20+ Classic Marble Company Interview Questions and Answers

Sort the list of strings based on the last character, then second last character, and so on.

• Iterate through each string in the list

• Sort the strings based on the last character first, then second last character, and so on

• Use a custom sorting function to achieve the required sorting order

Calculate the count of distinct elements in each sliding window of size 'K' across an array 'ARR'.

• Use a sliding window approach to iterate through the array and keep track of distinct elements using a hashmap or set.

• Update the count of distinct elements in each window as it slides across the array.

• Return the array detailing the count of distinct elements in each 'K' sized window for each test case.

Given a list of key numbers in sequentially numbered boxes, help Alex determine the box containing the correct key.

• Iterate through the list of key numbers and compare each with the target key number.

• Use binary search for efficient search in the sorted list of key numbers.

• Return the box number if the correct key is found, otherwise indicate that it is not present.

Maximize vaccines administered on a specific day while following certain rules.

• Iterate through each test case and calculate the maximum number of vaccines distributed on the specified day.

• Distribute vaccines in a way that the difference between consecutive days is at most 1 and the total does not exceed the maximum allowed.

• Ensure to maximize the number of vaccines administered on the specified day.

• Return the maximum number of vaccines administered on the specified day for eac...read more

Reverse a given string containing alphabets, numbers, and special characters.

• Iterate through the string from end to start and append each character to a new string.

• Alternatively, use built-in functions like reverse() or slicing to reverse the string.

• Handle special characters and numbers while reversing the string.

• Ensure to consider the constraints on the length of the string and number of test cases.

Rearrange an array such that all zero elements appear at the beginning, followed by non-zero elements, maintaining relative order of non-zero elements.

• Iterate through the array and maintain two pointers - one for the next position to place a zero and one for the next non-zero element.

• Swap the elements at these pointers until all zeros are moved to the left and non-zero elements are in their relative order.

• Time complexity: O(N), Space complexity: O(1)

• Example: Input: [1, 1, 0, ...read more

Check if the numbers on the left diagonal are the same as those on the right diagonal of a square matrix.

• Iterate through the matrix to compare the numbers on the left and right diagonals.

• Keep track of the numbers on both diagonals and check for equality.

• Return 'true' if the diagonals are equal, otherwise return 'false'.

Sort a Singly Linked List using Merge Sort algorithm.

• Implement the Merge Sort algorithm for linked lists.

• Divide the list into two halves, sort each half recursively, and then merge them.

• Use a fast and slow pointer to find the middle of the list for splitting.

• Handle the base cases of empty list or single node list.

• Example: Input: 4 3 2 1 -1, Output: 1 2 3 4

Generate a pattern of characters in increasing order based on the number of rows specified.

• Iterate through each row from 1 to N

• For each row, print the corresponding character repeated row number of times

• Increment the character for each row

SQL query to find the second highest salary from a table

• Use the MAX() function to find the highest salary

• Use the NOT IN operator to exclude the highest salary from the results

• Order the salaries in descending order and limit the result to 1

There are 5 types of inheritance: single, multiple, multilevel, hierarchical, and hybrid.

• Single inheritance: A class inherits from a single base class.

• Multiple inheritance: A class inherits from multiple base classes.

• Multilevel inheritance: A class inherits from a derived class, which in turn inherits from another class.

• Hierarchical inheritance: Multiple classes inherit from a single base class.

• Hybrid inheritance: Combination of multiple and multilevel inheritance.

Reverses the order of elements in an array stored in a linked list.

• Traverse the linked list and store the elements in an array

• Reverse the array using two pointers

• Update the linked list with the reversed array

Code implementing inheritance

• Inheritance is a concept in object-oriented programming where a class inherits properties and methods from another class

• The class that is being inherited from is called the parent class or base class

• The class that inherits from the parent class is called the child class or derived class

• The child class can access the properties and methods of the parent class

• Inheritance promotes code reusability and allows for creating specialized classes based on ...read more

Iterative solution to perform preorder traversal without using recursion

• Use a stack to keep track of nodes

• Start by pushing the root node onto the stack

• While the stack is not empty, pop a node, visit it, then push its right child followed by its left child onto the stack

4 pillars of OOPs are Abstraction, Encapsulation, Inheritance, and Polymorphism. TCP/IP and OSI models are networking models.

• 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 their properties and methods.

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

• TCP/IP model: Consists of...read more

Malware is a broad term that includes viruses, which are a specific type of malware. Python code can be used to identify IP addresses in malware analysis.

• Malware is a general term for any type of malicious software, while viruses are a specific type of malware that self-replicates by inserting copies of itself into other computer programs.

• Python code can be used to extract and analyze IP addresses from malware samples, helping analysts understand the network infrastructure us...read more

To rotate a matrix 90 degrees, transpose the matrix and then reverse each row.

• Transpose the matrix by swapping matrix[i][j] with matrix[j][i]

• Reverse each row of the transposed matrix to get the final rotated matrix

Diamond problem is a common issue in multiple inheritance where a class inherits from two classes that have a common ancestor.

• Occurs in languages that support multiple inheritance like C++

• Results in ambiguity when calling methods or accessing attributes from the common ancestor class

• Can be resolved using virtual inheritance or interfaces

Run length encoding is a data compression technique that replaces repeated characters with a count and single character.

• Iterate through the input array of strings

• Count the number of consecutive characters in each string

• Replace consecutive characters with count and character

Rotate an array of strings by d times

• Create a new array and copy elements from original array based on rotation index

• Use modulo operator to handle cases where d is greater than array length

• Handle edge cases like empty array or d being negative