Table of Contents

• Time Complexity
• Mathematics
• Bits Manipulation
• Recursion
• Arrays
• Searching
• Sorting
• Matrix
• Hashing
• String
• Linked List
• Stack
• Queue
• Tree
• Binary Search Tree
• Heap
• Graph
• Greedy
• Backtracking
• Dynamic Programming
• Trie

🟩 🟧 🟥

Mathematics

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1	Absolute value		Theory		🟩 Easy	abs()
	2	Celsius To Fahrenheit		Theory		🟩 Easy	Math
	3	Roots of Quadratic equation		Theory		🟩 Easy	Math
	4	Factorial Of Number				🟩 Easy	Math
	5	Count digits in a factorial				🟩 Easy	Factorial, Math
	6	Series GP				🟩 Easy	Basic Math
	7	Prime Number				🟩 Easy	Basic Math
	8	Exactly 3 Divisors		Theory		🟩 Easy	Basic Math
	9	Addition Under Modulo		Theory		🟩 Easy	Modulo
	10	Multiplication Under Modulo		Theory		🟩 Easy	Modulo
	11	Modular Multiplicative Inverse				🟩 Easy	Modulo
	12	Trailing zeroes in factorial				🟧 Medium	Logic
	13	Prime Factors				🟧 Medium	Prime

Bits Manipulation

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1	Find first set bit				🟩 Easy	Bits, Modulo
	2	Rightmost different bit				🟩 Easy	XOR, Modulo
	3	Check whether K-th bit is set or not				🟩 Easy	XOR, Modulo
	4	Count total set bits				🟧 Medium	RIght shift
	5	Bit Difference				🟩 Easy	Bits
	6	Number is sparse or not				🟩 Easy	Bits
	7	Longest Consecutive 1's				🟩 Easy	Bits
	8	Gray Code				🟩 Easy	Xor, Right Shift
	9	Gray to Binary equivalent				🟩 Easy	Xor, Right Shift
	10	Power of 2				🟩 Easy	AND
	11	Swap all odd and even bits				🟩 Easy	OR
	12	Maximum AND Value				🟧 Medium	AND

Recursion

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1	Print 1 to n without using loops				🟩 Easy	Recursion
	2	Sum Of Digits				🟩 Easy	Recursion
	3	Nth Fibonacci Number				🟩 Easy	Recursion
	4	Digital Root				🟧 Medium	Recursion
	5	Fibonacci Using Recursion				🟩 Easy	Recursion
	6	Tower Of Hanoi				🟧 Medium	Recursion
	7	Josephus problem				🟧 Medium	Recursion

Arrays

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1

Searching

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1

Sorting

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1

Matrix

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1	What is Multidimensional Arrays c++		Pdf	Video	🟩 Easy	Matrix, Array
	2	Sum of upper and lower triangles		Pdf	Solution	🟩 Easy	Matrix, Array
	3	Transpose of Matrix		Pdf	Solution	🟩 Easy	Matrix, Array
	4	Rotate by 90 degree		Pdf	Solution	🟩 Easy	Matrix, Array
	5	Multiply the matrices	c++	Pdf	Solution	🟩 Easy	Matrix, Array
	6	Spirally traversing a matrix	c++	Pdf	Solution	🟧 Medium	Matrix, Array
	7	Interchanging the rows of a Matrix	c++	Pdf	Solution	🟩 Easy	Matrix, Array
	8	Matrix Interchange			Practice	🟩 Easy	Matrix, Array
	9	Search in a row-column sorted Matrix	c++	Pdf	Solution	🟧 Medium	Matrix, Array
	10	Boolean Matrix	c++	Pdf	Solution	🟧 Medium	Matrix, Array

Hashing

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1	What is Hashing Data structure		Pdf	Theory	🟩 Easy	Hashing
	2	Code of Hashing in c++	c++	Pdf	Solution	🟩 Easy	Hashing
	3	Direct Access Table		Pdf	Theory	🟩 Easy	Hash
	4	What is Hash Function and collision		Pdf	Theory	🟩 Easy	Hash
	5	What is chaining in collision handling		Pdf	Theory	🟩 Easy	Hashing
	6	What is unordered_set	c++	Pdf	Theory	🟩 Easy	Hash
	7	What is unordered_map	c++	GFG	Theory	🟩 Easy	Hash
	8	Non Repeating Element	c++	Pdf	Solution	🟩 Easy	Hashing
	9	First Repeating Element	c++	Pdf	Solution	🟩 Easy	Hashing
	10	Union of two arrays			Practice	🟩 Easy	Hashing
	11	Intersection of Two Arrays	c++	Pdf	Solution	🟩 Easy	unordered_set
	12	Key Pair	c++	Pdf	Solution	🟩 Easy	unordered_map
	13	Subarray with sum 0	c++	Pdf	Solution	🟧 Medium	unordered_set
	14	Winner of an election	c++	Pdf	Solution	🟩 Easy	unordered_map
	15	Pairs with Positive Negative values	c++	Pdf	Solution	🟩 Easy	map, Vector
	16	Print Anagrams Together / Group Anagrams	c++	Pdf	Solution	🟧 Medium	unordered_map, string
	17	Relative Sort Array / Sort an array according to the other	c++	Pdf	Solution	🟧 Medium	Map
	18	Custom Sort String	c++	Pdf	Solution	🟧 Medium	map
	19	Sort Array by Increasing Frequency	c++	Pdf	Solution	🟩 Easy	map, Lambda
	20	Longest Consecutive Sequence			Practice	🟧 Medium	map

