Greenway Health Data Engineer Interview Questions and Answers

OOPS is a programming paradigm based on the concept of objects, which can contain data in the form of fields and code in the form of procedures.

• OOPS focuses on the concept of classes and objects

• Encapsulation: bundling data and methods that operate on the data within a single unit

• Inheritance: allows a class to inherit properties and behavior from another class

• Polymorphism: ability to present the same interface for diffe...read more

Comparable is an interface used for natural ordering, Comparator is an interface used for custom ordering. Abstract class can have method implementations, Interface cannot.

• Comparable interface is used to define the natural ordering of objects. Example: String class implements Comparable interface for natural ordering based on alphabetical order.

• Comparator interface is used to define custom ordering of objects. Example:...read more

Count occurrences of each character in a given string

• Create an array to store the count of each character

• Iterate through the string and increment the count of each character in the array

• Return the array with counts for each character

Remove duplicates from an array of strings

• Iterate through the array and store each element in a set to keep track of unique values

• Create a new array with the unique values from the set

The container with most water problem involves finding the maximum area that can be formed between two vertical lines by selecting two points on a line.

• Start with two pointers at the beginning and end of the array.

• Calculate the area between the two pointers using the formula min(height[left], height[right]) * (right - left).

• Move the pointer with the smaller height towards the center to potentially increase the area.

• Rep

Find the maximum subarray with a sum of 0 in an array.

• Iterate through the array and keep track of the running sum.

• Store the running sum in a hashmap along with the index.

• If the running sum is seen again, the subarray between the two occurrences has a sum of 0.

Iterator and generator are used in Python to iterate over a sequence of elements. .pyc files are compiled Python files.

• Iterator in Python is an object that enables a programmer to traverse a container, like a list.

• Generator in Python is a function that returns an iterator. It generates values using the yield keyword.

• Example of iterator: for num in range(5): print(num)

• Example of generator: def square_numbers(n): for i i...read more

Bug life cycle is the process of identifying, reporting, fixing, retesting, and closing bugs in a software project.

• Bug is identified by a tester during testing phase

• Bug is reported to the development team

• Development team fixes the bug

• Tester retests the bug to ensure it is fixed

• Bug is closed once confirmed fixed

Sort an array of strings in descending order

• Use the sort() method with a custom compare function to sort the array in descending order

• Example: ['apple', 'banana', 'cherry'].sort((a, b) => b.localeCompare(a)) will result in ['cherry', 'banana', 'apple']