Things to do:

• Things to Know in C++/Java/Python or any language. → User Input/Output. → Data Types → If Else statement → Switch Statement → Arrays , Strings → For Loop → While Loop → Function → Time Complexity
• Build-up Logical Thinking. → Practice Pattern Questions from any source like Leetcode.
• Learn STL/Java-Collections or similar thing in your language.
• Basic Maths. → Count Digits → Reverse a Number → Check Palindrome → GCD or HCF → Armstrong Number → Print all Divisors → Check for Prime
• Learn Basic Recursion. → Understand recursion by print something N times → Print name N times using recursion → Print 1 to N using recursion → Print N to 1 using recursion → Sum of first N numbers → Factorial of N numbers → Reverse an array → Check if a string is palindrome or not → Fibonacci Number
• Learn Basic Hashing. → Counting frequencies of array elements → Find the highest/lowest frequency element

Day 1 to 10: Sorting

Things to do:

• Selection Sort
• Bubble Sort
• Insertion Sort
• Merge Sort
• Quick Sort
• Cycle Sort
• Heap Sort

Day 11–25: Binary Search

Things to do:

• Binary Search on 1D Arrays

→ Binary Search to find X in Sorted Array → Lower Bound and Upper Bound → Search Insert Position → Check if Input array is sorted → Find the first and last occurrence of a given number in a sorted array → Count occurrence of a number in a sorted array with duplicates → Find peak element → Search in Rotated Sorted Array I → Search in Rotated Sorted Array II → Find minimum in Rotated Sorted Array → Single element in a sorted Array → Find kth element of two sorted arrays → Find out how many times has an array been rotated → Order-Agnostic Binary Search

• Binary Search on 2D Arrays → Search in a 2D matrix → Find Peak Element → Matrix Median
• Find Answers by Binary Search in Search Space → Find square root of a number in log n → Find Nth root of a number using BS → Koko Eating Bananas → Minimum days to make M bouquets → Find the smallest Divisor → Capacity to Ship Packages within D Days → Median of two sorted arrays → Aggressive Cows → Book Allocation Problem → Split array-Largest Sum → Kth Missing Positive number → Minimize Max Distance to Gas Station → Median of 2 sorted arrays → Kth element of 2 sorted arrays

Day 26–30: Strings

Things to do:

• Basic → Remove outermost Paranthesis → Reverse words in a given string/Palindrome Check → Largest odd number in a string → Longest Common Prefix → Isomorphic String → check whether one string is a rotation of another → Check if two strings are anagram of each other
• Medium String Problem → Sort Characters by frequency → Maximum Nesting Depth of Paranthesis → Roman Number to Integer and vice versa → Implement Atoi → Count Number of Substrings → Longest Palindromic Substring → Sum of Beauty of all substring → Reverse Every Word in A String

Day 31–41: LinkedList

Things to do:

• 1D LinkedList
• Doubly LinkedList
• Medium Level Problems of LL → Middle of a LinkedList → Reverse a LinkedList → Detect if linked list has a cycle in it → Find the starting point in LL → Length of Loop in LL → Check if LL is palindrome or not → Segregate odd and even nodes in LL → Remove Nth node from the back of the LL → Delete the middle node of LL → Sort LL → Sort a LL of 0's and 1's by changing links → Find the intersection point of Y LL → Add 1 to a number represented by LL → Add two numbers in LL
• Medium Level Problems of DLL →Delete all occurrences of a key in DLL → Find pairs with given sum in DLL → Remove duplicates from sorted DLL
• Hard Level Problems of LL → Reverse LL in group of given size K →Rotate a LL → Flattening of LL → Clone a LinkedList with random and next pointer

Day 42–62: Recursion

Things to do:

• Get a Strong Hold → Recursive Implementation of atoi() → Pow(x,n) → Count Good numbers → Sort a stack using recursion → Reverse a stack using recursion
• Subsequences Pattern → Generate all binary strings → Generate Paranthesis → Print all subsequences/Power Set → Learn All Patterns of Subsequences → Count all subsequences with sum K → Combination Sum → Combination Sum-II → Subset Sum-I → Subset Sum-II → Combination Sum — III → Letter Combinations of a Phone number
• Hard Level → Palindrome Partitioning → Word Search → N Queen → Rat in a Maze → Word Break → M Coloring Problem → Sudoku Solver → Expression Add Operators

Day 63–65: Bit Manipulation

Things to do:

• Basic → Introduction to Bit Manipulation → Check if the i-th bit is set or not → Check if a number is odd or not → Check if a number is power of 2 or not → Count the number of set bits → Set/Unset the rightmost unset bit → Swap two numbers → Divide two integers without using multiplication, division and mod operator
• Interview Problems → Count number of bits to be flipped to convert A to B → Find the number that appears odd number of times → Power Set → Find xor of numbers from L to R → Find the two numbers appearing odd number of times
• Advanced Maths → Print Prime Factors of a Number → All Divisors of a Number → Sieve of Eratosthenes → Find Prime Factorization of a Number using Sieve → Power(n, x)

Day 65–75: Stack and Queues

Things to do:

• Learning → Implement Stacks using Arrays → Implement Queue using Arrays → Implement Stack using Queue → Implement Queue using Stack → Implement stacks using Linkedlist → Implement Queue using Linkedlist → Check for balanced parenthesis → Implement Min Stack
• Prefix , Infix , Postfix Conversion Problems → Infix to postfix Conversion using stack → Prefix to Infix Conversion → Prefix to Postfix Conversion → Postfix to Prefix Conversion → Postfix to Infix → Convert Infix to Prefix Notation
• Monotonic Stack/Queue Problems ** → Next Greater Element → Next Greater Element 2 → Next Smaller Element → Number of NGEs to the right → Trapping Rainwater → Sum of subarray minimum → Stock span problem → Asteroid Collision → Sum of subarray ranges → Remove k Digits → Largest rectangle in a histogram → Maximal Rectangles
• Implementation Problems → Sliding Window maximum → Stock Span Problem → The Celebrity Problem → Rotten Oranges → LRU cache → LFU cache

Day 75–85: Greedy Algorithms

Things to do:

• Practice -link

Day 86–101: Binary Tree

Things to do:

• Basic → Basic tree structure → Traversing a Binary Tree (Preorder, Postorder , Inorder) → Balanced Binary Search Tree
• Problems → Find height or depth of a binary tree → Finding Diameter of a Tree using height of each node →Find number of Universal Value subtrees in a Binary Tree → Find if a given Binary Tree is a Sub-Tree of another Binary Tree → Finding nodes at distance K from a given node → Copy a binary tree where each node has a random pointer → Zigzag Traversal of Binary Tree → Check if Binary Tree is foldable → Threaded Binary Tree → Convert Binary Tree to Threaded Binary Tree → Sum of k smallest elements in Binary Search Tree

Day 102–111: Graphs

Things to do:

• BFS/DFS
• Shortest path Algo
• Minimum spanning tree
• Union-Find

Refer : link

Day 112–120: Dynamic Programming

Things to do:

• Basic → link
• Problems → Climbing Stairs → Best Time to Buy and Sell Stock → Maximum Subarray → House Robber
• Hard Problems → Link