- Luck Balance (Greedy)
- Marc's Cakewalk (Greedy)
- Minimum absolute difference in an array (Greedy)
- Angry Professor (Implementation)
- Apple and Orange (Implementation)
- Beautiful days at the movies (Implementation)
- Beautiful Triplets (Implementation)
- Between Two Sets (Implementation)
- Birthday Chocolate (Implementation)
- Bon Appetit (Implementation)
- Breaking the records (Implementation)
- Cats and Mouse (Implementation)
- Cavity Map (Implementation)
- Circular Array Rotation (Implementation)
- Counting Valleys (Implementation)
- Cut the Sticks (Implementation)
- Day of the Programmer (Implementation)
- Designer PDF Viewer (Implementation)
- Divisible Sum Pair (Implementation)
- Drawing Book (Implementation)
- Electronics Shop (Implementation)
- Equalize the Array (Implementation)
- Fair Rations (Implementation)
- Find Digits (Implementation)
- Forming a Magic Square (Implementation)
- Grading Student (Implementation)
- Jumping on the Clouds (Implementation)
- Kangaroo (Implementation)
- Library Fine (Implementation)
- Lisa's Workbook (Implementation)
- Migratory Birds (Implementation)
- Minimum Distances (Implementation)
- Picking Numbers (Implementation)
- Repeated String (Implementation)
- Save the Prisoner (Implementation)
- Sequence Equation (Implementation)
- Service Lane (Implementation)
- Sherlock and Square (Implementation)
- Sock Merchant (Implementation)
- Taum and Birthday (Implementation)
- The Hurdle Race (Implementation)
- Utopian Tree (Implementation)
- Viral Advertising (Implementation)
- Correctness and the Loop Invariant (Sorting)
- Counting Sort I (Sorting)
- Insertion Sort Part I (Sorting)
- Insertion Sort Part II (Sorting)
- Intro to Tutorial Challenges (Sorting)
- Quicksort 1 - Partition (Sorting)
- Quicksort 2 - Sorting (Sorting)
- Running Time of Algorithm (Sorting)
- Alternating Characters (Strings)
- Anagram (Strings)
- Beautiful Binary String (Strings)
- Camel Case (Strings)
- Funny String (Strings)
- Game of Thrones I (Strings)
- Gemstones (Strings)
- Hackerrank in a String (Strings)
- Making Anagrams (Strings)
- Mars Exploration (Strings)
- Pangrams (Strings)
- Separate the Numbers (Strings)
- String Construction (Strings)
- Super Reduced String (Strings)
- The Love Letter Mystery (Strings)
- Two Strings (Strings)
- A very big Sum (Warm up)
- Birthday Cake Candle (Warm up)
- Compare the Triplets (Warm up)
- Diagonal Difference (Warm up)
- Min-Max Sum (Warm up)
- Plus Minus (Warm up)
- Simple Array Sum (Warm up)
- Solve Me First (Warm up)
- Staircase (Warm up)
- Time Conversion (Warm up)
- Full Counting Sort (Sorting)
- 2D Array (Arrays)
- Dynamic Array (Arrays)
- Left Rotation (Arrays)
- Delete a Node (Linked Lists)
- Print in Reverse (Linked Lists)
- Print the Elements (Linked Lists)
- Reverse a Linked List (Linked Lists)
- Equal Stacks (Stacks)
- Preorder Traversal (Trees)
- Reverse a Linked List (Linked Lists)
- Maximum Element (Stacks)
- Balanced Brackets (Stacks)
- Simple Text Editor (Stacks)
- Game of Two Stacks (Stacks)
- Arrays Left Rotation (Arrays)
- HashTables Ransom Notes (Dictionaries and HashMaps)
- Insert a Node at a Specific Position in a Linked List (Linked List)
- Linked List Detect a Cycle (Linked List)
- Bubble Sort (Sorting)
- Mark and Toys (Sorting)
- Strings Making Anagram (String Manipulation)
- Fraudulent Activity Notification (Sorting)
- Sorting Comparator (Sorting)
- Balanced Brackets (Stacks and Queues)
- Covariant (Advanced)
- Java Factory Pattern (Advanced)
- Java Reflection Attributes (Advanced)
- Java Single Pattern (Advanced)
- Java Varargs - Simple Addition (Advanced)
- Java Big Integer (Big Number)
- Java Primality Test (Big Number)
- Java 1D Array (Data Structures)
- Java 2D Array (Data Structures)
- Java Array List (Data Structures)
- Java Bit Set (Data Structures)
- Java Generics (Data Structures)
- Java HashSet (Data Structures)
- Java List (Data Structures)
- Java Map (Data Structures)
- Java Sort (Data Structures)
- Java SubArray (Data Structures)
- Java Exception Handling (Exception Handling)
- Java Exception Handling Try Catch (Exception Handling)
- Welcome to Java! (Introduction)
- Java Stdin and Stdout I (Introduction)
- Java If-Else (Introduction)
- Java Stdin and Stdout II (Introduction)
- Java Output Formatting (Introduction)
- Java Loops I (Introduction)
- Java Loops II (Introduction)
- Java Datatypes (Introduction)
- Java End-Of-file (Introduction)
- Java Static Initializer Block (Introduction)
- Java Int to String (Introduction)
- Java Date and TIme (Introduction)
- Java Currency Formatter (Introduction)
- Java Abstract Class (Object Oriented Programming)
- Java Inheritance I (Object Oriented Programming)
- Java Inheritance II (Object Oriented Programming)
- Java Instance of Keyword (Object Oriented Programming)
- Java Interface (Object Oriented Programming)
- Java Iterator (Object Oriented Programming)
- Java Method Overriding (Object Oriented Programming)
- Java Method Overriding 2 (Object Oriented Programming)\
- Java Strings Introduction (Strings)
- Java Substring (Strings)
- Java String Reverse (Strings)
- Java Anagrams (Strings)
- Java String Compare (Strings)
- Java String Tokens (Strings)
- Pattern Syntax Checker (Strings)
- Java Big Decimal (Big Number)
- Java Comparator (Data Structures)
- Duplicate Words (Strings)
- Java Regex (Strings)
- Java Regex 2 (Strings)
- Java Regex 3 (Strings)
- Java Content Extractor (Strings)
- Java 1D Array - Part 2 (Attempted) (Data Structures)
- Java Stack (Data Structures)
- Java MD5 (Advanced)
- Java SHA-256 (Advanced)
- Java Annotations (Advanced)
- Prime Checker (Advanced)
- Day 00: Hello World
- Day 01: Data Type
- Day 02: Operators
- Day 03: Intro to Conditional Statements
- Day 04: Class vs Instance
- Day 05: Loops
- Day 06: Let's Review
- Day 07: Arrays
- Day 08: Dictionaries and Maps
- Day 09: Recursion 3
- Day 10: Binary Numbers
- Day 11: 2D Arrays
- Day 12: Inheritance
- Day 13: Abstract Classes
- Day 14: Scope
- Day 15: Linked List
- Day 16: Exceptions - String to Integer
- Day 17: More Exceptions
- Day 18: Queues and Stacks
- Day 19: Interfaces
- Day 20: Sorting
- Day 21: Genarics
- Day 22: Binary Search Trees
- Day 23: BST Level-Order Traversal
- Day 24: More Linked Lists
- Day 26: Nested Logic
- Day 27: Testing
- Day 25: Running Time and Complexity
- Day 28: RegEx, Patterns and Intro to Database
- Day 29: Bitwise AND