Introduction to Data Structures in C

As applications are becoming data-rich and complex, you can find 3 typical issues that apps deal with at present. These are Data Search, Processor speed, and Multiple requests. To resolve these issues, data structures in C get to the rescue. Information could be structured in data structures in C programming in such a manner that all of the items might not be made to be searched, and the essential info may be looked at almost instantly.

The data structures in C programming name signify by themselves arranging the data in memory. You will find numerous methods for arranging the data in the memory as we’ve previously seen one of the data structures in C tutorial, i.e., the array present in the C programming language. The array is a set of memory elements in which data is kept sequentially, i.e., one following another. Basically, we can state that the array stores the elements in a consistent way. This particular organization of data is done with the assistance of an array of data structures in C. Additionally, there are various other methods to manage the data in memory.

Nearly every business application employs different forms of data structures in C in one or perhaps another way. The following data structures in C tutorial will give you an excellent knowledge of the Data Structures in C tutorial required to fully grasp the complexity of enterprise-level applications and the need for algorithms, and data structures in C. Let us look at the various categories of data structures in C programming. You can also check out our blogs Linear and Non Linear Data Structure, Graph in Data Structure and Recursion in Data Structure.

What is C Programming Language?

C is a procedural and a general-purpose computer programming language. It supports structured programming, and lexical variable scope, in addition to recursion, with a static style system. By layout, C offers constructs that map effectively to traditional machine operating instructions. It’s identified long-term usage in software applications earlier coded in assembly language. 

Such software applications consist of operating various application software and systems for computer architectures that cover anything from supercomputers to PLCs plus embedded systems. Lots of later languages have taken syntax or features indirectly or directly from the C programming language. For instance syntax of Java, JavaScript, PHP, and several other languages. They are primarily based on the C language. C++ is practically a superset of C language (Few programs might compile in C, however, not within C++).

Also Read : How to Remove Duplicates from Array in Java

Structure of a C program

Following the above conversation, we can formally evaluate the structure of a C program. By structure, it’s intended that just about any program could be created in that structure only. Writing a C program in another structure will hence contribute to a Compilation Blunder.

Header Files Inclusion: The primary part is the addition of your Header files within a C program. The header is the file with the extension,h. It contains the C function declarations along with macro definitions for being shared between a number of source files. Important C Header files:

• stddef.h – Defines various valuable types and macros.
• stdint.h – Defines particular width integer types.
• stdio.h – Defines key input and output functions
• stdlib.h – Defines numeric transformation functions, pseudo-random network generator, and the memory allocation
• string.h – Defines string managing functions
• math.h – Defines typical mathematical functions

Main Method Declaration: The other element of a C program is declaring the main() function. The syntax to declare is:

int main()

{}

1. Variable Declaration: Another element of any C program is the variable declaration. It is the term for the variables that are to be utilized in the function. You should be aware that in the C program, certainly no variable could be used without being declared. Furthermore, in a C program, the variables are to be declared prior to any operation in the function.

Example:

int main()

{

int a;

Body: The body of a function within the C program, represents the operations that are carried out within the functions. It could be just about anything as manipulations, printing, sorting, searching, etc.

Example: 

int main()

{

    int a;

    printf(“%d”, a);

Return Statement: The ultimate section of any C program is the return statement. The return statement is the term for the returning of the values by a function. This return statement in addition to the return value relies on the return type of the function. For instance, in case the return type is void, consequently, there is going to be no return statement. In any other case, there is going to be a return statement along with the return value of the sort of the specified return type.

Example:

int main()

{

int a;

printf(“%d”, a);

return 0;

}

• Writing the first program: Following is the simplest program in C

#include

int main(void)

{

printf(“DataTrained“);

return 0;

}

Executing the above program: To execute the above-mentioned program, we require a compiler to compile and run our programs. There are certain offline and online compilers to do this task.

What are Data Structures in C?

The data structures in C is a set of data values that permits saving, arranging, and also finding information effectively. Algorithms and Data Structures in C programming assist programmers to take care of the details effectively. They’re a crucial aspect of countless computer algorithms. With data structures in C, critical operations are usually carried out with much fewer resources. An informed choice of data structures in C can enhance the effectiveness of a computer program or even software.

Why Learn Algorithms and Data Structures in C?

As applications are getting data-rich and complex, you’ll notice 3 common issues that apps face these days.

