10+ Interview Questions and Answers

Search for the minimum element in a rotated sorted array with duplicate elements.

• Use binary search to find the minimum element in the rotated sorted array.

• Handle the case where duplicate elements are present by adjusting the search conditions.

• Consider cases where the array is not rotated or contains only one element.

To create a custom immutable class, use final keyword for class, private final fields, and no setter methods.

• Use the final keyword for the class to prevent inheritance

• Declare all fields as private and final to prevent modification

• Do not provide setter methods for the fields to maintain immutability

• Provide getter methods to access the fields

Remove duplicates from a 1D array of strings in place

• Iterate through the array and use a HashSet to keep track of unique elements

• Replace duplicates with null or an empty string to remove them in place

Spring Actuator provides endpoints to monitor and manage microservices in a Spring Boot application.

• Add Spring Boot Actuator dependency in pom.xml

• Enable Actuator endpoints in application.properties or application.yml

• Access Actuator endpoints like /actuator/health, /actuator/info, etc.

• Customize Actuator endpoints using configuration properties

A singleton class is a class that can only have one instance created throughout the application.

• Declare a private static instance variable of the class

• Create a private constructor to prevent external instantiation

• Provide a public static method to access the instance

String arrays are immutable because they cannot be changed once created.

• Strings in an array cannot be modified individually

• Any changes to a string array result in a new array being created

• Immutable arrays ensure data integrity and prevent unintended side effects

A palindromic substring is a string that reads the same forwards and backwards.

• Use dynamic programming to find the longest palindromic substring.

• Start by considering each character as the center of a potential palindrome.

• Expand outwards from each center to check for palindromes of odd and even lengths.