leetcode

Final 200 - Easy

Number	Problem Name	Solution
1	Valid Palindrome	Valid Palindrome
2	Two Sum	Two Sum
3	Missing Number	Missing Number
4	Linked List Cycle	Linked List Cycle
5	Valid Parentheses	Valid Parentheses
6	Merge Two Sorted Lists	Merge Two Sorted Lists
7	Middle of the Linked List	Middle of the Linked List
8	Palindrome Linked List	Palindrome Linked List
9	Reverse Linked List	Reverse Linked List
10	Climbing Stairs	Climbing Stairs
11	Symmetric Tree	Symmetric Tree
12	Invert Binary Tree	Invert Binary Tree
13	Maximum Depth of Binary Tree	Maximum Depth of Binary Tree
14	Same Tree	Same Tree
15	Summary Ranges	Summary Ranges
16	Valid Anagram	Valid Anagram
17	Ransom Note	Ransom Note
18	Isomorphic Strings	Isomorphic Strings
19	Contains Duplicate II	Contains Duplicate II
20	Happy Number	Happy Number
21	Remove Duplicates from Sorted Array	Remove Duplicates
22
23
24

Final 200 - Medium

Number	Problem Name	Solution
1	Find All Anagrams in a String	Find All Anagrams in a String
2	Group Anagrams	Group Anagrams
3	Count and Say	Count and Say
4	Subarray Sum Equals K	Subarray Sum Equals K
5	Longest Consecutive Sequence	Longest Consecutive Sequence
6	Container With Most Water	Container With Most Water
7	Maximum Product Subarray	Maximum Product Subarray
8	Product of Array Except Self	Product of Array Except Self
9	Longest Substring Without Repeating Characters	Longest Substring Without Repeating Characters
10	Evaluate Reverse Polish Notation	Evaluate Reverse Polish Notation
11	Min Stack	Min Stack
12	Simplify Path	Simplify Path
13	Add Two Numbers	Add Two Numbers
14	Copy List with Random Pointer	Copy List with Random Pointer
15	Odd Even Linked List	Odd Even Linked List
16	Remove Nth Node From End of List	Remove Nth Node From End of List
17	LRU Cache	LRU Cache
18	Validate Binary Search Tree	Validate Binary Search Tree
19	Binary Tree Level Order Traversal	Binary Tree Level Order Traversal
20	Implement Trie (Prefix Tree)	Implement Trie (Prefix Tree)
21	Design Add and Search Words Data Structure	Design Add and Search Words Data Structure
22	Replace Words)	Replace Words
23	Longest Word in Dictionary)	Longest Word in Dictionary
24	Coin Change	Coin Change
25	House Robber	House Robber
26	Word Break	Word Break
27	Minimum Size Subarray Sum	Minimum Size Subarray Sum
28	Maximum Subarray	Maximum Subarray
29	Sort Colors	Sort Colors
30	Kth Largest Element in an Array	Kth Largest Element in an Array
31	Find K Closest Elements	Find K Closest Elements
32	Find All Duplicates in an Array	Find All Duplicates in an Array
33	Top K Frequent Elements	Top K Frequent Elements
34	Find Peak Element	Find Peak Element
35	Minimum Number of Arrows to Burst Balloons	Minimum Number of Arrows to Burst Balloons
36	Merge Intervals	Merge Intervals
37	Insert Interval	Insert Interval
38	Remove Duplicates from Sorted Array II	Remove Duplicates II
39	Find Duplicate Number	Find Duplicate Number
40	Jump Game	Jump Game
41	Jump Game II	Jump Game II
42	Gas Station	Gas Station
43
44
45

Final 200 - Hard

Number	Problem Name	Solution
1	Basic Calculator	Basic Calculator
2	Trapping Rain Water	Trapping Rain Water
3	Word Search II	Word Search II
4	Median of Two Sorted Arrays	Median of Two Sorted Arrays
5	Reverse Nodes in k-Group	Reverse Nodes in k-Group
6
7
8
9
10

