# algorithm-datastructures

Algorithms and Data-structures in Java

#### Given a collection of 1 million integers, all ranging between 1 to 9, sort them in Big O(n) time

###### Upasana | November 22, 2020 | 2 min read | 669 views | algorithm-datastructures

This is a typical Integer Sorting problem with a constraint that the number range to sort is very limited in spite 1 million total entries. Integer Sorting with limited range is achieved efficiently with Bucket Sorting.

#### BlackRock Java Interview Questions

###### Upasana | November 21, 2020 | 1 min read | 1,286 views | algorithm-datastructures

Top Investment Banking Technical Java interview questions asked in Blackrock: algorithms, data structures, design patterns, OOP Design, concurrency, etc.

#### Citibank Java developer interview questions

###### Upasana | November 20, 2020 | 2 min read | 10,921 views | algorithm-datastructures

Java programming interview questions for investment banking domain on Core Java, Multi-threading, Garbage Collection, Design Patterns, Database concepts

#### Top 10 occurring words in a very large file java algorithm

###### Upasana | October 18, 2020 | 4 min read | 422 views | algorithm-datastructures

In this algorithm problem, we will keep track of top 10 occurring words from a very large file using min heap implementation in java

#### Difference between HashMap, LinkedHashMap and TreeMap

###### Upasana | December 04, 2019 | 2 min read | 403 views | algorithm-datastructures

All three classes (HashMap, TreeMap and LinkedHashMap) implements Map interface, and therefore represents mapping from unique key to values.

#### find single repeating number from a big array

###### Upasana | May 05, 2019 | 1 min read | 167 views | algorithm-datastructures

We have an array that contains large number of entries, all of them are unique except one that is repeating twice. We need to find that repeating number in a minimum time & space complexity

#### What is volatile keyword in Java

###### Upasana | May 01, 2019 | 3 min read | 350 views | algorithm-datastructures

The Java volatile keyword means, that every read of a volatile variable will be read from the computer's main memory, and not from the CPU cache, and that every write to a volatile variable will be written to main memory.

#### What are different types of NoSql databases in general?

###### Upasana | April 24, 2019 | 1 min read | 4 views | algorithm-datastructures

We will discuss Document Oriented DB vs Key value pair vs Graph DB in this post