String

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1	Naive Pattern Search			Important	🟩 Easy	Pattern
	2	Implement strStr()	c++	pdf		🟩 Easy	Pattern
	3	Binary String				🟩 Easy	string
	4	Anagram				🟩 Easy	string
	5	Check if string is rotated by two places				🟩 Easy	string
	6	Check if strings are rotations of each other or not				🟩 Easy	string
	7	Isomorphic Strings				🟩 Easy	string
	8	Check if a string is Isogram or not				🟩 Easy	string
	9	Keypad typing				🟩 Easy	string
	10	Repeated Character				🟩 Easy	string
	11	Non Repeating Character	c++		solution	🟧 Medium	string
	12	Maximum Occuring Character				🟩 Easy	string
	13	Remove common characters and concatenate				🟩 Easy	string
	14	Reverse words in a given string				🟩 Easy	string
	15	Sum of numbers in string	c++	pdf	solution	🟧 Medium	string
	16	Pangram Checking				🟩 Easy	string
	17	Minimum indexed character				🟩 Easy	string
	18	Smallest window in a string containing all the characters of another string				🟧 Medium	string
	19	Nth number made of prime digits				🟩 Easy	Prime, string

Linked List

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1	Introduction to Linked list Playlist c++			Theory	🟩 Easy	Linked List
	2	Data structures Competitive Programming			Theory	🟩 Easy	DSA
	3	Arrays in Data Structures			Theory	🟩 Easy	Arrays
	4	Pointers in C++ with code Practice			Theory	🟩 Easy	Pointers
	5	Struct in c++			Theory	🟩 Easy	Struct

Stack

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1	What is stack		GFG Link	Solution	🟩 Easy	Stack, Array
	2	Implement stack using array				🟩 Easy	Stack, Array
	3	Implement Stack using Linked List				🟩 Easy	Stack, Linked List
	4	Implement Stack using Linked List				🟩 Easy	Stack, Linked List
	5	Remove All Adjacent Duplicates In String				🟩 Easy	Stack, string
	6	Remove All Adjacent Duplicates in String II				🟧 Medium	Stack, string
	7	Valid Parentheses				🟩 Easy	Stack, string
	8	Implement two stacks in an array				🟩 Easy	Stack, Array
	9	Valid Parentheses				🟩 Easy	Stack, string
	10	Get min at pop				🟩 Easy	Stack, Array
	11	Min Stack				🟩 Easy	Stack, Array
	12	Delete middle element of a stack				🟩 Easy	Stack, STL
	13	Infix to Postfix				🟩 Easy	Stack
	14	Evaluate Reverse Polish Notation				🟧 Medium	Stack, Evaluation of Postfix Expression
	15	Online Stock Span				🟧 Medium	Stack, Stock span problem
	16	Next Greater Element II				🟧 Medium	Stack, Array
	17	Largest Rectangle in Histogram				🟥 Hard	Stack, Array
	18	The Celebrity Problem				🟧 Medium	Stack, Array

Queue

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1	What is Queue		GFG Link	Solution	🟩 Easy	Queue, STL
	2	Implement Queue using array				🟩 Easy	Queue, Array
	3	Implement Queue using Linked List		Scaler Topics Link		🟩 Easy	Queue, Linked List
	4	Queue Reversal				🟩 Easy	Queue, Stack
	5	Queue using two Stacks				🟩 Easy	Queue, Stack
	6	Implement Queue using Stacks				🟩 Easy	Stack, Queue
	7	Stack using two queues				🟩 Easy	Stack, Queue
	8	Generate Binary Numbers				🟩 Easy	Queue
	9	Reverse First K elements of Queue				🟩 Easy	Queue, Stack
	10	Circular tour				🟧 Medium	Queue, Sliding window

