40+ Mehta Jaising Developers Interview Questions and Answers

A prime number is a number that is divisible only by 1 and itself.

• A prime number has exactly two factors: 1 and itself.

• Prime numbers cannot be divided evenly by any other number.

• Examples of prime numbers include 2, 3, 5, 7, 11, 13, 17, etc.

Methods to find nth largest element in an unsorted linked list

• Traverse the linked list and store elements in an array, sort the array and return the nth largest element

• Use quickselect algorithm to find the nth largest element in O(n) time complexity

• Implement a max heap and extract the nth largest element

• Divide the linked list into smaller sublists and recursively find the nth largest element

• Use merge sort to sort the linked list and return the nth largest element

Hashing is a process of converting data into a fixed-size numerical value called a hash code.

• Hashing is used to quickly retrieve data from large datasets.

• It is commonly used in data structures like hash tables and hash maps.

• Hash functions should be fast, deterministic, and produce unique hash codes for different inputs.

• Examples of hash functions include MD5, SHA-1, and SHA-256.

Design classes for educational institutions in a city

• Identify the main entities: schools, students, teachers, courses

• Create a School class with attributes like name, address, and a list of students and teachers

• Create a Student class with attributes like name, age, and a list of courses

• Create a Teacher class with attributes like name, specialization, and a list of courses

• Create a Course class with attributes like name, duration, and a list of students and teachers

• Establish rel...read more

The question asks for the number of pairs between 1 and N that satisfy a specific mathematical relation.

• The relation is pow(a,3) + pow(b,3) = pow(c,3) + pow(d,3)

• The values of a, b, c, and d should be less than or equal to N

• Count the number of pairs that satisfy the relation

Check if a given file path exists in the file system hierarchy and return the result.

• Use file system APIs to check if the given file path exists in the hierarchy.

• Traverse the file system hierarchy starting from the root directory to find the given file path.

• Return true if the file path exists, false otherwise.

Abstraction is hiding the implementation details, function overriding is providing a new implementation for a method in a subclass.

• Abstraction involves hiding the complex implementation details and showing only the necessary features to the user.

• Function overriding occurs in inheritance when a subclass provides a specific implementation for a method that is already defined in its superclass.

• Example: Parent class 'Animal' has a method 'makeSound()', subclass 'Dog' overrides th...read more

Test cases for a bank transaction

• Transaction amount within account balance limit

• Transaction amount exceeds account balance limit

• Transaction to a valid account number

• Transaction to an invalid account number

• Transaction with correct transaction code

• Transaction with incorrect transaction code

• Transaction during bank working hours

• Transaction outside bank working hours

Finding optimal path cost and path in a matrix using dynamic programming.

• Dynamic programming is a technique to solve problems by breaking them down into smaller subproblems and solving them recursively.

• In this case, we can use dynamic programming to find the optimal path cost and path in a matrix.

• We can start by defining a 2D array to store the minimum cost of reaching each cell in the matrix.

• Then, we can use a recursive function to calculate the minimum cost of reaching the ...read more

Dijkstra's algorithm finds the shortest path between nodes in a graph.

• Create a graph with nodes and edges

• Assign a tentative distance to each node

• Set the initial node as current and mark it visited

• For each neighbor of the current node, calculate the tentative distance

• If the tentative distance is less than the current distance, update the distance

• Mark the current node as visited and select the unvisited node with the smallest tentative distance

• Repeat until the destination node ...read more

A program to reverse a singly linked list

• Create a new empty linked list

• Traverse the original linked list and insert each node at the beginning of the new list

• Return the new list

To find a cycle in a graph, use depth-first search (DFS) and keep track of visited nodes.

• Implement DFS algorithm to traverse the graph

• Maintain a visited array to keep track of visited nodes

• If a visited node is encountered again during DFS, a cycle exists

MongoDB is scalable due to its ability to horizontally partition data across multiple servers.

• MongoDB uses sharding to distribute data across multiple servers.

• Sharding allows for horizontal scaling by adding more servers to the cluster.

• MongoDB also supports replica sets for high availability and fault tolerance.

• Indexes can be created on any field in a MongoDB document, allowing for efficient querying of large datasets.

Paypal is a digital payment platform that allows individuals and businesses to make online transactions.

• Paypal provides a secure way to send and receive money online.

• It allows users to link their bank accounts, credit cards, or debit cards to their Paypal account.

• Users can make payments to merchants or individuals using their Paypal balance or linked payment methods.

• Paypal offers buyer and seller protection, dispute resolution, and fraud prevention services.

• It is widely used ...read more

Encryption of code involves converting plaintext into ciphertext to secure data.

• Choose a strong encryption algorithm like AES or RSA

• Generate a key for encryption

• Encrypt the plaintext using the key and algorithm

• Store or transmit the ciphertext securely

Detecting loop in a linked list

• Use two pointers, one moving one node at a time and the other moving two nodes at a time

• If there is a loop, the two pointers will eventually meet

• If any of the pointers reach the end of the list, there is no loop

Merge sort is a divide-and-conquer algorithm that recursively divides an array into two halves, sorts them, and then merges them.

• Divide the array into two halves

• Recursively sort each half

• Merge the sorted halves back together

• Repeat until the entire array is sorted

DFS (Depth-First Search) is a graph traversal algorithm that explores as far as possible along each branch before backtracking.

• DFS uses a stack to keep track of visited nodes and explore adjacent nodes.

• It can be implemented recursively or iteratively.

• DFS is useful for solving problems like finding connected components, detecting cycles, and solving mazes.

Rotten oranges problem involves finding the minimum time required to rot all oranges in a grid.

• Use Breadth First Search (BFS) to traverse the grid and update the ripening time of neighboring oranges.

• Keep track of the fresh oranges and the time taken to rot them all.

• Handle edge cases like no fresh oranges or unreachable oranges.