empty, push the operator to the stack. 4.If scanned character has higher precedence over operator on top of stack, push the operator to the stack. 5. If scanned character has lower or same precedence over operator on top of stack, pop the stack and append to postfix string. Repeat step 5b while the condition is true. 6.Repeat steps 1 to 5 until all the characters are scanned. 7.After all characters are scanned, append all remaining operators to the postfix string one at a time using pop operator. 8. Lastly, once the stack is empty, return the postfix string.

Infix to Postfix Conversion Algorithm

Output-restricted deque

Insertion can be made at both ends of the queue and deletion can be made at only one end of the queue.

Input-restricted deque

Insertions can be done only at one end of the queue and deletions can be made at both ends of the queue.

First we need to create a new node. Set the data value 80 in its data field and null in the next pointer field. Since we should not be moving the head pointer to eliminate changing the start of the list. We need to use another pointer ( current). This pointer will be used to move from one node to another. We need to set the current pointer to point initially with our first node in the list. We need to traverse until the end of the list. We will know if we are the end of the list if the pointer field pointed to by the current pointer is null. We simply set the pointer field pointed to by current to point to the new node

Operations on Singly Linked List: Inserting data on the list

1. Remove the node from the list without breaking the links created by the next pointers. 2.Deleting from the memory

Operations on Singly Linked List: Removing data on the list

We have to traverse from the start of the list using another pointer(current) and compare the data field pointed by the current pointer to the value being searched.

Operations on Singly Linked List: Retrieving data on the list

1. Check, if the next pointer field of the node is null; 2. If the next pointer field is null, then you have reached the end of the list. Otherwise, you may perform some actions with the current node. 3. Move the current pointer to the next node and do step 1.

Operations on Singly Linked List: Traversing the entire list

Once you delete the data pointed by front, you can no longer use that storage.

Problem with Simple Queue

Double Ended Queue

Provides a simple way of implementing the idea of queue

array and linked lists

Queue Data Structure can be represented as?

DEREFERENCE OPERATOR (*)

Read as "value pointed to by"

REFERENCE OPERATOR (&)

Returns the memory address of a variable.

Restricted

Specifically identifies where insertion and deletion will be performed.

Arrays and Linked Lists

Stacks can be represented in?

leaf node

The bottommost nodes in the hierarchy of a tree

Dequeue

The deletion of elements from a queue

Pop

The deletion of elements from a stack

Front

The end which the elements are deleted. (queue)

Rear

The end which the elements are inserted. (queue)

Circular Queue

The first subscript comes right after the last subscript.

Enqueue

The insertion of elements into a queue.

Push

The insertion of elements into a stack.

root node

The topmost nodes in the hierarchy of a tree

Higher priority

Which will be the first deleted a higher priority element or a lower priority element?

Array

a collection of similar data type of data items and each data item is called an element of the array

Linked List

a linear data structure which is used to maintain a list in the memory. It can be seen as the collection of nodes stored at non-contiguous memory locations. Each node of the list contains a pointer to its adjacent node.

Queue

a linear list in which elements can be inserted only at one end called rear and deleted only at the other end called front.

Stack

a linear list which insertion and deletions are allowed only at one end, called top.

circular doubly linked list

a linked list where the last element in the list is connected to the first node while the first element is connected to the last node.

circular singly linked list

a linked list where the last element in the list is connected to the first node.

front

a part of queue where elements can be deleted only at one end

rear

a part of queue where elements can be inserted only at one end

top

a part of stack where insertion and deletions are allowed only

Unordered list

a random listing of elements and operations can be performed anywhere on the list. Although, most of the time insertion happens at the end of the list.

Linear List

a type of list in which each element has a unique successor and predecessor.

Pointer

a variable that stores the memory address of another variable.

FIFO (First In First Out)

allows insertion only at the end of the list called rear, while deletion is only allowed at the beginning of the list called front.

Arithmetic Expression

an expression which involves arithmetic operators, constants and variables and ultimately evaluates to a numeric value.

Trees

are multilevel data structure with a hierarchical relationship among its elements known as nodes

Primitive Data Structure

are structures that are embedded in a particular language

Graphs

can be defined as the pictorial representation of the set of elements (represented by vertices) connected by the links known as edges

Non-Primitive Data Structures

complex data structure that is embedded in a programming language.

Pointer

contains the address of the next node in the list

Non-Linear Data Structures

data elements are not arranged in sequential structure and can have multiple successors ad predecessors.

Linear Data Structures

data elements are stored in a non-hierarchical way where each elements has successor and predecessor except the first and last element.

Ordered list

data will be inserted or remove using a key.

Operating system

decide the particular memory locations on runtime

Node

elements in a linked list.

Integer, Character, Float and Double.

examples of Primitive Data Structure

Top

holds the address of the first node of the linked list in a stack

Push(element)

insert data element at the end or top of the list.

Enqueue(element)

insert data element at the start end or rear of the list.

LIFO(Last In First Out)

only allows insertion and deletion of elements at the end of the list called top.

Pop()

remove data element at the end or top of the list.

Dequeue()

remove data element at the start or front of the list.

Top()

retrieve the data element at the end or top of the list without removing it from the stack. This will just give the data pointed by the top variable.

Rear()

retrieve the data element at the ends of the list without removing it from the queue.

Front()

retrieve the data element at the start of the list without removing it from the queue.

Top of the Stack

the end at which the elements are inserted and removed. (stack)

General list

type of list structure where we are free to add and remove data elements anywhere on the list.