Tree

Status	#	Question	Code	Document	Video	Difficulty	Tag
	1	What is Tree		pdf	Solution1, solution2	🟩 Easy	Tree, Theory
	2	What is Binary tree		pdf	solution	🟩 Easy	Tree, Binary Tree
	3	How to code binary tree	c++		Solution	🟩 Easy	Tree, Code
	4	Properties of Binary tree		pdf	solution	🟩 Easy	Tree, Node
	5	Types of Binary tree		pdf	solution	🟩 Easy	Binary Tree
	6	Tree Traversal		pdf	solution1, solution2	🟩 Easy	Traversal, Inorder
	7	Code of Inorder Traversal	c++	pdf	solution	🟩 Easy	Inorder Traversal
	8	Code of Preorder and Postorder	c++		Solution	🟩 Easy	Preorder, Postorder
	9	Binary Tree Inorder Traversal	c++		Solution	🟩 Easy	Recursion, Tree
	10	Binary Tree Preorder Traversal			Practice	🟩 Easy	Recursion, Tree
	11	Binary Tree Postorder Traversal			Practice	🟩 Easy	Recursion, Tree
	12	Same Tree	c++		Solution	🟩 Easy	Tree Traversal
	13	Maximum Depth of Binary Tree	c++		Solution	🟧 Medium	Recursion, Tree
	14	Children Sum Parent	c++		Solution	🟩 Easy	Recursion, Tree
	15	Binary Tree Level Order Traversal	c++		Solution	🟧 Medium	Queue, Tree
	16	Level order traversal Line by Line			Practice	🟩 Easy	stack, Tree
	17	Binary Tree Zigzag Level Order Traversal	c++		Solution	🟧 Medium	Queue, Tree
	18	Maximum Width of Tree				🟩 Easy	Tree
	19	Balanced Binary Tree	c++		Solution	🟩 Easy	Tree
	20	Left View of Binary Tree				🟩 Easy	Tree
	21	Right View of Binary Tree				🟩 Easy	Tree
	22	Lowest Common Ancestor in a Binary Tree				🟧 Medium	Tree
	23	Diameter of Binary Tree				🟩 Easy	Tree
	24	Vertical Width of a Binary Tree				🟩 Easy	Tree
	25	Mirror Tree				🟩 Easy	Tree
	26	Check if subtree				🟧 Medium	Tree
	27	Make Binary Tree From Linked List				🟧 Medium	Tree

Binary Search Tree

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1	Inorder traversal of a BST				🟩 Easy	BST, Tree
	2	Search in a Binary Search Tree				🟩 Easy	BST, Tree
	2	Insert in a Binary Search Tree					BST, Tree

Heap

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1	Heap sort			Solution	🟩 Easy	Heap Basic
	2	Kth Largest Element in an Array			Solution	🟩 Easy	Heap Basic
	3	Kth Largest Element in a Stream			Solution	🟩 Easy	Heap Basic
	4	Top K Frequent Elements			Solution	🟩 Easy	Heap Basic
	5	Minimum Cost of ropes			Solution	🟩 Easy	Heap Basic
	6	Find K Closest Elements			Solution	🟧 Medium	Heap Medium
	7	Merge k Sorted Arrays			Solution	🟧 Medium	Heap Medium
	8	Find median in a stream			Solution	🟥 Hard	Heap Hard

Graph

Status	#	Title	Code	Document	Video	Difficulty	Tag
	1	Graph Introduction			Solution	🟩 Easy	Graph Theory
	2	Adjacency Matrix in graph			Solution	🟩 Easy	Graph Basic
	3	Adjacency List in graph			Solution	🟩 Easy	Graph
	4	How to code graph			Solution	🟩 Easy	Graph
	5	BFS Of Graph			Solution	🟩 Easy	Graph Theory
	6	Find If Path Exists in Graph	C++		Solution	🟩 Easy	Graph BFS
	7	Find the Town Judge	C++		Solution	🟩 Easy	Graph BFS
	8	DFS Of Graph			Solution	🟩 Easy	Graph Theory
	9	Number of Islands	C++		Solution	🟧 Medium	Graph DFS
	10	Flood Fill	C++		Solution	🟩 Easy	Graph Theory
	11	Detect cycle in undirected graph			Solution	🟩 Easy	Graph
	12	Topological sort (Kahn's BFS)	C++	Pdf	Solution	🟩 Easy	Graph
	13	Topological sort using DFS	C++	Pdf	Solution	🟧 Medium	Graph DFS
	14	Detect Cycle in a Directed Graph	C++	Pdf	Solution	🟧 Medium	Graph GFG

Greedy

Status	#	Title	Code	Document	Video	Difficulty	Tag
1

Backtracking

Status	#	Title	Code	Document	Video	Difficulty	Tag
1

Dynamic Programming

Status	#	Title	Code	Document	Video	Difficulty	Tag
1	Fibonacci Numbers - Top Down DP				🟩 Easy	Recursion

Trie

Status	#	Title	Code	Document	Video	Difficulty	Tag
1	Insert and Search				🟧 Medium	Trie