Reliable Hubs Engineering Interview Questions and Answers

Program to print even and odd numbers using two threads in Java

• Create two threads, one for even numbers and one for odd numbers

• Use a loop to generate numbers and check if they are even or odd

• Print the numbers using the respective threads

• Use synchronization to ensure alternate printing of even and odd numbers

HashMap is a data structure that stores key-value pairs and uses hashing to retrieve values.

• HashMap uses an array of buckets to store key-value pairs

• The hash code of the key is used to determine the index of the bucket

• If multiple keys have the same hash code, they are stored in a linked list within the bucket

• HashMap allows null keys and values

• HashMap is not thread-safe and requires synchronization for concurrent access

flatMap in Java 8 is a method used to transform each element of a stream into another stream and then concatenate all the streams into a single stream.

• flatMap is used to flatten nested collections in streams.

• It is commonly used with streams of collections or arrays.

• Example: List> list = Arrays.asList(Arrays.asList(1, 2), Arrays.asList(3, 4)); list.stream().flatMap(Collection::stream).forEach(System.out::println);

LCA of a node in BST is the lowest common ancestor of two nodes in a binary search tree.

• Traverse the BST from the root node to find the LCA of the given nodes.

• Compare the values of the nodes with the current node to determine the LCA.

• If one node is on the left subtree and the other is on the right subtree, the current node is the LCA.

final is a keyword in Java used to declare constants, while finally is a block used in exception handling to ensure code is executed regardless of an exception.

• final keyword is used to declare constants in Java

• final variables cannot be reassigned once initialized

• finally block is used in exception handling to ensure code is executed regardless of an exception

• finally block is often used to release resources like closing a file or database connection