100+ Diligenta 2 Interview Questions and Answers

The game is not fair.

• Player X has a higher chance of winning as they only need to get a consecutive HEAD, TAIL.

• Player Y needs to get a consecutive HEAD, HEAD which is less likely to occur.

• The probability of Player X winning is higher than Player Y winning.

The last ball that will be left is black.

• When you take out 2 black balls, you take another white ball.

• If you take 2 white balls, you take out 1 black ball.

• If balls are of different color, you take out another black ball.

• Since there are more black balls initially, the last ball will be black.

Design a website similar to bookmyshow.com for booking cinema tickets for a single location with multiple theatres.

• Design a user-friendly GUI with options for advance booking, user login, user registration, movie rating, and saving card details.

• Create relevant database tables to store information about movies, theatres, bookings, user details, and card details.

• Link the GUI to the database to enable data flow and retrieval.

• Implement features like advance booking, where users c...read more

The program prints the substring after a specified character has occurred a certain number of times in a given string.

• Iterate through the string to find the specified character.

• Keep track of the count of occurrences of the character.

• Once the count reaches the specified count, extract the substring after that position.

• Handle corner cases such as when the character is not in the string or when it doesn't occur the specified number of times.

Minimum number of times to turn all glasses upside down when 4 can be turned at a time.

• Turn over any four glasses, leaving one untouched.

• Repeat the above step until only one glass is left upside down.

• Finally, turn over the last glass to complete the task.

• Minimum number of turns required is 3.

Print all possible paths from start to end in a linear way, moving either one or two steps right.

• Use dynamic programming to solve the problem

• Create a 2D array to store the number of paths to each position

• Start from the end position and work backwards

• At each position, calculate the number of paths by summing the number of paths from the next two positions

• Print all the paths by backtracking from the start position

The code inserts two numbers in a text file, ensuring that the second number is greater than the first and there is no overlap between entries.

• Read the existing entries from the text file

• Check if the new numbers satisfy the conditions

• If conditions are met, insert the new numbers into the file

• Otherwise, display an error message

Code to find the middle element of a linked list

• Traverse the linked list with two pointers, one moving twice as fast as the other

• When the fast pointer reaches the end, the slow pointer will be at the middle element

• If the linked list has even number of elements, return the second middle element

Code to count the number of times '1' occurs from 1 to 999999

• Loop through all numbers from 1 to 999999

• Convert each number to a string and count the number of '1's in it

• Add the count to a running total

• Return the total count

The code prints the transpose of a given matrix.

• Iterate through each row and column of the matrix.

• Swap the elements at the current row and column with the elements at the current column and row.

• Print the transposed matrix.

Arrange 4 coins to make maximum number of triangles

• Place 3 coins in a triangle formation and the fourth coin in the center to form 4 triangles

• Place 2 coins on top of each other and the other 2 coins on either side to form 2 triangles

• Place 2 coins in a line and the other 2 coins on either side to form 2 triangles

Arrange 10 coins in 4 rows of 4 coins each.

• Place 4 coins in a row and keep the remaining 6 aside.

• Place 3 coins from the remaining 6 in the next row and keep the remaining 3 aside.

• Place 2 coins from the remaining 3 in the third row and keep the remaining 1 aside.

• Place the last coin in the fourth row along with the remaining 1 coin from step 3.

• The final arrangement will have 4 rows with 4 coins each.

Multitasking is the ability of an operating system to run multiple tasks concurrently while multiprogramming is the ability to run multiple programs concurrently.

• Multitasking allows multiple tasks to run concurrently on a single processor system.

• Multiprogramming allows multiple programs to run concurrently on a single processor system.

• Multitasking is achieved through time-sharing, where the processor switches between tasks at a very high speed.

• Multiprogramming is achieved thr...read more

Microcontroller is a self-contained system with memory, peripherals and processor, while microprocessor only has a processor.

• Microcontroller has on-chip memory and peripherals, while microprocessor requires external memory and peripherals.

• Microcontroller is used in embedded systems, while microprocessor is used in general-purpose computing.

• Examples of microcontrollers include Arduino, PIC, and AVR, while examples of microprocessors include Intel Pentium, AMD Ryzen, and ARM Co...read more

Yes, an array can have elements of different data types.

• An array can have elements of different data types, but it's not recommended.

• It can make the code harder to read and maintain.

• For example, an array can have both strings and numbers: ['apple', 5, 'banana']

Circular doubly linked list is a data structure where each node has a reference to both the next and previous nodes, forming a circular loop.

