NatWest Software Developer 1 Interview Questions and Answers

The question asks to input an array and print the repeating characters.

• Iterate through the array and store each element in a hash table or dictionary.

• If an element already exists in the hash table, it is a repeating character.

• Print all the repeating characters found.

Program to find the second minimum in an array.

• Sort the array and return the second element.

• Initialize two variables to store minimum and second minimum values.

• Loop through the array and update the variables accordingly.

To find the longest palindrome in a given string.

• Iterate through the string and check for palindromes of odd and even lengths.

• Keep track of the longest palindrome found so far.

• Use two pointers to check if the substring is a palindrome.

• If the substring is a palindrome and its length is greater than the current longest palindrome, update the longest palindrome.

Find the next higher number with equal number of ones in binary representation.

• Convert input number to binary

• Count number of ones in binary representation

• Increment input number until binary representation has equal number of ones

• Convert incremented number to decimal

Find the duplicate number in an array of 10 numbers with only 2 steps.

• Use a hash set to keep track of visited numbers.

• Iterate through the array and check if the number is already in the set.

• If it is, then it is the duplicate number.

• If not, add it to the set.

• At the end, the duplicate number will be found.

Program to print elements of a linked list in reverse order using same single linked list

• Traverse the linked list and push each element onto a stack

• Pop elements from the stack and print them in reverse order

To check the occurrence and correctness of HTML tags, we can use various tools and techniques.

• One way is to use a browser's developer tools to inspect the HTML code and see the tags and their frequency.

• Another way is to use an online HTML validator tool that checks for correct syntax and tag usage.

• We can also use programming languages like Python to parse HTML and count the occurrence of each tag.

• Regular expressions ca...read more

Reverse a linked list using iterative and recursive methods.

• Iterative method involves traversing the list and changing the pointers to reverse the order.

• Recursive method involves calling the function recursively on the next node and changing the pointers.

• Both methods have O(n) time complexity and O(1) space complexity.

• Example: 1->2->3->4->5 becomes 5->4->3->2->1.

Clone a linked list with a random pointer.

• Create a new node for each node in the original list.

• Use a hash table to map the original nodes to their clones.

• Iterate through the original list again and update the random pointers of the clone nodes.

Machine learning is a subset of artificial intelligence that enables machines to learn from data without being explicitly programmed.

• It involves training algorithms on large datasets to make predictions or decisions.

• It can be supervised, unsupervised, or semi-supervised.

• Examples include image recognition, natural language processing, and recommendation systems.

Prediction uses data analysis and statistical models to forecast future outcomes.

• Prediction involves collecting and analyzing data to identify patterns and trends.

• Statistical models are then used to make predictions based on the identified patterns.

• Predictions can be made for a wide range of applications, such as weather forecasting, stock market trends, and customer behavior.

• Accuracy of predictions can be improved by ...read more

Classification algorithms can be represented using flow charts.

• Classification algorithms are used to categorize data into different classes.

• Flow charts can be used to represent the decision-making process of classification algorithms.

• Examples of classification algorithms include decision trees, k-nearest neighbors, and support vector machines.

Deadlocks are situations where two or more processes are unable to proceed because each is waiting for the other to release a resource.

• Deadlocks occur when multiple processes are stuck in a circular waiting state.

• Prevention techniques include resource allocation strategies, deadlock detection, and avoidance algorithms.

• Examples of prevention techniques are using a resource allocation graph, implementing a banker's algor...read more

Banker's algorithm is a resource allocation and deadlock avoidance algorithm used in operating systems.

• It is used to prevent deadlocks by ensuring that the system never enters an unsafe state.

• It works by simulating the allocation of resources and checking if the system will remain in a safe state.

• It requires knowledge of the maximum resource needs of each process and the currently available resources.

• If a request for r...read more

Public and private IP addresses are used in computer networks. Public IPs are globally unique and accessible from the internet, while private IPs are used within a local network.

