Round-1 (Hackerrank Test): 4 coding questions:

• Implement HashMap using LinkedList. In this HashMap, on addition, the old value should not get replaced with the new one for a particular key.
• On inputting any number (98267), print "number". On inputting number+chars (123abc), throw custom-made exception "AlphaNumericException", and for chars (abc), throw custom-made exception "StringException".
• Even count numbers sum in an array.
• Array with maximum prime numbers.

Round-2 (Technical): Interview Mode: Zoom Video. Focus was mainly on Data Structures and Java Multithreading.

• Core Java questions. Difference between two methods of creating a thread.
• Write code in Java for printing even numbers from one thread and odd numbers from another in a synchronized way.
• Write a function to return the minimum number of jumps to reach the end of the array (starting from the first element).
• Write a function to print the day on which stock should be bought and the day on which stock should be sold to maximize profit, given the stock prices for each day in an array.

Round-3 (Managerial): Interview Mode: Zoom Video. Focus was on Data Structures, Multithreading, Core Java, SQL, and Microservices.

• Find the only missing number in a sorted array.
• Find pairs with a given sum in an array.
• Write a Java program which adds the values in a list through one thread and removes through another in a synchronized way, with some restrictions.
• SQL question.
• Annotations in Spring Boot.

Round-4 (HR): This was telephonic.

Best part was that the results of all the rounds were declared on the same day itself the interview was conducted.

Implement HashMap using LinkedList. In this HashMap, on addition, the old value should not be replaced with the new one for a particular key.

On inputting any number (98267), print "number". On inputting number+chars (123abc), throw a custom-made exception "AlphaNumericException", and for chars (abc), throw a custom-made exception "StringException".

Calculate the sum of even count numbers in an array.

Find the array with the maximum prime numbers.

Explain the difference between two methods of creating a thread.

Write code in Java for printing even numbers from one thread and odd numbers from another in a synchronized way.

Write a function to return the minimum number of jumps to reach the end of the array (starting from the first element).

Write a function to print the day on which stock should be bought and the day on which stock should be sold to maximize profit, given the stock prices for each day in an array.

Difference between the throw and throws keywords in Java? What happens when an exception is thrown by a catch block and also by a finally block? The exception from which block is thrown ultimately by the function?

Method overriding: Can we override a static method in Java?

Explain the internal working of HashMap.

Given table:

id 1001 1002 1003 2001 2002 2003 ...

Print rows with IDs that do not start with 1 or 2, except for 1002 and 2001.

Find the only missing number in a sorted array.

Find pairs with a given sum in an array.

Write a Java program which adds values to a list through one thread and removes them through another in a synchronized way, with some restrictions.