1. Data Search: Take into account an inventory of one million(106) items of a shop. In the event the application program is searching for something, it has to look at an item in one million(106) items each time thus slowing down the search. As data increases, the search is going to become slower.
2. Processor
   speed: Processor speed despite the fact that being quite high, falls restricted if the information expands to a billion records.
3. Multiple requests: As a huge number of users can look at data concurrently for a web server, possibly even the quickest server fails while seeking the details.

To resolve the above-mentioned issues, algorithms and data structures in C get to the rescue. Information could be sorted out in a data structure in a way that all of the items might not be made to be searched, and also the necessary info will be explored very quickly.

Applications of Data Structures in C

An algorithm is a step-by-step process, which describes a set of guidelines for being carried out in a specific order to receive the ideal output. Algorithms are typically developed independent of underlying languages, i.e. an algorithm could be carried out in over one programming language. From the data structure perspective, below are a number of essential types of algorithms:

1. Search: Algorithm to browse things in data structures in C.
2. Sort: Algorithm to sort objects in a specific order.
3. Insert: Algorithm to place objects in data structures in C.
4. Update: Algorithm to upgrade an existing thing in data structures in C.
5. Delete: Algorithm to delete a current object from data structures in C.

This particular computer complication could be sorted out by applying Data Structures in C

1. Fibonacci number series
2. Knapsack problem
3. Tower of Hanoi
4. All pair least path by Floyd-Warshall
5. Shortest path by Dijkstra
6. Project scheduling

Types of Data Structures in C

Information could be set up in a number of different ways like the mathematical or logical model for a specific enterprise of information is called data structures in C. The selection of a particular

the data model is dependent on the 2 aspects –

1. For starters, it should be loaded adequate in structure to represent the actual associations of the data with the real-world object.
2. Next, the development needs to be straightforward enough to ensure that any individual could efficiently process the data every time it’s necessary.

Two types of data structures in C:

1. Primitive data structures in C
2. Non-primitive data structures in C

• Primitive Data Structures in C: The primitive data structures in C are the primitive data types. The int, double, float, char, along with pointer are the primitive data structures in C that could store just one value.
• Non-primitive Data Structures in C: The non-primitive data structures in C are split into 2 types:
  1. Linear data structures in C
  2. Non-linear data structures in C

Linear Data Structures in C:

Linear Data structures in C are believed to be linear in the event that their elements combine to develop any particular order. You will find essentially 2 methods that represent these kinds of linear structures in memory.

1. The main strategy is providing the linear associations among each of the elements represented by methods of a linear memory location. These linear structures are referred to as arrays.
2. The next strategy is providing the linear relationship with all the elements represented by making use of the approach of links or pointers. These kinds of linear structures are named linked lists.

The typical illustrations of the linear data structures in C are:

1. Arrays
2. Queues
3. Stacks
4. Linked lists

Non-linear data structures in C:

This structure is primarily employed for representing data that consists of a hierarchical connection involving a variety of elements. 

Examples of Non-Linear Data Structures in C:

1. Graphs
2. family of trees and
3. table of contents

Types of Data structures in C could likewise be categorized as:

1. Static data structure: These are kinds of data structures in C in which the size is assigned at the compile time. Consequently, the optimum size is set.
2. Dynamic data structure: It’s a sort of data structures in C in which the size is allotted at the run time. As a result, the max size is adaptable.

Data Structures in C

The following is a list of Data Structures in C:

1. Array
2. Linked List
3. Stack
4. Queue
5. Binary Tree and Binary Search Tree
6. Heap
7. Hashing
8. Graph

Array in C

An array is a container that could store a set amount of items and these items need to be of the identical sort. The majority of the data structures in C make use of arrays to carry out their algorithms. Below are the essential terms to grasp the idea of Array.

1. Element: Every item saved in an array is referred to as an element.
2. Index: Every spot of an element in an array features a numerical index, that is utilized to determine the element.

Array Representation(Storage structure): Arrays could be declared in a variety of ways in different languages. For illustration, let us take the C array declaration.

As per the above-mentioned illustration, the following are t
he essential factors to be considered.

Index starts with 0.

• Array length is 10 this means it can keep 10 elements.
• Every element could be accessed via its index. Like we could get an element at index 6 as 9.

Fundamental Operations: Below are the basic operations supported by an array of data structures in C.

1. Traverse: print every one of the array elements one after the other.
2. Insertion: This adds the element at a specified index.
3. Deletion: Deletes an element at the specified index.
4. Search: Searches an element utilizing the specified index or by the value.
5. Update: This updates the element at a specified index.

