Modi Motors Agencies Interview Questions and Answers

Semaphores, OSI layers, deadlock and ACID protocols in DBMS

• Semaphores are used for process synchronization and communication

• OSI model has 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, Application

• Deadlock protocols prevent processes from entering a deadlock state

• ACID protocols ensure database transactions are reliable and consistent

Linear data structures have a sequential arrangement of elements while non-linear data structures have a hierarchical arrangement.

• Linear data structures have a fixed number of elements and are easy to traverse.

• Non-linear data structures have an arbitrary number of elements and are difficult to traverse.

• Arrays, linked lists, and stacks are examples of linear data structures.

• Trees, graphs, and heaps are examples of non-linear data structures.

C++ is an extension of C with object-oriented programming features.

• C++ supports classes and objects while C does not.

• C++ has better support for polymorphism and inheritance.

• C++ has a standard template library (STL) for data structures and algorithms.

• C++ allows function overloading while C does not.

• C++ has exception handling while C does not.

Steps for client server connection request.

• Client sends a connection request to the server.

• Server receives the request and sends a response.

• Client receives the response and establishes a connection.

• Connection is maintained until terminated by either party.

Boundary traversal of a binary tree is the process of visiting the nodes on the boundary of the tree.

• Start with the root node and traverse the left boundary nodes from top to bottom.

• Traverse the leaf nodes from left to right.

• Traverse the right boundary nodes from bottom to top.

• Exclude the leaf nodes that are already traversed in the second step.

• Repeat the above steps for all the subtrees of the binary tree.

The left view of a binary tree shows the nodes that are visible when the tree is viewed from the left side.

• Traverse the tree recursively from left to right

• Print the first node encountered at each level

• Example: For tree with root node A, left view is A, B, D, G

To find the middle of a linked list, use two pointers - one moving at twice the speed of the other.

• Use two pointers - slow and fast

• Slow pointer moves one node at a time, fast pointer moves two nodes at a time

• When fast pointer reaches the end, slow pointer will be at the middle

Processes are independent programs while threads are lightweight processes within a program.

• Processes have their own memory space while threads share memory space.

• Processes communicate through inter-process communication while threads communicate directly.

• Processes are slower to create and terminate than threads.

• Examples of processes are web browsers, word processors, etc. while examples of threads are spell checkers, print spoolers, etc.