70+ Specialist Programmer Interview Questions and Answers

Find the first occurrence of target value in a sorted array with duplicates.

• Use binary search to find the target value.

• If found, check if the previous element is also the target value.

• If not, return the index of the target value.

• If yes, continue binary search on the left subarray.

Find the maximum subarray sum in an array with positive and negative integers.

• Use Kadane's algorithm to find the maximum subarray sum.

• Initialize two variables, one for current maximum and one for global maximum.

• Iterate through the array and update the variables accordingly.

• Return the global maximum.

• Example: [-2, 1, -3, 4, -1, 2, 1, -5, 4] returns 6 (subarray [4, -1, 2, 1])

Process scheduling algorithms determine the order in which processes are executed by the CPU.

• First Come First Serve (FCFS) - Processes are executed in the order they arrive.

• Shortest Job Next (SJN) - Process with the shortest burst time is executed next.

• Round Robin (RR) - Each process is assigned a fixed time slice for execution.

• Priority Scheduling - Processes are executed based on priority levels assigned to them.

• Multi-Level Queue Scheduling - Processes are divided into diffe...read more

Deadlock in OS occurs when two or more processes are unable to proceed because each is waiting for the other to release a resource.

• Deadlock happens when processes have acquired resources but are waiting for additional resources that are held by other processes.

• Four conditions must hold for deadlock to occur: mutual exclusion, hold and wait, no preemption, and circular wait.

• Deadlock can be prevented by using techniques like resource allocation graphs, deadlock detection algori...read more

Design a path for visiting all popular places of your city.

• Identify all popular places in the city

• Group them based on their proximity to each other

• Create a route that covers all groups in an efficient manner

• Consider transportation options and time of day

• Include breaks for meals and rest

• Test the route to ensure it is feasible and enjoyable

Joins in DBMS are used to combine rows from two or more tables based on a related column between them.

• Inner Join: Returns rows when there is at least one match in both tables.

• Left Join: Returns all rows from the left table and the matched rows from the right table.

• Right Join: Returns all rows from the right table and the matched rows from the left table.

• Full Outer Join: Returns rows when there is a match in one of the tables.

• Self Join: Joining a table with itself to combine r...read more

Inheritance is a concept in object-oriented programming where a class inherits properties and behaviors from another class.

• Types of inheritance: single inheritance, multiple inheritance, multilevel inheritance, hierarchical inheritance, hybrid inheritance

• Single inheritance: a class inherits from only one base class

• Multiple inheritance: a class inherits from multiple base classes

• Multilevel inheritance: a class inherits from a class which in turn inherits from another class

• Hier...read more

Code to convert camel casing to snake casing and vice versa.

• For camel to snake case, iterate through the string and add '_' before every uppercase letter except the first one.

• For snake to camel case, iterate through the string and remove '_' and capitalize the letter after it.

• Handle edge cases like consecutive uppercase letters or underscores in the input string.

• Use built-in string functions like split(), join(), and replace() for efficient implementation.

Sorting code for given 3 RAMs and data quantity

• Determine the size of each RAM and the quantity of data in them

• Choose a sorting algorithm based on the size of data and available RAM

• Divide the data into chunks that can fit into the available RAM

• Sort each chunk using the chosen algorithm

• Merge the sorted chunks into a single sorted list

Design a promise wrapper with timeout for resolving or rejecting a promise function.

• Create a function that takes a promise function and timeout value as parameters.

• Inside the function, create a new Promise that wraps the original promise function.

• Use Promise.race to race between the original promise and a timeout promise.

• If the original promise resolves before timeout, resolve the wrapper promise with the result.

• If the original promise rejects or the timeout occurs first, rej...read more

Virtual DOM manipulation is faster in React due to its ability to batch updates and minimize actual DOM operations.

• Virtual DOM allows React to batch multiple updates into a single operation, reducing the number of actual DOM manipulations needed.

• React compares the virtual DOM with the actual DOM and only updates the parts that have changed, instead of re-rendering the entire DOM.

• Virtual DOM operations are performed in memory, which is faster than directly manipulating the act...read more

Three drawbacks of pandas are performance issues with large datasets, limited visualization capabilities, and lack of built-in support for time series analysis.

• Performance can be slow with large datasets due to pandas being memory intensive

• Limited visualization capabilities compared to tools like Matplotlib or Seaborn

• Lack of built-in support for time series analysis, requiring additional libraries like Statsmodels or Prophet

I have utilized various cloud processes including deployment, data storage, and serverless computing in my projects.

• Implemented CI/CD pipelines using AWS CodePipeline for automated deployments.

• Utilized AWS S3 for scalable data storage and backup solutions.

• Developed serverless applications using AWS Lambda to reduce infrastructure management.

• Leveraged Azure Functions for event-driven processing in real-time applications.