• Create a Node class with data, next, and prev pointers

• Implement operations like insert, delete, search, and display

• Ensure the last node's next pointer points to the first node and the first node's prev pointer points to the last node

Searching and sorting algorithms are essential in programming for efficiently organizing and retrieving data.

• Searching algorithms: linear search, binary search, depth-first search, breadth-first search

• Sorting algorithms: bubble sort, selection sort, insertion sort, merge sort, quick sort

• Examples: Searching for a specific item in a list, sorting a list of numbers in ascending order

Modified Balanced Parentheses where characters can be matched with any other character.

• Use a stack to keep track of opening characters

• When encountering a closing character, check if it matches the top of the stack

• If it matches, pop from the stack, else return false

• Continue until end of string, return true if stack is empty

Print all possible combinations of strings by picking one character from each string in the array.

• Iterate through each character of the first string and combine it with each character of the second string.

• Repeat the process for all strings in the array to get all possible combinations.

• Use nested loops to generate combinations efficiently.

A linked list is a linear data structure where each element is a separate object linked together by pointers.

• Linked list is used to implement stacks, queues, and hash tables.

• It is used in computer memory allocation.

• It is used in image processing to represent pixels.

• It is used in music player to create a playlist.

• It is used in web browsers to store the history of visited web pages.

Data structures are ways of organizing and storing data in a computer so that it can be accessed and used efficiently.

• Data structures can be linear or non-linear

• Examples of linear data structures include arrays, linked lists, and stacks

• Examples of non-linear data structures include trees and graphs

• Choosing the right data structure is important for optimizing performance and memory usage

Java program to calculate date n days after given date without using Date parsing libraries.

• Parse the input date string to extract day, month, and year components.

• Calculate the total number of days represented by the input date.

• Add the specified number of days to the total days calculated.

• Convert the final total days back to day, month, and year components to get the new date.

Find the largest element in a window of size K in an array.

• Iterate through the array and maintain a deque to store the indices of elements in decreasing order.

• Remove indices from the front of the deque that are outside the current window.

• The front of the deque will always have the index of the largest element in the current window.

My phone uses iOS. Other phone operating systems available in the market are Android, Windows, and Blackberry OS.

• iOS is developed by Apple and is exclusive to iPhones and iPads.

• Android is developed by Google and is used by various phone manufacturers such as Samsung, LG, and HTC.

• Windows is developed by Microsoft and is used by Nokia and other phone manufacturers.

• Blackberry OS is developed by Blackberry and is exclusive to Blackberry phones.

Transactions in a bank involve the movement of funds between accounts or the exchange of currency.

• Transactions can be initiated by customers or by the bank itself

• Common types of transactions include deposits, withdrawals, transfers, and loans

• Transactions are recorded in the bank's ledger and may be subject to fees or interest

• Electronic transactions have become increasingly popular, such as online banking and mobile payments

Use backtracking to find all combinations of numbers in an array that sum up to a given number.

• Start by sorting the array in non-decreasing order to easily identify combinations.

• Use backtracking to recursively find all combinations that sum up to the target number.

• Keep track of the current combination and the remaining sum as you traverse the array.

• Add the current combination to the result when the sum equals the target number.

Remove duplicates from array of strings while maintaining original order.

• Iterate through the array and use a Set to keep track of unique elements.

• Add elements to a new array only if they are not already in the Set.

SQL query using joins

• Use JOIN keyword to combine rows from two or more tables based on a related column between them

• Types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column

Print Pythagorean triplets within a given range.

• Iterate through all possible combinations of a, b, and c within the given range

• Check if a^2 + b^2 = c^2 for each combination

• Print the triplets that satisfy the Pythagorean theorem

Design a Tic Tac Toe game

• Create a 3x3 grid to represent the game board

• Allow two players to take turns marking X and O on the grid

• Check for win conditions after each move to determine the winner

• Handle tie game if all spaces are filled without a winner

Check if a string has balanced parentheses.

• Use a stack to keep track of opening parentheses.

• Iterate through the string and push opening parentheses onto the stack.

• When a closing parenthesis is encountered, pop from the stack and check if it matches the closing parenthesis.

• If stack is empty at the end and all parentheses are matched, the string has balanced parentheses.

I recently downloaded VLC media player.

