BlackRock Interview Questions

What is the square root of 1498?

Given a list of objects, use the Stream API to group the objects based on the 'place' attribute. Then, convert this logic to equivalent SQL code.

Explain the assumptions of linear regression.

Write the algorithm for bubble sort.

How would you implement a Set data structure?

Swap two values without using a temporary variable.

Suppose we have three fair dice and we toss them in order. What is the probability that the outcome is strictly increasing? For example, (1, 3, 5) and (3, 5, 6) are allowed, but (4, 3, 5) is not.

You are given two buckets: one holds 3 litres and the other holds 5 litres. How would you measure exactly 4 litres using only these two buckets?

How do you write an infinite loop in a programming language of your choice?

Given a directed acyclic graph (DAG), find the length of the longest path in the graph.

What is serialization in Java?

What is the 'finally' block in Java, and when is it used?

Given a string, find the length of the longest substring that contains only unique characters.

Describe the differences between a left outer join and a right outer join in database systems.

Implement a stack using two queues.

Explain how you would design a Minesweeper game in Java.

You are performing a regression of Y on X and observe that the variability of the residuals is unequal across the range of X. What can you infer from this?

If you have three rolls of a die, and after the first and second rolls you can choose either to accept your current roll or roll again, what is the optimal strategy to maximize your final roll, and what is the expected value of your outcome?

What is the angle between the hour hand and the minute hand at 12:15 on a standard clock?

Reverse a string in Java.

Describe Principal Component Analysis (PCA).

Write an algorithm that sorts a hashmap.

Given a string, determine if it is a palindrome, ignoring any characters that are not alphabetic.

1) Reverse a number: Given an integer input, output its digits in reverse order. For example, input: 9966, output: 6699. 2) Word count in a string: Given a string, return the count of each unique word. For example, input: 'The lovely lady is looking lovely as all lady look lovely' output: The: 1, lovely: 3, lady: 2, is: 1, looking: 1, as: 1, all: 1, look: 1. 3) Swap two numbers without using a temporary variable: Given two numbers, swap their values without using a third variable. For example, input: a = 10, b = 20. Output: a = 20, b = 10.

Solve the intersection of two linked lists from scratch, including implementing the linked list data structure. Start with a brute-force approach and optimize it. Also, explain the difference between arrays and linked lists.

Given a singly linked list, find and return the value of the middle node.

1) Find the nth node from the end of a linked list. 2) Find the second largest number in an array.

Given a binary search tree (BST) and a target value, write an algorithm to determine if the value exists in the BST.

Write an algorithm that returns the Nth number in the Fibonacci sequence.

Write a function that returns the median value from a given list of numbers.