Pegasystems L.S.A Interview Questions and Answers

HashMap is not thread-safe while ConcurrentHashMap is thread-safe and allows concurrent modifications.

• HashMap is not thread-safe and can lead to ConcurrentModificationException if modified concurrently.

• ConcurrentHashMap allows concurrent modifications without the need for external synchronization.

• ConcurrentHashMap achieves thread-safety by dividing the map into segments, allowing multiple threads to operate on differen...read more

Load balancers distribute incoming network traffic across multiple servers to ensure no single server is overwhelmed.

• Load balancers monitor the health of servers and distribute traffic based on predefined algorithms.

• They can be hardware-based or software-based.

• Common algorithms used by load balancers include round-robin, least connections, and IP hash.

• Load balancers can improve reliability and scalability of a website ...read more

The Two Sum problem involves finding two numbers in an array that add up to a target value.

• Iterate through the array and store the difference between the target and current element in a hashmap.

• Check if the current element exists in the hashmap, if yes, return the indices of the current element and the stored difference.

• Time complexity of O(n) can be achieved by using a hashmap to store elements and their indices.

Correct mislabelled jars by relabelling them with correct labels.

• Identify the mislabelled jars

• Check the correct labels for each jar

• Remove the mislabelled label

• Apply the correct label to the jar

• Ensure all jars are correctly labelled

Reverse a number using recursion.

• Define a recursive function that takes the number as input

• Base case: if the number is less than 10, return the number

• Recursive case: return the last digit of the number concatenated with the result of calling the function with the number divided by 10

• Call the function with the input number