American Express Collections Executive Interview Questions and Answers for Experienced

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

Different types of risk in finance include market risk, credit risk, liquidity risk, operational risk, and legal risk.

• Market risk refers to the potential for losses due to changes in market conditions, such as fluctuations in interest rates, exchange rates, or stock prices.

• Credit risk is the risk of default by borrowers or counterparties, leading to potential losses for lenders or investors.

• Liquidity risk is the risk o...read more

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

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

MVC is a software architectural pattern that separates an application into three main components: Model, View, and Controller.

• Model represents the data and business logic of the application.

• View is responsible for displaying the user interface.

• Controller handles user input, updates the model, and interacts with the view.

• MVC promotes separation of concerns and modularity in software development.

• Example: In a web applica...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

Top 5 customers of HSBC can be found by analyzing transaction history and account balances.

• Analyze transaction history of all HSBC customers worldwide

• Identify customers with highest transaction volumes and account balances

• Rank customers based on transaction volumes and account balances

• Select top 5 customers based on ranking

• Consider other factors such as creditworthiness and profitability

Use online maps or directories to find the number of petrol pumps in the city.

• Search for petrol pumps on online maps like Google Maps or MapQuest.

• Use online directories like Yelp or Yellow Pages to find petrol pumps in the city.

• Check with local authorities or city websites for a list of petrol pumps in the area.

• Ask locals or taxi drivers for recommendations on petrol pumps in the city.

The average number of people coming to the airport daily can be calculated by taking the total number of people arriving and departing and dividing it by two.

• Collect data on the number of arrivals and departures for a given period, such as a week or a month.

• Add the number of arrivals and departures together to get the total number of people coming to the airport.

• Divide the total number by the number of days in the peri...read more