• Used Google Cloud Pub/Sub for asynchronous messaging betw...read more

A Binary Search Tree (BST) is a data structure that maintains sorted order for efficient searching, insertion, and deletion.

• A BST is a tree where each node has at most two children.

• The left child contains values less than the parent node.

• The right child contains values greater than the parent node.

• Example: Inserting 10, 5, 15 results in a tree with 10 as root, 5 as left child, and 15 as right child.

• Searching for a value starts at the root and traverses left or right based on ...read more

Program to print frequencies of elements in an array.

• Create a dictionary to store the frequency of each element.

• Iterate through the array and update the frequency in the dictionary.

• Print the dictionary to display the frequency of each element.

Dijkstra's Algorithm finds the shortest path in graphs, useful for navigation, logistics, and network routing.

• 1. Navigation Systems: Used in GPS to find the shortest route between two locations.

• 2. Network Routing: Helps in determining the most efficient data packet paths in computer networks.

• 3. Logistics: Optimizes delivery routes for transportation companies to minimize travel time and costs.

• 4. Urban Planning: Assists in designing efficient public transport routes by analyzi...read more

Count the frequency of elements in an array.

• Iterate through the array and use a hash table to keep track of the frequency of each element.

• Alternatively, use a dictionary in Python or a map in C++ to achieve the same result.

• If the array is sorted, you can use binary search to find the first and last occurrence of each element and calculate the frequency.

• Time complexity can be improved to O(n) using a modified counting sort algorithm.

To swap two numbers without using third variable, use arithmetic operations.

• Add the two numbers and store the result in the first variable.

• Subtract the second variable from the sum and store the result in the second variable.

• Subtract the second variable from the original sum and store the result in the first variable.

JavaScript is a dynamic scripting language, while TypeScript is a statically typed superset of JavaScript.

• JavaScript is dynamically typed, while TypeScript is statically typed.

• TypeScript supports type checking at compile time, while JavaScript does not.

• TypeScript allows for the use of interfaces and advanced OOP features, while JavaScript does not.

• TypeScript code needs to be transpiled to JavaScript before it can be executed in a browser.

Search an element in sorted 2d matrix.

• Start from the top right corner or bottom left corner and move towards the target element

• If the current element is greater than target, move left. If it's smaller, move down

• Repeat until target is found or all elements are traversed

Find the largest increasing subsequence from a list of natural numbers

• Use dynamic programming to keep track of the longest increasing subsequence ending at each index

• Iterate through the list and update the longest increasing subsequence for each element

• Return the maximum length of the increasing subsequence

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Normalization involves breaking down data into smaller, more manageable tables and establishing relationships between them.

• It helps in reducing data redundancy and inconsistencies.

• There are different normal forms such as 1NF, 2NF, 3NF, BCNF, and 4NF.

• For example, in a database of students and courses, instead of storing all student details in the same table as course d...read more

Immutability in Python refers to the property of objects that cannot be changed after creation.

• Immutable objects cannot be modified once created

• Immutable objects include numbers, strings, and tuples

• Immutable objects are useful for caching and as dictionary keys

Monolith vs microservice architecture pros and cons

• Monolith: easier to develop and test, simpler deployment process

• Monolith: can be harder to scale and maintain as it grows

• Microservices: scalable and flexible, easier to update and maintain

• Microservices: complex to develop and deploy, requires more monitoring and management

• Example: Monolith - traditional web applications, Example: Microservices - Netflix, Amazon

Dynamic Programming (DP) is a method for solving complex problems by breaking them down into simpler subproblems.

• DP is used in optimization problems, like the Knapsack problem.

• Example: Finding the longest increasing subsequence in an array.

• DP can be implemented using memoization or tabulation techniques.

• Example: Fibonacci sequence can be computed efficiently using DP.

Array list has O(1) time complexity for accessing elements but O(n) for insertion/deletion, while linked list has O(n) time complexity for accessing elements but O(1) for insertion/deletion.

• Array list has constant time complexity O(1) for accessing elements by index, but linear time complexity O(n) for insertion/deletion operations due to shifting elements.

• Linked list has linear time complexity O(n) for accessing elements as it requires traversing from the head node, but cons...read more

The staircase problem involves finding the number of ways to climb stairs with given steps.

• Dynamic Programming Approach: Use an array to store the number of ways to reach each step.

• Base Cases: For 0 stairs, there's 1 way (stay put); for 1 stair, there's also 1 way (one step).

• Recurrence Relation: To reach step n, you can come from step n-1 or n-2, so dp[n] = dp[n-1] + dp[n-2].

• Example: For 3 stairs, ways = dp[3] = dp[2] + dp[1] = 2 + 1 = 3 (ways: 1-1-1, 1-2, 2-1).

• Time Complexit...read more