HackerRank Solutions

Welcome to my HackerRank journey. Here are presented 172 HackerRank solutions using Java 8.

About This Project

This project was done using Eclipse (Neon 3) IDE and Java 8.

Profiles

HackerRank.

LinkedIn.

Solutions

Java

Subdomain	Difficulty	Points	Challenge	Solution
Advanced	Easy	010	Java Exception Handling (Try-catch)	Solution
Advanced	Easy	015	Java Exception Handling	Solution
Advanced	Easy	015	Java Factory Pattern	Solution
Advanced	Easy	015	Java Reflection - Attributes	Solution
Advanced	Easy	015	Java Singleton Pattern	Solution
Advanced	Easy	015	Java Varargs - Simple Addition	Solution
Advanced	Easy	020	Covariant Return Types	Solution
Advanced	Medium	015	Can You Access?	Solution
Advanced	Medium	025	Java Annotations	Solution
Advanced	Medium	025	Prime Checker	Solution
Advanced	Medium	030	Java Lambda Expressions	Solution
Advanced	Medium	030	Java MD5	Solution
Advanced	Medium	030	Java SHA-256	Solution
Advanced	Medium	040	Java Visitor Pattern	Solution
BigNumber	Easy	010	Java BigInteger	Solution
BigNumber	Easy	020	Java Primality Test	Solution
BigNumber	Medium	020	Java BigDecimal	Solution
Data Structures	Easy	005	Java 1D Array	Solution
Data Structures	Easy	010	Java 2D Array	Solution
Data Structures	Easy	010	Java Arraylist	Solution
Data Structures	Easy	010	Java Hashset	Solution
Data Structures	Easy	010	Java Map	Solution
Data Structures	Easy	010	Java Sort	Solution
Data Structures	Easy	010	Java Subarray	Solution
Data Structures	Easy	015	Java Generics	Solution
Data Structures	Easy	015	Java List	Solution
Data Structures	Easy	020	Java BitSet	Solution
Data Structures	Medium	010	Java Comparator	Solution
Data Structures	Medium	020	Java Dequeue	Solution
Data Structures	Medium	020	Java Priority Queue	Solution
Data Structures	Medium	020	Java Stack	Solution
Data Structures	Medium	025	Java 1D Array (Part 2)	Solution
Introduction	Easy	003	Welcome to Java!	Solution
Introduction	Easy	005	Java Stdin and Stdout I	Solution
Introduction	Easy	010	Java Datatypes	Solution
Introduction	Easy	010	Java End-of-file	Solution
Introduction	Easy	010	Java If-Else	Solution
Introduction	Easy	010	Java Int to String	Solution
Introduction	Easy	010	Java Loops II	Solution
Introduction	Easy	010	Java Loops I	Solution
Introduction	Easy	010	Java Output Formatting	Solution
Introduction	Easy	010	Java Static Initializer Block	Solution
Introduction	Easy	010	Java Stdin and Stdout II	Solution
Introduction	Easy	015	Java Currency Formatter	Solution
Introduction	Easy	015	Java Date and Time	Solution
Object Oriented Programming	Easy	005	Java Inheritance I	Solution
Object Oriented Programming	Easy	010	Java Abstract Class	Solution
Object Oriented Programming	Easy	010	Java Inheritance II	Solution
Object Oriented Programming	Easy	010	Java Instanceof keyword	Solution
Object Oriented Programming	Easy	010	Java Interface	Solution
Object Oriented Programming	Easy	010	Java Method Overriding 2 (Super Keyword)	Solution
Object Oriented Programming	Easy	010	Java Method Overriding	Solution
Object Oriented Programming	Easy	015	Java Iterator	Solution
Strings	Easy	005	Java Strings Introduction	Solution
Strings	Easy	005	Java Substring	Solution
Strings	Easy	010	Java Anagrams	Solution
Strings	Easy	010	Java String Reverse	Solution
Strings	Easy	010	Java Substring Comparisons	Solution
Strings	Easy	015	Java String Tokens	Solution
Strings	Easy	020	Pattern Syntax Checker	Solution
Strings	Easy	020	Valid Username Regular Expression	Solution
Strings	Medium	020	Tag Content Extractor	Solution
Strings	Medium	025	Java Regex 2 - Duplicate Words	Solution
Strings	Medium	025	Java Regex	Solution