In C, when an array is initialized with size, in that case, it assigns defaults values to its elements within the succeeding order.

Data Type	Default Value
bool	false
char	0
int	0
float	0.0
double	0.0f
void	–
wchar_t	0

Insertion Operation:

Insert operation is inserting one or even more data elements into an array. Depending on the necessity, a fresh element could be incorporated at the start, end, or perhaps any given index of an array. In this case, we see a sensible application of insertion operation, in which we put data at the end of the array.

Algorithm:

Let LA be a Linear Array (unordered) with N elements and K is a positive integer in a way that K <=N. Below is the algorithm wherein the Item is put into the Kth position of LA.

1. Start
2. Set J = N
3. Set N = N+1
4. Repeat steps 5 and 6 while J >= K
5. Set LA[J+1] = LA[J]
6. Set J = J-1
7. Set LA[K] = ITEM
8. Stop

Example:

Following is execution of the above algorithm:

#include

main() {

int LA[] = {1,3,5,7,8};

int item = 10, k = 3, n = 5;

int i = 0, j = n;

printf(“The original array elements are :n”);

for(i = 0; i<n; i++) {

printf(“LA[%d] = %d n”, i, LA[i]);

}

n = n + 1;

while( j >= k) {

LA[j+1] = LA[j];

j = j – 1;

}

LA[k] = item;

printf(“The array elements after insertion :n”);

for(i = 0; i<n; i++) {

printf(“LA[%d] = %d n”, i, LA[i]);

}

}

Once we compile and then carry out the above-mentioned program, it generates the subsequent result.

Output:

The original array elements are:

LA[0] = 1

LA[1] = 3

LA[2] = 5

LA[3] = 7

LA[4] = 8

The array elements after insertion:

LA[0] = 1

LA[1] = 3

LA[2] = 5

LA[3] = 10

LA[4] = 7

LA[5] = 8

Deletion Operation:

Deletion is the term for removing a current element through the array and re-organizing almost all elements of an array.

Algorithm:

Think about LA as a linear array with N elements. Then K is a positive integer in a way that K <=N. Below is the algorithm to delete an element available at the Kth position of LA.

1. Start
2. Set J = K
3. Repeat steps 4 and 5 while J < N
4. Set LA[J] = LA[J + 1]
5. Set J = J+1
6. Set N = N-1
7. Stop

Following is the execution of this algorithm:

#include

void main() {

int LA[] = {1,3,5,7,8};

int k = 3, n = 5;

int i, j;

printf(“The original array elements are :n”);

for(i = 0; i<n; i++) {

printf(“LA[%d] = %d n”, i, LA[i]);

}

j = k;

while( j < n) {

LA[j-1] = LA[j];

j = j + 1;

}

n = n -1;

printf(“The array elements after deletion :n”);

for(i = 0; i<n; i++) {

printf(“LA[%d] = %d n”, i, LA[i]);

}

}

Once we compile and then carry out the above-mentioned program, it generates the subsequent result.

Output:

The original array elements are :

LA[0] = 1

LA[1] = 3

LA[2] = 5

LA[3] = 7

LA[4] = 8

The array elements after deletion :

LA[0] = 1

LA[1] = 3

LA[2] = 7

LA[3] = 8

Search Operation:

You can conduct a search for an array element depending on its value or perhaps its index.

Algorithm:

Consider LA is a linear array with N elements. Then K is a positive integer so that K <=N. Below is the algorithm to identify an element with a value of an Item using sequential search.

1. Start
2. Set J = 0
3. Repeat steps 4 and 5 while J < N
4. IF LA[J] is equal ITEM THEN GOTO STEP 6
5. Set J = J +1
6. PRINT J, ITEM
7. Stop

Following is the execution of this algorithm:

#include

void main() {

int LA[] = {1,3,5,7,8};

int item = 5, n = 5;

int i = 0, j = 0;

printf(“The original array elements are :n”);

for(i = 0; i<n; i++) {

printf(“LA[%d] = %d n”, i, LA[i]);

}

while( j < n){

if( LA[j] == item ) {

break;

}

j = j + 1;

}

printf(“Found element %d at position %dn”, item, j+1);

}

Once we compile and then carry out the above-mentioned program, it generates the subsequent result.

