Mettl Sdet Engineer Interview Questions and Answers

Delete nodes in linkedlist with greater value on right side

• Traverse the linked list from right to left

• Compare each node with the maximum value seen so far

• If the current node has a greater value, delete it

• Update the maximum value seen so far

Check if given tree is BST or not

• A binary tree is a BST if the value of each node is greater than all the values in its left subtree and less than all the values in its right subtree

• Perform an in-order traversal of the tree and check if the values are in ascending order

• Alternatively, for each node, check if its value is within the range defined by its left and right subtrees

OOP is a programming paradigm that organizes code into objects with properties and behaviors.

• OOP stands for Object-Oriented Programming.

• It focuses on creating reusable code by organizing it into objects.

• Objects have properties (attributes) and behaviors (methods).

• Encapsulation, inheritance, and polymorphism are key principles of OOP.

• Example: In Java, a class represents an object with its properties and methods.

Runtime polymorphism is when the method to be executed is determined at runtime, while compile-time polymorphism is determined at compile-time.

• Runtime polymorphism is achieved through method overriding.

• Compile-time polymorphism is achieved through method overloading.

• Runtime polymorphism is also known as dynamic polymorphism.

• Compile-time polymorphism is also known as static polymorphism.

• Runtime polymorphism is associate...read more

Virtual functions are functions in a base class that can be overridden by derived classes to provide different implementations.

• Virtual functions are declared in a base class and can be overridden in derived classes.

• They allow polymorphism, where a pointer to a base class can invoke different derived class implementations.

• Virtual functions are resolved at runtime based on the actual object type.

• They are used to achieve

An abstract class is a class that cannot be instantiated and is meant to be subclassed.

• An abstract class can have both abstract and non-abstract methods.

• It can provide a common interface for its subclasses.

• Subclasses of an abstract class must implement all the abstract methods.

• Abstract classes can have constructors.

• An abstract class cannot be instantiated directly, but its subclasses can be.

Inheritance is a mechanism in object-oriented programming where a class inherits properties and behaviors from another class.

• Inheritance allows code reuse and promotes code organization.

• There are different types of inheritance: single inheritance, multiple inheritance, multilevel inheritance, hierarchical inheritance, and hybrid inheritance.

• Single inheritance involves a class inheriting from a single base class.

• Multipl...read more

Print Fibonacci series less than or equal to 1000.

• Start with two variables, a and b, initialized to 0 and 1 respectively.

• Print a and update a to the value of b, and b to the sum of the previous a and b.

• Repeat until a exceeds 1000.

The sum of even numbers in the Fibonacci series is calculated.

• Generate the Fibonacci series up to a given limit

• Iterate through the series and check if each number is even

• If the number is even, add it to the sum

• Return the sum of the even numbers

Stacks are a data structure that follows the Last-In-First-Out (LIFO) principle.

• Stacks have two main operations: push (adds an element to the top) and pop (removes the top element).

• Stacks can be implemented using arrays or linked lists.

• Common applications of stacks include function call stack, undo/redo operations, and expression evaluation.

• Example: A stack of books, where the last book placed is the first one to be re

Implement max() function to find the maximum element in a stack with optimized time and space complexity.

• Use an additional stack to keep track of the maximum element at each step.

• When pushing an element onto the stack, compare it with the top element of the maximum stack and push the larger one.

• When popping an element from the stack, also pop the top element from the maximum stack if they are equal.

• The top element of t...read more