Java-Hackerrank-Solutions 30 Days Of Code Day Difficulty Score Challenge Solution Day 0 Easy 30 Hello world Day00.java Day 1 Easy 30 DataTypes Day01.java Day 2 Easy 30 Operators Day02.java Day 3 Easy 30 Intro to Conditional Statements Day03.java Day 4 Easy 30 Class Vs. Instance Day04.java Day 5 Easy 30 Loops Day05.java Day 6 Easy 30 Lets Review Day06.java Day 7 Easy 30 Arrays Day07.java Day 8 Easy 30 Dictionaries and Maps Day08.java Day 9 Easy 30 Recursion3 Day09.java Day 10 Easy 30 Binary Numbers Day10.java Day 11 Easy 30 2d Arrays Day11.java Day 12 Easy 30 Inheritance Day12.java Day 13 Easy 30 Abstract Classes Day13.java Day 14 Easy 30 Scope Day14.java Day 15 Easy 30 Linked lists Day15.java Day 16 Easy 30 Exceptions-String to Integer Day16.java Day 17 Easy 30 More Exceptions Day17.java Day 18 Easy 30 Queues and Stacks Day18.java Day 19 Easy 30 Interfaces Day19.java Day 20 Easy 30 Sorting Day20.java Day 21 Easy 30 Generics Day21.java Day 22 Easy 30 Binary Search Trees Day22.java Day 23 Easy 30 BST Level-order traversal Day23.java Day 24 Easy 30 More Linked Lists Day24.java Day 25 Medium 30 Running Time and Complexity Day25.java Day 26 Easy 30 Nested Logic Day26.java Day 27 Easy 30 Testing Day27.java Day 28 Medium 30 RegEx, Patterns and Intro to Databases Day28.java Day 29 Medium 30 Bitwise AND Day29.java JAVA Subdomain Difficulty Challenge Solution Introduction Easy Welcome to Java! Welcome-to-java.java Introduction Easy Java Stdin and Stdout I Stdin-Stdout-1.java Introduction Easy Java If-Else If-else.java Introduction Easy Java Stdin and Stdout II Stdin-Stdout-2.java Introduction Easy Java Output Formatting Java-output-formatting.java Introduction Easy Java Loops 1 Java-loops-1.java Introduction Easy Java Loops 2 Java-loops-2.java Introduction Easy Java Datatypes Java-datatypes.java Introduction Easy Java End of file Java-end-of-file.java Introduction Easy Java Static initializer Block Java-static-initializer-block.java Introduction Easy Java Int to string Java-int-to-string.java Introduction Easy Java Date and time Java-date-time.java Introduction Easy Java currency formatter Java-currency-formatter.java Strings Easy Java String Introduction Java-string-introduction.java Strings Easy Java Substring Java-substring.java Strings Easy Java Substring comparisons Java-Substring-comparisons.java Strings Easy Java String Reverse Java-Reverse.java Strings Easy Java Anagrams Java-Anagrams.java Strings Easy Java String Tokens Java-String_tokens.java Strings Easy Pattren Syntax Checker Pattern-Syntax-Checker.java Strings Medium Java Regex Java-Regex.java Strings Medium Java Regex 2 Duplicate words Java-Regex2_duplicate-words.java Strings Easy Valid Username Regular Expression Valid-Username.java Strings Medium Tag Content Extractor Tag-Content-Extractor.java Big Number Medium Java BigDecimal Java-Big-Decimal.java Big Number Easy Java Primality Test Java-primality-test.java Big Number Easy Java Big Integer Java-BigInteger.java Object Oriented Programming Easy Java Inheritance 1 Java-Inheritance1.java Object Oriented Programming Easy Java Inheritance 2 Java-Inheritance2.java Object Oriented Programming Easy Java Abstract Class Java-AbstractClass.java Object Oriented Programming Easy Java Interface Java-Interface.java Object Oriented Programming Easy Java Method Overriding Java-Method-Overriding.java Object Oriented Programming Easy Java Method Overriding (Super Keyword) Java-Method-Overriding-Super-keyword.java Object Oriented Programming Easy Java Instance Of Java-Instanceof.java Object Oriented Programming Easy Java Iterator Java-Iterator.java Exception Handling Easy Java Exception Handling (Try-Catch) Java-Exception-Handling-1.java Exception Handling Easy Java Exception Handling Java-Exception-Handling-2.java Data Structures Easy Java 1D Array Java-1D-Array.java Data Structures Easy Java 2D Array Java-2D-Array.java Data Structures Easy Java Sub Array Java-Sub-Array.java Data Structures Easy Java Array List Java-Array-List.java Data Structures Medium Java 1D Array (Part 2) Java-1D-Array-2.java Data Structures Easy Java List Java-List.java Data Structures Easy Java Map Java-Map.java Data Structures Easy Java Stack Java-Stack.java Data Structures Easy Java HashSet Java-HashSet.java Data Structures Easy Java Generics Java-Generics.java Advanced Easy Java Varargs - Simple Addition Java-Var-Args.java Advanced Easy Java Reflection - Attributes Java-Reflection.java Advanced Medium Java Can You Access? Java-Can-You-Access.java Advanced Medium Java Prime Checker Java-prime-checker.java Advanced Easy Java Factory Pattern Java-Factory-Pattern.java Advanced Easy Java Singleton Pattern Java-Singleton-Pattern.java Advanced Medium Java Visitor Pattern Java-Visitor-Pattern.java Advanced Medium Java Annotations Java-Annotations.java Advanced Easy Covariant Return Types Java-Covariance.java Advanced Medium Java Lambda Expressions Java-Lambda-Expressions.java Advanced Medium Java MD5 Java-MD5.java Advanced Medium Java SHA-256 Java-Annotations.java