Koo App Sde1 Interview Questions and Answers

A doubly-linked list is a data structure where each node contains a reference to both the previous and next nodes.

• Allows traversal in both directions

• Used in implementing LRU cache

• Used in browser history

• Used in undo-redo functionality

Doubly linked list allows traversal in both directions, while singly linked list only allows traversal in one direction.

• Doubly linked list allows for efficient deletion of nodes compared to singly linked list.

• Doubly linked list can be traversed in both forward and backward directions.

• Doubly linked list can be used to implement a stack or queue.

• Singly linked list requires less memory than doubly linked list.

• Doubly linke...read more

Graph data structure is used in various applications such as social networks, routing algorithms, and recommendation systems.

• Social networks use graphs to represent users and their connections.

• Routing algorithms use graphs to find the shortest path between two points.

• Recommendation systems use graphs to analyze user behavior and suggest relevant items.

• Graphs are also used in computer networks, image processing, and mac...read more

In-memory DB stores data in RAM for faster access while MySQL stores data on disk.

• In-memory DB is faster than MySQL as it eliminates disk I/O operations.

• In-memory DB is suitable for real-time applications that require low latency.

• MySQL is suitable for applications that require data persistence and durability.

• In-memory DB may not be suitable for large datasets as it requires a lot of RAM.

• MySQL supports complex queries a...read more

RDBMS is a structured database that uses SQL while NoSQL is a non-relational database that doesn't use SQL.

• RDBMS stores data in tables with predefined schema while NoSQL stores data in documents, key-value pairs, or graphs.

• RDBMS is good for complex queries and transactions while NoSQL is good for scalability and handling unstructured data.

• Examples of RDBMS include MySQL, Oracle, and SQL Server while examples of NoSQL i...read more

Indexing is the process of organizing data in a database or search engine to improve search efficiency.

• Indexing creates a data structure that allows for faster retrieval of information.

• It involves creating an index that maps the location of data in a database or search engine.

• Indexing can be done on various types of data, such as text, numbers, and dates.

• Examples of indexing methods include B-tree, hash, and bitmap ind...read more

The question is unclear and requires clarification.

• The question is not specific about what 'above question' it is referring to.

• The term 'internal working' is also vague and needs to be defined.

• Without more information, it is impossible to provide a meaningful answer.

Print internal nodes of a binary tree (excluding left and right view nodes)

• Traverse the tree in post-order and check if the node has both left and right children

• If yes, then it is an internal node and print it

• If no, then continue traversing the tree

• Example: For the tree 1-2-4-5-3, the internal nodes are 2 and 4