ds-algo-solutions

A collection of solutions for HackerRank data structures and algorithm problems in Python, JAVA, and CPP. This community-owned project aims to bring together the solutions for the DS & Algo problems across various platforms, along with the resources for learning them. Problems from Leetcode will be included soon in the project.

HackerRank

HackerRank is a place where programmers from all over the world come together to solve problems in a wide range of Computer Science domains such as algorithms, machine learning, or artificial intelligence, as well as to practice different programming paradigms like functional programming.

Topic	Question	Difficulty	CPP	JAVA	Python
Arrays
	2D Array	Easy		View
	Dynamic Array	Easy		View
	Left Rotation	Easy	View	View
	Sparse Arrays	Medium	View
	Array Manipulation	Hard	View
Linked Lists
	Print the Elements of a Linked List	Easy		View	View
	Insert a node at the head of a linked list	Easy	View
	Insert a Node at the Tail of a Linked List	Easy	View
	Insert a node at a specific position in a linked list	Easy	View
	Delete a Node	Easy	View
	Print in Reverse	Easy	View	View
	Compare two linked lists	Easy	View	View
	Merge two sorted linked lists	Easy	View	View
	Get Node Value	Easy	View
	Reverse a linked list	Easy			View
	Delete duplicate-value nodes from a sorted linked list	Easy			View
	Find Merge Point of Two Lists	Easy			View
	Cycle Detection	Easy
	Inserting a Node Into a Sorted Doubly Linked List	Easy
	Reverse a doubly linked list	Easy
Stacks
	Maximum Element	Medium
	Balanced Brackets	Medium
	Equal Stacks	Medium
	Largest Rectangle	Medium
	Simple Text Editor	Medium
	Waiter	Medium
Queues
	Queue using Two Stacks	Medium
	Castle on the Grid	Medium
	Down to Zero II	Medium
Trees
	Tree : Top View	Easy
	Tree: Preorder Traversal	Easy	View
	Tree: Inorder Traversal	Easy
	Tree: Postorder Traversal	Easy
	Tree: Level Order Traversal	Easy
	Tree: Height of a Binary Tree	Easy	View
	Binary Search Tree : Insertion	Easy
	Binary Search Tree : Lowest Common Ancestor	Easy
	Is This a Binary Search Tree?	Medium	View
	Swap Nodes [Algo]	Medium
	Tree: Huffman Decoding	Medium
Algorithms
	Grading Students	Easy
	Apple and Orange	Easy
	Number Line Jumps	Easy

Contribution Guidelines

Go to the HackerRank problem-solving section (https://www.hackerrank.com/domains/data-structures), solve a problem such that it passes all test cases, make a Pull Request with the solution in the respective folder. Feel free to suggest any useful resources for studying ds & algo.e

Also, please explain your code with comments.