50+ Amdocs Interview Questions and Answers for Freshers

Given a string of lowercase English letters, find the first non-repeating character at each point in the stream.

• Create a hashmap to store the frequency of each character as it appears in the stream.

• Iterate through the stream and check the frequency of each character to find the first non-repeating character.

• Output the first non-repeating character at each point in the stream.

Check if a Pythagorean triplet exists in a given array of integers.

• Iterate through all possible combinations of three numbers in the array and check if they form a Pythagorean triplet.

• Use a nested loop to generate all possible combinations efficiently.

• Check if the sum of squares of two numbers is equal to the square of the third number.

Check if two strings are anagrams of each other by comparing their sorted characters.

• Sort the characters of both strings and compare them.

• Use a dictionary to count the frequency of characters in each string and compare the dictionaries.

• Ensure both strings have the same length before proceeding with the comparison.

• Example: For input 'spar' and 'rasp', after sorting both strings, they become 'aprs' which are equal, so return True.

Find the total weight of the Minimum Spanning Tree in a graph using Kruskal's algorithm.

• Implement Kruskal's algorithm to find the Minimum Spanning Tree.

• Sort the edges based on their weights and add them to the MST if they don't form a cycle.

• Keep track of the total weight of the MST and return it as the output.

Find the maximum number of points that can be aligned in a straight line on a 2-D plane.

• Iterate through each pair of points and calculate the slope between them.

• Store the slope in a hashmap and keep track of the frequency of each slope.

• The maximum frequency of slopes + 1 gives the maximum number of points on a straight line.

To check for integer overflow when multiplying two integers, use the properties of integer overflow and check if the result is within the valid range of the integer type.

• Check if the signs of the two integers are the same to avoid overflow in case of multiplication.

• Use the properties of integer overflow to detect if the result exceeds the maximum or minimum value of the integer type.

• Consider using a larger data type or a library that supports arbitrary-precision arithmetic if...read more

Challenges faced in RPA experience and how resolved

• One challenge was automating a process with multiple decision points, resolved by creating a decision tree

• Another challenge was handling exceptions, resolved by implementing exception handling mechanisms

• Integration with legacy systems was a challenge, resolved by creating custom connectors

• Lack of standardization in input data was a challenge, resolved by implementing data validation and cleansing mechanisms

Check for a loop in a linked list by using two pointers moving at different speeds.

• Use two pointers, one moving at double the speed of the other.

• If there is a loop, the two pointers will eventually meet at the same node.

• Example: 1 -> 2 -> 3 -> 4 -> 5 -> 2 (loop back to 2), the two pointers will meet at node 2.

Swapping of numbers can be done using call by value, address and reference.

• Call by value: Pass the values of variables as arguments to the function. Swap the values inside the function.

• Call by address: Pass the addresses of variables as arguments to the function. Swap the values using pointers inside the function.

• Call by reference: Pass the references of variables as arguments to the function. Swap the values using references inside the function.

A multi-threading program to print 1 2 1 2 using 2 threads.

• Create two threads and pass a flag to each thread to print either 1 or 2.

• Use a synchronization mechanism like mutex or semaphore to ensure alternate printing.

• Join the threads to wait for their completion.

Design class diagram for Flower shop

• Create a Flower class with attributes like name, color, price, etc.

• Create a Bouquet class that has a list of Flower objects

• Create a Customer class with attributes like name, address, phone number, etc.

• Create an Order class that has a Customer object and a Bouquet object

• Create a Payment class with attributes like payment method, amount, etc.

• Create a Delivery class with attributes like delivery address, delivery date, etc.

Code for binary search algorithm

• Binary search is a divide and conquer algorithm

• It works by repeatedly dividing the search interval in half

• If the value is found, return the index. Else, repeat on the appropriate half

• The array must be sorted beforehand

Reverse a given string

• Use a loop to iterate through the string and append each character to a new string in reverse order

• Alternatively, use built-in string functions like reverse() or slice()

• Remember to handle edge cases like empty strings or strings with only one character

A program that reverses a string input

• Create a function that takes a string as input

• Use a loop to iterate through the characters of the string in reverse order

• Append each character to a new string to build the reversed string

• Return the reversed string as output

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

• Allows a class to reuse code from another class

• Creates a parent-child relationship between classes

• Child class inherits fields and methods from parent class

• Can have multiple levels of inheritance

• Example: class Dog extends Animal

Reverse a given stack of integers using recursion without using extra space or loops.

• Use recursion to pop all elements from the original stack and store them in function call stack

• Once the stack is empty, push the elements back in reverse order using recursion

• Use the top(), pop(), and push() methods to manipulate the stack

The problem involves determining the minimum number of umbrellas required to shelter a specific number of people based on the capacity of each umbrella.