• Visited the official website of VLC media player

• Clicked on the download button

• Selected the appropriate version for my operating system

• Waited for the download to complete

• Opened the downloaded file and followed the installation wizard

Around 600 flights are handled by Bangalore airport on a daily basis.

• Bangalore airport is one of the busiest airports in India

• It handles both domestic and international flights

• On average, there are around 25-30 flights per hour

• The number of flights may vary depending on the day of the week and time of the year

Finding common elements in two sorted linked lists.

• Traverse both lists simultaneously using two pointers.

• Compare the values of the nodes pointed by the two pointers.

• If they are equal, add the value to the result list and move both pointers.

• If not, move the pointer pointing to the smaller value.

• Repeat until one of the lists is fully traversed.

Static variables can be accessed from non-static methods using an object reference or by making the variable non-static.

• Static variables can be accessed from non-static methods by creating an object of the class containing the static variable.

• Alternatively, the static variable can be made non-static to be accessed directly from a non-static method.

• Attempting to access a static variable directly from a non-static method will result in a compilation error.

Two objects created - one in the string pool and one in the heap.

• String 'a' is created in the string pool, while String 'b' is created in the heap.

• String pool is a special area in the heap memory where strings are stored to increase reusability and save memory.

• Using 'new' keyword always creates a new object in the heap, even if the content is the same as an existing string in the pool.

Only the original string 'Something' will be garbage collected.

• The concat method in Java does not modify the original string, but instead returns a new string with the concatenated value.

• In this case, 'a' remains as 'Something' and a new string 'Something New' is created, but not assigned to any variable.

• Since the new string is not stored in any variable, it will not be garbage collected.

Delete nth node from end of linked list

• Use two pointers, one to traverse the list and another to keep track of the nth node from the end

• Once the nth node is reached, move both pointers until the end of the list

• Delete the node pointed by the second pointer

Merge and remove duplicates from two sorted arrays without using Collections

• Use two pointers to iterate through both arrays simultaneously

• Compare elements at each pointer and add the smaller one to the result array

• Skip duplicates by checking if the current element is equal to the previous element

Finding the Kth element after merging two sorted arrays.

• Merge the two sorted arrays into a single array.

• Sort the merged array.

• Return the Kth element from the merged and sorted array.

HAVING clause is used with GROUP BY to filter groups, WHERE clause is used to filter rows.

• HAVING clause is used with GROUP BY clause to filter groups based on aggregate functions.

• WHERE clause is used to filter rows based on conditions.

• HAVING clause is used after GROUP BY clause, while WHERE clause is used before GROUP BY clause.

• HAVING clause can use aggregate functions, while WHERE clause cannot.

• Example: SELECT category, COUNT(*) FROM products GROUP BY category HAVING COUNT(*...read more

Inheritance in OOP allows a class to inherit properties and behaviors from another class.

• Inheritance promotes code reusability by allowing a new class to use the properties and methods of an existing class.

• The class that is being inherited from is called the base class or parent class, while the class that inherits is called the derived class or child class.

• Derived classes can add new properties and methods, or override existing ones from the base class.

• Example: class Animal ...read more

OOPs stands for Object-Oriented Programming. It is a programming paradigm based on the concept of objects.

• OOPs is a way of organizing and designing code around objects

• It emphasizes on encapsulation, inheritance, and polymorphism

• It helps in creating reusable and modular code

• Examples of OOPs languages are Java, C++, Python, etc.

Emulate Producer/Consumer Problem using code

• Create a shared buffer between producer and consumer

• Use synchronization mechanisms like mutex or semaphore to control access to the buffer

• Implement producer and consumer functions to add and remove items from the buffer respectively

PL/SQL is a procedural language designed specifically for the Oracle Database management system.

• PL/SQL is used to create stored procedures, functions, triggers, and packages in Oracle databases.

• It is a block-structured language that allows developers to write code in logical blocks.

• PL/SQL supports data types such as VARCHAR2, NUMBER, DATE, BOOLEAN, etc.

• It also supports control structures like IF-THEN-ELSE, FOR LOOP, WHILE LOOP, etc.

• PL/SQL can be used to manipulate data in Ora...read more

Sort an array of strings based on their frequency of occurrence.

• Create a frequency map to count the occurrences of each string

• Sort the strings based on their frequency in descending order

• If two strings have the same frequency, sort them lexicographically

• Return the sorted array

Function overloading is having multiple functions with the same name but different parameters. Function overriding is redefining a function in a subclass.

