Fidelity Investments Associate Software Engineer Interview Questions and Answers

To check palindrome and anagram of a string with O(n), use a hash table to store character frequencies.

• Create a hash table to store the frequency of each character in the string.

• For palindrome, check that no more than one character has an odd frequency.

• For anagram, compare the hash tables of the two strings.

• If the hash tables are equal, the strings are anagrams.

• If the hash tables differ by only one character, the strin...read more

Optimized solutions and core principles applied in OOPS

• Encapsulation, Inheritance, Polymorphism, Abstraction are core principles of OOPS

• Optimized solutions can be achieved through efficient algorithms and data structures

• Design patterns like Singleton, Factory, Observer can also be used for optimized solutions

Yes, the string class can be extended in most programming languages.

• Inheritance can be used to extend the functionality of the string class.

• By creating a new class that inherits from the string class, additional methods and properties can be added.

• Extending the string class allows for customization and adding specific functionality to strings.

• Example: In Python, the string class can be extended by creating a new class ...read more

Implicit objects in JSP are predefined objects that are available for use without any declaration or initialization.

• Implicit objects in JSP include request, response, session, application, out, config, pageContext, page, exception, and others.

• These objects provide access to various aspects of the JSP environment and can be used to perform common tasks.

• For example, the request object allows access to HTTP request parame...read more

A hash map is a data structure that uses a hash function to map keys to values.

• Hash map stores key-value pairs

• It uses a hash function to compute an index for each key

• Collisions can occur when two keys hash to the same index

• Hash maps provide fast access to values based on their keys

StringBuffer and StringBuilder are both used to manipulate strings, but StringBuffer is thread-safe while StringBuilder is not.

• StringBuffer is synchronized, making it safe for use in multi-threaded environments.

• StringBuilder is not synchronized, making it faster but not thread-safe.

• StringBuffer is preferred when multiple threads are involved, while StringBuilder is preferred for single-threaded scenarios.

• Both classes p...read more

Annotations used in RESTful web services

• 1. @Path - Specifies the URI path for the resource

• 2. @GET - Specifies that the method handles HTTP GET requests

• 3. @POST - Specifies that the method handles HTTP POST requests

• 4. @PUT - Specifies that the method handles HTTP PUT requests

• 5. @DELETE - Specifies that the method handles HTTP DELETE requests

• 6. @PathParam - Binds the value of a URI template parameter to a method paramete...read more

Code for rand7 using rand5 function

• Use rand5 twice to generate a number in [1,25] with equal probability

• If the number is greater than 21, discard and try again

• Otherwise, return (number mod 7) + 1