• Iterate through the array of umbrella capacities to find the combination that covers exactly 'M' people.

• Keep track of the minimum number of umbrellas used to cover 'M' people.

• If it is not possible to cover 'M' people exactly, return -1.

• Example: For input [2, 3, 4] and M=5, the minimum number of umbrellas required is 2 (2-capac...read more

Writing a Junit test case for a software engineer interview

• Create a test class that extends TestCase or uses the @Test annotation

• Write test methods that test specific functionality of the code

• Use assertions to verify expected outcomes

• Set up any necessary test data or mocks before running the test

• Use annotations like @Before and @After for setup and teardown tasks

Use SQL query with JOIN to find salaries from 2 tables.

• Use JOIN keyword to combine data from both tables based on a common column

• Specify the columns you want to select from both tables

• Use WHERE clause to filter the results if needed

Bugs, defects, and errors are all issues in software development that can cause problems in the functionality of a program.

• A bug is a coding mistake that causes unexpected behavior in a program.

• A defect is a flaw in the design or functionality of a program.

• An error is a mistake made by a user or a program that causes the program to fail.

• All three can cause issues in the functionality of a program and need to be identified and fixed.

• Examples: A bug could be a typo in the code ...read more

Experiencing a bottleneck during testing can occur when a certain component or process slows down the overall testing progress.

• Identify the root cause of the bottleneck, such as limited resources, inefficient test scripts, or complex test environments.

• Implement strategies to alleviate the bottleneck, such as optimizing test scripts, parallelizing test execution, or allocating more resources.

• Monitor and track the progress after implementing solutions to ensure the bottleneck h...read more

5G is the fifth generation of wireless technology that promises faster internet speeds, lower latency, and increased connectivity.

• 5G stands for fifth generation and is the latest wireless technology

• It promises faster internet speeds, lower latency, and increased connectivity

• 5G uses higher frequency bands and smaller cell sizes to achieve these benefits

• It will enable new technologies like self-driving cars, virtual reality, and the Internet of Things

• Rollout of 5G networks is c...read more

Window functions in SQL are used to perform calculations across a set of rows that are related to the current row.

• Window functions are used to calculate values based on a subset of rows within a table

• They allow you to perform calculations across a set of rows that are related to the current row

• They are often used for running totals, ranking, and moving averages

• Examples of window functions include ROW_NUMBER(), RANK(), and SUM() OVER()

OOPs Concepts include encapsulation, inheritance, polymorphism, and abstraction. Function overloading is having multiple functions with the same name but different parameters. Function overriding is having a derived class redefine a function from its base class.

• Encapsulation: bundling data and methods together

• Inheritance: creating new classes from existing ones

• Polymorphism: using a single interface to represent different types

• Abstraction: hiding implementation details

• Function...read more

Swap 2 numbers without using 3rd variable

• Use addition and subtraction

• Use multiplication and division

• Use bitwise XOR operation

Fiber optics is a technology that uses thin strands of glass or plastic to transmit data as light signals.

• Fiber optics is used in telecommunications to transmit data over long distances.

• It is also used in medical equipment, military technology, and industrial applications.

• Fiber optic cables are made up of thin strands of glass or plastic called fibers.

• These fibers are surrounded by a protective coating and bundled together to form a cable.

• Data is transmitted through the fiber...read more

PFP stands for Plenum Fiber Optic Cable. The size of fiber cable can vary depending on the application and requirements.

• PFP is a type of fiber optic cable that is designed for use in plenum spaces, which are areas used for air circulation in buildings.

• The size of fiber optic cable can range from 0.9mm to 3.0mm in diameter, depending on the number of fibers and the specific application.

• For example, a single-mode fiber optic cable typically has a diameter of 0.9mm, while a mult...read more

Terraform, Packer, and Puppet are tools used in DevOps for infrastructure automation and configuration management.

• Terraform is used for infrastructure as code and automates the provisioning of infrastructure resources.

• Packer is used for creating machine images for multiple platforms from a single source configuration.

• Puppet is used for configuration management and automates the deployment and management of software and configurations across multiple servers.

10 commonly used Linux commands in daily work

• ls - list directory contents

• cd - change directory

• grep - search for a pattern in a file

• tail - display the last part of a file

• cat - concatenate and display files

• chmod - change file permissions

• sudo - execute a command as a superuser

• ps - display information about running processes

• kill - terminate a process

• ssh - connect to a remote server securely

Answering Fibonacci series with and without recursion

• Fibonacci series is a sequence of numbers where each number is the sum of the two preceding ones

• Recursion method involves calling the function within itself

• Non-recursive method involves using a loop to calculate the series

• Recursive method is slower and can cause stack overflow for large inputs

• Non-recursive method is faster and more efficient for large inputs

A materialized view (mview) is a database object that contains the results of a query. Datapump is a tool for moving data between Oracle databases. Oracle GoldenGate is a real-time data integration and replication tool.

