Getting Ready for Interviews in Software Engineering

Prerequisite

Begin by selecting a programming language that you feel comfortable with and that you will use for your interviews. It can be any language, such as Java or Python, as long as you have a solid understanding and knowledge of it.

Data Structures and Algorithms

Acquiring a thorough understanding of popular data structures and algorithms is crucial. I recommend picking up a book like “Data Structures and Algorithms in Java” by Robert Lafore and mastering the fundamentals of data structures and algorithms. Although interviewers may not frequently ask you to implement them, practicing and comprehending their runtime and space complexities is essential.

Doubly Linked List in Data Structures and Algorithms

The linked list concept is used quite commonly in the real world. When we use Spotify to play the next song in the queue, the concept of a single linked list that we learned comes into action. But what exactly can one do to play the previous song in the queue? 

In this blog, we shall understand another concept associated with data structures, which is a Doubly Linked List. We shall also discuss its implementation using C and real-time applications.

Introduction to Data Structures

Data structures are fundamental components of computer programming that allow for the organization and manipulation of data in a manner that is efficient, flexible, and accessible. A data structure is essentially a collection of data items that are organized in a specific way to facilitate their management and utilization within a computer program. There are a wide variety of data structures that have been developed over the years, each with its own unique strengths and weaknesses. 

Data structures are an essential component of computer science and software engineering. They are used to organize and manage data in a way that makes it easy to access, modify and store. Data structures can be broadly categorized into two types - linear and non-linear. Linear data structures are those in which the data elements are arranged in sequential order, while non-linear data structures are those in which the data elements are arranged in a hierarchical or tree-like structure.

Linked List in Data Structures and Algorithms

In the previous blog, we looked into different types of linear data structures. A linked list is also one of them. The program for linked lists seems to be lengthy, but once we are aware of the concept, It's easy to implement it. Linked lists are unlike stack and queues as it stores a pointer pointing to the address. For example, while we are listening to music on Spotify, we can create our song playlist and can play a song from both starting and end of the list. These music players are implemented using a linked list. 

In this blog, we further discuss linked list implementation, how it is related to data structures, and its real-time applications. 

Queue in Data Structures and Algorithms

Queue, for example, is a sequence of people who are standing for buying a metro ticket or ordering food at a store. The first person entering the queue leaves first. Similarly, the last person entering the queue leaves at the last. These queues help in managing the flow of customers and lower the chances of rush while buying. 

In this blog, we further discuss queue implementation, how it is related to data structures, and its real-time applications.

Stack in Data Structures

The word stack is commonly used in general English to address a pile of objects placed vertically. Let us take a few examples, like a pile of coins, a pile of books, or even plates. This pile of objects has the first added things first and the last added things at the end, basically also known as first in, first out. This arrangement is helpful to easily insert objects and pick one.

In this blog, the reader will understand further how stack is related to data structures and its various applications in real life.

C++ Pyramid of numbers: Print numbers that count by two’s and not by one’s

Hello. I am taking a "Data Structures" class. I have to create a code that will print the following "Output":
8 6 4 2 0
6 4 2 0
4 2 0
2 0
0

I tried doing this code three different ways. Here is the first way. I did a similar project in "Java" so I knew I needed a "Nested Loop. I just "re-wrote" the code in "C++" but it does not print the correct numbers. I have to print the numbers in a way that the numbers count by "two's" and not "one's":

for(int i = 8; i >= 1; --i){
    for(int j = 1; j <= i; ++j){
        cout << j << " ";
     }
     cout << endl;
    }
return 0;

Here is the second way. This is incorrect becasue the output prints too many numbers:

for(int count = 8; count >= 1; --count){
    for(int index = 1; index <= count; ++index){
        for (int num = 8; num >= 0; num = num - 2) {
            cout << num << " ";
        }
    }
    cout << endl;
}

Here is the third way. This is incorrect becasue the teacher said this is still considered "Hard Coding" which is not allowed:

 char str[] = "86420 6420 420 20 0";  

 char *token = strtok(str, " "); 

 while (token != NULL) { 
    printf("%s\n", token); 
    token = strtok(NULL, " "); 
  }

return 0; 

My main problem is this (this program seems so simple and I think I have a general idea on how to solve this so I apologize if this question has an easy answer): How do I manipuate the numbers to print "86420" on the first row, "6420" on the second row etc...? I was told that I would need to print these numbers in a "horizontal line" then use a "two level nested loop" to manipulate how the numbers are printed but this is the part I am having trouble with. I can manipulate how the numbers print itself but I can not get the numbers to print correctly.

I tried to find examples of this on "Dani Web" and online but none of them answerd my main question. Please help and thank you in advance to anyone who can help me solve this problem.