• Public IP is assigned by the Internet Service Provider (ISP) and is used to identify a device on the internet.

• Private IP is assigned by a local network administrator and is used to identify a device within a local network.

• Public IPs are globall...read more

A message is transferred in OSI layer through a process called encapsulation and decapsulation.

• The message is divided into smaller chunks called packets at the transport layer.

• Each packet is then encapsulated with headers containing necessary information.

• The encapsulated packets are then passed down to the network layer.

• At the network layer, the packets are further encapsulated with network layer headers.

• The encapsulat...read more

Polymorphism is the ability of an object to take on many forms. It allows objects of different classes to be treated as the same type.

• Polymorphism is achieved through method overriding and method overloading.

• It allows for code reusability and flexibility in object-oriented programming.

• Three conditions for polymorphism are inheritance, method overriding, and a common interface or base class.

Interoperability in inheritance and polymorphism allows objects of different classes to be used interchangeably.

• Inheritance allows a subclass to inherit properties and methods from a superclass.

• Polymorphism allows objects of different classes to be treated as if they are of the same class.

• Interoperability between inheritance and polymorphism allows objects of different classes to be used interchangeably.

• For example, a ...read more

Transaction logs are records of all the changes made to a database or file system.

• They help in recovering data in case of system failure or errors.

• They provide a history of all the transactions made to the database or file system.

• They are used for auditing and compliance purposes.

• Examples include SQL Server transaction logs, file system transaction logs, etc.

C is a procedural programming language while C++ is an object-oriented programming language.

• C is a procedural programming language, meaning it focuses on procedures or functions.

• C++ is an extension of C and adds object-oriented features like classes and inheritance.

• C++ supports polymorphism, encapsulation, and abstraction, which C lacks.

• C++ allows the use of standard template library (STL) for data structures and algor...read more

I have worked on various technologies including Java, Python, and SQL.

• Java - used for developing enterprise-level applications

• Python - used for scripting, web development, and data analysis

• SQL - used for managing and querying databases

Thrashing is a phenomenon in computer systems where excessive swapping of data between RAM and virtual memory occurs.

• Occurs when a computer spends more time swapping data between RAM and virtual memory than executing actual tasks

• Can be caused by insufficient RAM or poorly optimized programs

• Can lead to a significant decrease in system performance

• Example: A computer running multiple memory-intensive programs simultaneous

Java is platform independent while C++ is not.

• Java code is compiled into bytecode which can run on any platform with a JVM, while C++ code needs to be compiled separately for each platform.

• Java has automatic memory management through garbage collection, while C++ requires manual memory management.

• Java has built-in support for multithreading, while C++ requires external libraries.

• Java has a simpler syntax and is easier ...read more

Persistence is important for storing data permanently and ensuring data integrity.

• Persistent storage allows data to be saved even after the application is closed or the system is restarted.

• It ensures data integrity by preventing data loss in case of system failures.

• Persistent data can be accessed and shared across different sessions or devices.

• Examples: databases, file systems, cloud storage.

I found the GD to be well-organized and productive.

• The GD had a clear agenda and all participants were given equal opportunity to express their views.

• The facilitator ensured that the discussion stayed on track and encouraged active participation.

• I appreciated the diverse perspectives brought by the participants, which enriched the discussion.

• Examples: One of the participants shared a real-life case study that added dep...read more

I rate my HR interview as positive overall, with room for improvement in certain areas.

• Overall, I felt the HR interview was well-structured and professional.

• I appreciated the opportunity to discuss my skills and experiences in depth.

• However, I felt that some questions were repetitive and could have been more engaging.

• I believe the interview process could benefit from more focus on technical skills and problem-solving a...read more

I would recommend John and Sarah for their strong technical skills and ability to work well in a team.

• John has a deep understanding of algorithms and data structures, and consistently delivers high-quality code.

• Sarah is a quick learner and has a knack for problem-solving, often coming up with innovative solutions.

• Both John and Sarah have excellent communication skills and collaborate effectively with their peers.