Output:

The original array elements are:

LA[0] = 1

LA[1] = 3

LA[2] = 5

LA[3] = 7

LA[4] = 8

Found element 5 at position 3

Update Operation:

The update operation is the term for updating a current element from your array at a specified index.

Algorithm:

Think of LA as a linear array with N elements. Then K as a positive integer in a way that K <=N. Below is the algorithm to update an element available at the Kth position of LA.

1. Start
2. Set LA[K-1] = ITEM
3. Stop

Following is the execution of this algorithm:

#include

void main() {

int LA[] = {1,3,5,7,8};

int k = 3, n = 5, item = 10;

int i, j;

printf(“The original array elements are :n”);

for(i = 0; i<n; i++) {

printf(“LA[%d] = %d n”, i, LA[i]);

}

LA[k-1] = item;

printf(“The array elements after updation :n”);

for(i = 0; i<n; i++) {

printf(“LA[%d] = %d n”, i, LA[i]);

}

}

Once we compile and then carry out the above-mentioned program, it generates the subsequent result.

Output:

The original array elements are :

LA[0] = 1

LA[1] = 3

LA[2] = 5

LA
[3] = 7

LA[4] = 8

The array elements after updation :

LA[0] = 1

LA[1] = 3

LA[2] = 10

LA[3] = 7

LA[4] = 8

Linked list in C

A linked list is a sequence of data structures in C that are linked collectively by means of links. A linked list is a sequence of links that consist of items. Every link possesses a connection to another link. The Linked lists are the 2nd most-used data structures in computer science following the array.

Following are the essential terms to grasp the principle of Linked List.

1. Link: Every link associated with a linked list can save information referred to as an element.
2. Next: Every link associated with a linked list has a link to the subsequent link named Next.
3. LinkedList: A Linked List comprises the connection link to the initial link called First.

Linked List Representation:

A linked list could be visualized for a chain of nodes, in which every node points to the subsequent node.

According to the above-mentioned illustration, the following are the essential factors to be considered.

1. Linked List has a link element called first.
2. Each link carries a data field(s) plus a link field called next.
3. Each link is linked with its next link making use of its next link.
4. The last link has a link as null to mark the conclusion of the list.

Types of Linked List

The following are the different types of linked lists.

1. Simple Linked List: Item navigation is forward mainly.
2. Doubly Linked List: Items could be navigated backward and forward.
3. Circular Linked List: The very last item consists of a link of the initial element as next and the first element has a link to the last element as previous.

Stack in C

A stack is an Abstract Data Type (ADT), generally used in numerous programming languages. It is known as a stack since it acts as a real-world stack, for instance – a deck of cards or a stack of plates, etcetera. A real-world stack makes it possible for operations at one end merely. For instance, we can put plates or cards from the top of the stack only. Likewise, Stack ADT permits all data operations at one particular end primarily. At any time, we can simply access the topmost element of a stack.

This specific aspect causes it to be LIFO data structures in computer science. LIFO stands for Last-in-first-out. Here, the element which is positioned (inserted or added) last, is used first. In stack terminology, insertion operation is referred to as Push operation, and removal operation is known as POP operation.

Stack Representation:

The following diagram depicts a stack and also its operations.

A stack could be carried out by methods of Array, Pointer, Structure, and also Linked List. The stack can

possibly be a fixed size 1 or maybe it could have a sense of dynamic resizing. At this point, we’re heading to carry out a stack utilizing arrays, making it a fixed-size stack implementation.

Fundamental Operations:

Stack operations could include initializing the stack, utilizing it, and after that de-initializing it. Apart from

this fundamental stuff, a stack is applied for the next 2 principal operations:

1. push( ): Pushing (storing) an element on the stack.
2. pop( ): Removing (accessing) an element from the stack.

Then data is Pushed onto the stack. To work with a stack proficiently, we have to examine the state of the stack too. For the very same purpose, the subsequent function is put in to stacks:

1. peek( ): Discover the top data element of the stack, without the need of getting rid of it.
2. isFull( ): Examine if stack is full.
3. isEmpty( ): Investigate if stack is empty.

At all times, we sustain a pointer to the last PUSHed data on the stack. Since this pointer always

signifies the top of the stack, hence called the top. The top pointer offers the top value of the

stack devoid of really getting rid of it.