• Function overloading allows multiple functions with the same name but different parameters.

• Function overriding involves redefining a function in a subclass with the same name and parameters as in the superclass.

• Example of function overloading: int add(int a, int b) and float add(float a, float b)

• Example of function overridin...read more

The Camel Banana problem is a puzzle that involves calculating the number of bananas a camel can eat.

• The problem involves a camel that can carry a certain weight and a number of bananas with different weights.

• The camel can only carry a maximum weight and can only eat a certain number of bananas.

• The goal is to determine the maximum number of bananas the camel can eat without exceeding its weight limit.

Rotate a linked list

• Create a new node and make it the head

• Traverse the list to find the tail and connect it to the old head

• Update the tail to point to null

• Handle edge cases like empty list or rotating by 0 positions

Creating a deadlock involves two or more threads waiting for each other to release a resource they need.

• Create two threads, each trying to lock two resources in a different order

• Ensure that one thread locks resource A first and then tries to lock resource B, while the other thread locks resource B first and then tries to lock resource A

• This will result in a situation where each thread is waiting for the other to release the resource it needs, causing a deadlock

Implement LRU Cache using a data structure like LinkedHashMap in Java

• Use LinkedHashMap to maintain insertion order

• Override removeEldestEntry method to limit cache size

• Update the access order on get and put operations

Calculate the product of all elements in an array except for the element itself.

• Iterate through the array and calculate the product of all elements except the current element.

• Use two separate arrays to store the product of elements to the left and right of the current element.

• Multiply the corresponding elements from the left and right arrays to get the final result.

To divide a cake into 8 parts with only 3 cuts, make two perpendicular cuts to create 4 equal pieces, then cut each of those pieces in half.

• Make a horizontal cut across the middle of the cake to create 2 equal halves.

• Make a vertical cut through the middle of the cake to create 4 equal quarters.

• Make a diagonal cut through each quarter to create 8 equal parts.

Program to separate strong for special characters in an array of strings

• Iterate through each string in the array

• For each string, iterate through each character

• Check if the character is a special character and separate it into a new string if it is

POJO is a Plain Old Java Object with private fields and public getters/setters, while a Bean is a Java class with private fields and public zero-argument constructors.

• POJO stands for Plain Old Java Object

• POJO has private fields and public getters/setters

• Bean is a Java class with private fields and public zero-argument constructors

• Beans are usually used in Java EE frameworks like Spring for dependency injection

Code to start 5 threads in Java

• Create a class that implements the Runnable interface

• Instantiate 5 objects of the class

• Create 5 threads using the objects and start them

Code to read a file in Java

• Use FileReader and BufferedReader classes to read the file

• Handle exceptions using try-catch blocks

• Close the file after reading using close() method

Find the second highest occurrence of a vowel in a string.

• Iterate through the string and count the occurrences of each vowel (a, e, i, o, u).

• Store the counts in an array and find the second highest count.

• Return the vowel with the second highest count.

Singleton pattern ensures a class has only one instance and provides a global point of access to it.

• Ensures a class has only one instance by providing a global access point to it.

• Uses a private constructor to restrict instantiation of the class.

• Provides a static method to access the singleton instance.

• Commonly used in scenarios where only one instance of a class is needed, such as database connections or logging.

• Example: Singleton pattern can be implemented in Java using a pr...read more

To count the number of links on a web page, you can use a web scraping tool or inspect the page's HTML code.

• Use a web scraping tool like BeautifulSoup or Selenium to extract all the links from the webpage.

• Inspect the HTML code of the webpage and look for anchor tags () which contain the links.

• Count the number of anchor tags to determine the total number of links on the webpage.

Use CSS selector to locate element on webpage

• Use unique id or class names to locate element

• Use CSS selectors like 'id', 'class', 'name', 'tag name', etc.

• Use XPath if necessary for complex element locating

Normalization to BCNF ensures that every non-trivial functional dependency is satisfied.

• Identify all functional dependencies

• Eliminate partial dependencies

• Eliminate transitive dependencies

• Ensure every determinant is a candidate key

Code quality can be measured through various metrics and tools to ensure readability, maintainability, efficiency, and reliability.

• Use code review processes to assess adherence to coding standards and best practices

• Utilize static code analysis tools to identify potential bugs, code smells, and security vulnerabilities

• Measure code complexity using metrics like cyclomatic complexity and maintainability index

• Track code coverage with unit tests to ensure adequate test coverage

• Mon...read more