• Materialized views (mviews) store the results of a query for faster access.

• Datapump is a tool used for exporting and importing data between Oracle databases.

• Oracle GoldenGate is a real-time data integration and replication tool used for moving and synchronizing...read more

Sort a list in Python

• Use the built-in sorted() function to sort the list in ascending order

• Use the sort() method to sort the list in place

• Use the reverse parameter to sort in descending order

Creditworthiness can be calculated by assessing an individual's financial history, income, debt-to-income ratio, and credit score.

• Evaluate the individual's credit score, which is a numerical representation of their creditworthiness based on their credit history.

• Assess the individual's income to debt ratio to determine their ability to repay debts.

• Review the individual's financial history, including any past bankruptcies or delinquencies.

• Consider other factors such as employme...read more

A pointer is a variable that stores the memory address of another variable.

• Pointers are used to manipulate memory directly.

• They can be used to pass large data structures to functions without copying them.

• Pointers can be used to create dynamic data structures like linked lists and trees.

• They can also be used to access hardware directly.

• Examples of pointer types include int*, char*, and void*.

ASE stands for Average Signal Excess and BAU stands for Business As Usual in the context of RF engineering.

• ASE is a metric used to measure the difference between the received signal strength and the noise floor in a communication system.

• BAU refers to the normal operating conditions or standard practices in a system or organization.

• ASE is important for determining the quality of a signal transmission, while BAU helps in understanding the baseline performance of a system.

• For ex...read more

Print series of prime numbers

• Start with 2 as the first prime number

• Check if each number greater than 2 is divisible by any number less than it

• If not, add it to the list of prime numbers

• Continue until desired number of primes are found

Data analytics is the process of analyzing raw data to draw conclusions and make informed decisions.

• Data analytics involves collecting, processing, and analyzing data to identify trends and patterns.

• It helps organizations make data-driven decisions and improve business performance.

• Examples of data analytics tools include Tableau, Power BI, and Google Analytics.

Implementing a stack using two queues

• Use two queues to simulate a stack

• Push operation: Enqueue the element to queue 1

• Pop operation: Dequeue all elements from queue 1 to queue 2, dequeue the last element from queue 1, then swap the queues

• Top operation: Return the front element of queue 1

• Example: Push 1, 2, 3 - Queue 1: [1, 2, 3], Queue 2: []

• Example: Pop - Queue 1: [1, 2], Queue 2: [3]

Various tools in Excel for data analysis and manipulation.

• Pivot tables for summarizing and analyzing data

• VLOOKUP and HLOOKUP for searching and retrieving specific information

• Conditional formatting for highlighting important data

• Data validation for controlling input values

• Charts and graphs for visualizing data trends

Memory management in Java involves automatic garbage collection, heap and stack memory allocation.

• Java uses automatic garbage collection to manage memory by deallocating objects that are no longer in use.

• Memory in Java is divided into two main areas - heap memory for objects and stack memory for method calls and local variables.

• Java provides methods like System.gc() to suggest garbage collection, but it's ultimately up to the JVM to decide when to run it.

The finalize function is used in Java to perform cleanup operations before an object is garbage collected.

• Finalize method is called by the garbage collector before reclaiming an object's memory.

• It is not recommended to rely on finalize for resource cleanup as it is not guaranteed to be called.

• Example: public void finalize() { // cleanup code }

Different types of joins in SQL are inner join, left join, right join, and full outer join.

• Inner join: Returns rows when there is a 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 either table

Big data refers to large and complex data sets that are difficult to process using traditional data processing applications.

• Big data involves large volumes of data

• It includes data from various sources such as social media, sensors, and business transactions

• Big data requires specialized tools and technologies for processing and analysis

Spark is a distributed computing framework that processes big data in memory and is known for its speed and ease of use.

• Spark is a distributed computing framework that can process data in memory for faster processing.

• It uses Resilient Distributed Datasets (RDDs) for fault-tolerant distributed data processing.

• Spark provides high-level APIs in Java, Scala, Python, and R for ease of use.

• It supports various data sources like HDFS, Cassandra, HBase, and S3 for data processing.

• Spar...read more

DBMS stands for Database Management System. It is a software system that manages and organizes data in a database.

• DBMS is used to create, modify, and delete databases and their objects.

• It provides a way to store and retrieve data efficiently.

• It ensures data integrity and security.

• Examples of DBMS include Oracle, MySQL, and Microsoft SQL Server.