Queue in C

The queues are abstract data structures in C, rather comparable to Stacks. Compared with stacks, a queue is open at both ends. One end is constantly utilized to place data (enqueue) and also the other is needed to

eliminate data (dequeue). To begin with, it will be accessed first. A real-world example of a queue could be a single-lane one-way path, where the car enters initially, and exits in the beginning. More real-world instances are seen as queues on the ticket windows in addition to bus stops.

 

Queue Representation:

As we now realize this for the queue, we access each end for various reasons. The diagram beneath explained queue representation as data structures in computer science:

Binary Tree and Binary Search Tree

Binary Tree: A binary tree comprises a limited set of nodes that are either empty or maybe incorporates one specially allocated node is referred to as the root of the binary tree, and also the elements of 2 disjoint binary trees known as the left subtree and right subtree of this root. Take note that the definition above is recursive: we’ve determined a binary tree in terms of binary trees. This is suitable since recursion is an inbuilt characteristic of the tree structures.

Binary Search Tree: A binary search tree is data structures in C that rapidly enables us to manage a sorted list of numbers. It’s known as a binary tree due to the fact every tree node possesses the highest of 2 children. It’s referred to as a search tree since it could be employed to look for the existence of a number in O(log(n)) time.

Heap in C

Heap data structures in C are a complete binary tree that fulfills the heap property. Wherein any of the specified nodes are:

1. Constantly more significant compared to its child node/s together with the key of the root node is the largest among any other nodes. This particular property is additionally known as max heap property.
2. Constantly lesser compared to the child node/s together with the key of the root node is the smallest among any other nodes. This particular property can also be referred to as min-heap property.

This type of data structures in computer science is also referred to as a binary heap.

Hashing in C

Hashing is a technique or procedure of mapping keys, and values to the hash table by making use of a hash function. It’s used for a quicker approac
h to elements. The effectiveness of mapping is dependent on the performance of the hash function employed.

The issue at hand is speeding up the search process. Think of the challenge of looking at an array for a certain value. In the event the array isn’t sorted, the search may call for examining each & every element of the array. In case the array is sorted, we can make use of the binary search, and consequently minimize the worst-case runtime complexity to O(log n). 

We might search a lot quicker in case we know beforehand the index at which that value is placed in the array. Assume we do have that miraculous function that could inform us of the index for a certain value. Due to this miraculous function, our search is minimized to only 1 probe, providing us a continuous runtime O(1). This type of function is referred to as a hash function. A hash function is a feature that when provided a key, yields an address in the table.

A hash function example is a book call number. Every book in the library has a distinctive call number. A call number is like an address: it informs us where the book is placed in the library. A lot of academic libraries in the world make use of the Library of Congress Classification for call numbers. This process employs a blend of numbers and letters to sort out components by subjects.

Graph in C

A graph is composed of:

1. A set, V, of vertices (nodes)
2. A collection, E, of pairs of vertices from V referred to as edges (arcs)

Edges, also identified as arcs, are represented by (u, v) plus are either:

1. Directed when the pairs are ordered (u, v)
2. u the origin
3. v the destination
4. Undirected if the pairs happen to be unordered

A graph is a pictorial representation of a set of objects in which certain pairs of items are linked by links. The interconnected objects are shown by points called vertices, along with the links that attach to the vertices are known as edges. Formally, a graph is a set of sets (V, E), in which V is the set of vertices plus E is the set of edges, joining the pairs of vertices. Check out the given graph:

Operations on Data Structures in C

The primary or the typical functions that could be carried out on the data structures in C are:

1. Searching: We could search for almost any element in data structures in C.
2. Sorting: We could sort the elements of data structures in C in both a descending or ascending order.
3. Insertion: We could also put the new element in data structures in C.
4. Updated: We could additionally update the element, i.e., we can substitute the element with a different element.
5. Deletion: We can furthermore execute the delete operation to get rid of the element from the data structures in C.

Advantages of Data Structures in C

The advantages of a data structure in C are stated below:

1. Efficiency: If the preference of a data structure for executing a certain ADT is correct, it will make the program really effective when it comes to space and time.
2. Reusability: The data structure offers reusability implies that a number of client programs can make use of the data structure.
3. Abstraction: The data structure specified by an ADT additionally offers the level of abstraction. The client can’t view the inner functioning of the data structure, therefore it doesn’t have to be concerned about the execution part. The client is only able to observe the interface.

Conclusion 

Excellent knowledge of data structures in C can assist you to boost the overall performance of a computer program and also efficiently carry out tasks associated with data processing or computations. You would also be able to improve your problem-solving skills by mastering data structures in C. Mastering data structures can assist you to enhance your career and securing high-paying careers in the programming arena.

