Barco Electronic Systems Sdet (Software Development Engineer in Test) Interview Questions and Answers

Reverse a linked list

• Iterate through the linked list and change the direction of the pointers

• Use three pointers to keep track of the current, previous, and next nodes

• Make sure to update the head and tail pointers accordingly

Swap 2 numbers without using a third variable

• Use the XOR operation to swap the numbers

• Assign the first number to the second number using XOR

• Assign the second number to the first number using XOR

Height of a binary tree is the maximum number of edges from the root node to any leaf node.

• The height of an empty tree is 0.

• The height of a tree with only one node is 1.

• The height of a tree can be calculated recursively by finding the height of its left and right subtrees and adding 1 to the maximum of the two heights.

• The time complexity of finding the height of a binary tree is O(n), where n is the number of nodes in

Sum queries on a 2D matrix

• Iterate through each query and calculate the sum of elements in the given range

• Use prefix sum technique to optimize the solution

• Preprocess the matrix to store the sum of elements in each row and column for faster calculation

4 pillars of OOPs: Abstraction, Encapsulation, Inheritance, Polymorphism.

• Abstraction: Hiding implementation details and showing only necessary information.

• Encapsulation: Binding data and functions together and restricting access to them.

• Inheritance: Creating new classes from existing ones, inheriting properties and methods.

• Polymorphism: Ability of objects to take on multiple forms or behaviors.

Implement a queue using stack

• Use two stacks, one for enqueue and one for dequeue

• When dequeue is called, pop all elements from enqueue stack and push to dequeue stack

• Then pop from dequeue stack to get the first element added to the queue

• When enqueue is called, simply push the element to enqueue stack