Algorithms

Subdomain	Difficulty	Points	Challenge	Solution
Game Theory	Medium	070	Chocolate in Box	Solution
Implementation	Easy	010	Apple and Orange	Solution
Implementation	Easy	010	Between Two Sets	Solution
Implementation	Easy	010	Bill Division	Solution
Implementation	Easy	010	Breaking the Records	Solution
Implementation	Easy	010	Divisible Sum Pairs	Solution
Implementation	Easy	010	Drawing Book	Solution
Implementation	Easy	010	Grading Students	Solution
Implementation	Easy	010	Migratory Birds	Solution
Implementation	Easy	010	Number Line Jumps	Solution
Implementation	Easy	010	Sales by Match	Solution
Implementation	Easy	010	Subarray Division	Solution
Implementation	Easy	015	Beautiful Days at the Movies	Solution
Implementation	Easy	015	Cats and a Mouse	Solution
Implementation	Easy	015	Counting Valleys	Solution
Implementation	Easy	015	Day of the Programmer	Solution
Implementation	Easy	015	Electronics Shop	Solution
Implementation	Easy	015	Jumping on the Clouds: Revisited	Solution
Implementation	Easy	015	Library Fine	Solution
Implementation	Easy	015	Save the Prisoner!	Solution
Implementation	Easy	015	The Hurdle Race	Solution
Implementation	Easy	015	Viral Advertising	Solution
Implementation	Easy	020	Angry Professor	Solution
Implementation	Easy	020	Append and Delete	Solution
Implementation	Easy	020	Beautiful Triplets	Solution
Implementation	Easy	020	Circular Array Rotation	Solution
Implementation	Easy	020	Designer PDF Viewer	Solution
Implementation	Easy	020	Equalize the Array	Solution
Implementation	Easy	020	Jumping on the Clouds	Solution
Implementation	Easy	020	Picking Numbers	Solution
Implementation	Easy	020	Repeated String	Solution
Implementation	Easy	020	Sequence Equation	Solution
Implementation	Easy	020	Service Lane	Solution
Implementation	Easy	020	Sherlock and Squares	Solution
Implementation	Easy	020	Utopian Tree	Solution
Implementation	Easy	025	ACM ICPC Team	Solution
Implementation	Easy	025	Chocolate Feast	Solution
Implementation	Easy	025	Cut the sticks	Solution
Implementation	Easy	025	Find Digits	Solution
Implementation	Easy	025	Taum and B'day	Solution
Implementation	Easy	030	Modified Kaprekar Numbers	Solution
Implementation	Medium	020	Climbing the Leaderboard	Solution
Implementation	Medium	020	Extra Long Factorials	Solution
Implementation	Medium	020	Forming a Magic Square	Solution
Implementation	Medium	020	Non-Divisible Subset	Solution
Implementation	Medium	025	The Time in Words	Solution
Implementation	Medium	030	3D Surface Area	Solution
Implementation	Medium	030	Encryption	Solution
Implementation	Medium	030	Organizing Containers of Balls	Solution
Implementation	Medium	030	Queen's Attack II	Solution
Implementation	Medium	030	The Grid Search	Solution
Implementation	Medium	035	Bigger is Greater	Solution
Implementation	Medium	040	Absolute Permutation	Solution
Implementation	Medium	040	Ema's Supercomputer	Solution
Implementation	Medium	040	Larry's Array	Solution
Implementation	Medium	040	The Bomberman Game	Solution
Implementation	Medium	050	Almost Sorted	Solution
Implementation	Hard	080	Matrix Layer Rotation	Solution
Implementation	Expert	100	Palindromic Border	Solution
Recursion	Medium	020	The Power Sum	Solution
Recursion	Medium	030	Crossword Puzzle	Solution
Recursion	Medium	030	Recursive Digit Sum	Solution
Recursion	Medium	040	Password Cracker	Solution
Recursion	Medium	050	Stone Division, Revisited	Solution
Recursion	Hard	040	Arithmetic Expressions	Solution
Recursion	Hard	050	K Factorization	Solution
Recursion	Hard	060	Bowling Pins	Solution
Search	Medium	050	Connected Cells in a Grid	Solution
Search	Medium	050	Pairs	Solution
Sorting	Medium	040	Fraudulent Activity Notifications	Solution
Sorting	Medium	040	Lily's Homework	Solution
Sorting	Medium	040	The Full Counting Sort	Solution
Strings	Easy	015	CamelCase	Solution
Strings	Medium	030	Highest Value Palindrome	Solution
Strings	Medium	035	Sherlock and the Valid String	Solution
Strings	Medium	050	Sherlock and Anagrams	Solution
Strings	Expert	036.36	Two Strings Game	Solution
Warmup	Easy	001	Solve Me First	Solution
Warmup	Easy	010	A Very Big Sum	Solution
Warmup	Easy	010	Birthday Cake Candles	Solution
Warmup	Easy	010	Compare the Triplets	Solution
Warmup	Easy	010	Diagonal Difference	Solution
Warmup	Easy	010	Mini-Max Sum	Solution
Warmup	Easy	010	Plus Minus	Solution
Warmup	Easy	010	Simple Array Sum	Solution
Warmup	Easy	010	Staircase	Solution
Warmup	Easy	015	Time Conversion	Solution

1 Week Preparation Kit

Exercises

Day	Difficulty	Challenge	Solution
Day 1	Easy	Mini-Max Sum	Solution
Day 1	Easy	Plus Minus	Solution
Day 1	Easy	Time Conversion	Solution
Day 2	Easy	Counting Sort 1	Solution
Day 2	Easy	Diagonal Difference	Solution
Day 2	Easy	Lonely Integer	Solution
Day 3	Easy	Caesar Cipher	Solution
Day 3	Easy	Tower Breakers	Solution
Day 3	Easy	Zig Zag Sequence	Solution
Day 4	Easy	Grid Challenge	Solution
Day 4	Easy	New Year Chaos	Solution
Day 4	Easy	Recursive Digit Sum	Solution
Day 5	Medium	Balanced Brackets	Solution
Day 5	Medium	Merge two sorted linked lists	Solution
Day 5	Medium	Queue using Two Stacks	Solution
Day 6	Medium	Simple Text Editor	Solution

Exams

Day	Difficulty	Challenge	Solution
Day 1	Easy	Find The Median	Solution
Day 2	Easy	Flipping The Matrix	Solution
Day 3	Easy	Palindrome Index	Solution
Day 4	Medium	Truck Tour	Solution
Day 5	Medium	Pairs	Solution

Important

Heavily inspired on RodneyShag's repo, go check his repo too!.