Frequently Asked Question’s

1. What is data structures in C and C++?

C/C++ arrays permit you to identify variables that incorporate various data objects of the identical type, however, the structure is another user-defined data type that enables you to merge data items of various types.

Structures are implemented to signify a record, imagine you wish to monitor your books inside a library. You may want to monitor the subsequent characteristics of every book:

1. Title
2. Author
3. Subject
4. Book ID

2. What is basic data type in C?

Here are the examples of a few extremely common data types employed in C:

1. char: Probably the most fundamental data type in C. It saves a single character and calls for a sole byte of memory in nearly all compilers.
2. int: As the term indicates, an int variable is utilized to an integer.
3. float: It’s utilized to hold decimal numbers (figures with floating-point value) with single preciseness.

double: It’s utilized to save decimal numbers (figures with floating-point value) with double preciseness.

3. What is tree in DAA?

The tree is hierarchical data structures in C identified as a set of nodes. Nodes signify value and the nodes are linked by edges. A tree has the below-mentioned properties:

1. The tree has one node known as a root. The tree emanates from this, and therefore it doesn’t have any parents.
2. Each node has one parent mainly but may have several children.
3. Each node is linked to its children through the edge.

4. What is heap and its types?

A Heap is a unique Tree-based data structure. In this, the tree is a complete binary tree. In general, Heaps are generally of 2 types:

1. Max Heap: In a Max Heap the key existing at the root node should be the biggest amongst the keys existing at all of its children. The identical property should be recursively correct for just about all sub-trees in this Binary Tree.

Min Heap: In a Min Heap the key existing at the root node should be least amongst the keys contained in all of its children. The identical property should be recursively correct for just about all sub-trees in this Binary Tree.

5. What is difference between data structures and data types?

 

Data Types	Data Structures
Data Type is the type or perhaps kind of a variable that’s being employed during the entire program. It describes that the specific variable is going to assign the values of the specified data type primarily.	Data Structures in C is the collection of distinct types of data. That overall information could be represented by making use of an object and can be used all throughout the whole program.
Implementation by using Data Types is a type of abstract implementation	Implementation by means of Data Structures in C is referred to as concrete implementation
Could keep values and not data, therefore it is data less	Could store distinct kinds types in one single object
Values can right away be assigned to the data type variables	The data is assigned to the data structures in C in object making use of a few sets of operations and algorithms such as push, pop, etc.
No issue of time complexity	Time complexity comes into play when dealing with data structures in C.
Ex: int, float, double	Ex: stacks, queues, tree

6. What is stack and queue?

• A Stack is a container of items that are placed and then taken out in accordance with the last-in-first-out (LIFO) concept.
• A Queue is a container of items (a linear collection) that are placed and then taken out in accordance with the first-in-first-out (FIFO) concept.

7. What are the 5 properties of an algorithm?

Every Algorithm has to fulfill all of the following conditions –

1. Input: There are many more quantities that are highly provided.
2. Output: A minimum of one quantity is produced.
3. Definiteness: Every instruction of the algorithm must be unambiguous and clear.
4. Finiteness: The procedure must be terminated following a limited number of steps.

Effectiveness: Every instruction should be simple enough for being carried out theoretically or by making use of pen and paper.

8. Why structure is used in C++?

A STRUCT is a C++ data structure that could be implemented to keep collectively the elements of various data types. Within C++, a structure is a user-defined data type. The structure produces a data type for grouping items of various data types within a single data type.

For example:

Assume you have to keep info relating to a person, their age, citizenship, and name. You can make variables such as name, citizenship, and age to keep the details independently.

9. What is graph in C?

A graph comprises a couple of vertices or nodes combined with a set of arcs or edges in which every edge joins 2 vertices. Except if otherwise specified, a graph is undirected. Every edge is an unordered pair u,v of vertices.

So we do not consider either of the 2 vertices as owning a unique task from the other. Nevertheless, it’s a lot more usual in computing to take into account directed graphs or digraphs whereby edges are ordered pairs (u,v). Here vertex u is the origin of the edge and vertex v is the sink or objective of the edge.

10. What is difference between stack and heap?

Stack space is primarily employed for saving the order of local variables and method execution. Stack usually kept blocks in LIFO order in contrast heap memory switched to using dynamic allocation for allocation and for deallocation of memory blocks.