List of Topic-wise Leetcode Problems:

➤ Array Manipulation & Sorting

1.	Sort Colors ✅
2.	Find All Duplicates in an Array ✅
3.	Missing Number ✅
4.	Find Duplicate Number ✅
5.	Remove Duplicates from Sorted Array ✅
6.	Remove Duplicates from Sorted Array II ✅
7.	Find K Closest Elements ✅
8.	Find Missing Positive Integer
9.	Find Peak Element ✅
10.	Find the Maximum Sum Subarray (Kadane’s Algorithm) ✅
11.	Kth Largest Element in an Array ✅
12.	Top K Frequent Elements ✅
13.	Longest Consecutive Sequence ✅
14.	Find the Smallest Range Covering Elements from K Lists
15.	Heapsort
16. Maximum Gap
17. Wiggle Sort II

➤ Searching Algorithms (Binary Search & Variants)

1.	Search in Rotated Sorted Array
2.	Search in Rotated Sorted Array II
3.	Find First and Last Position in a Sorted Array
4.	Search Insert Position
5.	Find Minimum in Rotated Sorted Array
6.	Median of Two Sorted Arrays ✅
7.	Search a 2D Matrix

➤ Sliding Window & Substring Problems

1.	Valid Palindrome ✅
2.	Longest Substring Without Repeating Characters ✅
3.	Find All Anagrams in a String ✅
4.	Longest Palindromic Substring
5.	Minimum Window Substring

➤ Intervals & Merging Problems

1.	Summary Ranges ✅
2.	Merge Intervals ✅
3.	Insert Interval ✅
4.	Minimum Absolute Difference
5.	Minimum Number of Arrows to Burst Balloons ✅
6.	Maximum Number of Events That Can Be Attended
7.	Intersection of Two Arrays II

➤ Matrix Problems

1.	Rotate Image
2.	Set Matrix Zeroes
3.	Spiral Matrix
4.	Word Search

➤ Array/String Misc

1.	
2.	
3.	Find All Anagrams in a String ✅
4.	Subarray Sum Equals K ✅
5.	Minimum Size Subarray Sum ✅
6.	Maximum Product Subarray ✅
7.  Find First and Last Position in a Sorted Array
8.  Count and Say ✅

➤ Hashmaps

1. Valid Anagram ✅
2. Ransom Note ✅
3. Group Anagrams ✅
4. Isomorphic Strings ✅
5. Two Sum ✅
6. Contains Duplicate II ✅
7. Happy Number ✅
8. 

➤ Stacks and Queues

1.	Valid Parentheses ✅
2.	Min Stack ✅
3.	Backspace String Compare
4.	Simplify Path ✅
5.	Evaluate Reverse Polish Notation ✅
6.	Daily Temperatures
7.	Decode String
8.	Basic Calculator ✅
9.	Car Fleet
10.	Generate Parentheses
11.	Asteroid Collision
12.	Basic Calculator II
13.	Maximum Frequency Stack
14.	Longest Valid Parentheses
15.	Largest Rectangle in Histogram

➤ Linked Lists

1.	Reverse Linked List ✅
2.	Merge Two Sorted Lists ✅
3.	Linked List Cycle ✅
4.	Middle of the Linked List ✅
5.	Palindrome Linked List ✅
6.	Remove Nth Node From End of List ✅
7.	Copy List with Random Pointer ✅
8.	Add Two Numbers ✅
9.	Reorder List ✅
10.	Swap Nodes in Pairs ✅
11.	Odd Even Linked List ✅
12.	Sort List ✅
13.	Reverse Nodes in k-Group ✅
14.	Merge K Sorted Lists ✅
15.	LRU Cache ✅

➤ Trees

1.	Invert Binary Tree ✅
2.	Same Tree ✅
3.	Symmetric Tree ✅
4.	Maximum Depth of Binary Tree
5.	Balanced Binary Tree
6.	Subtree of Another Tree
7.	Lowest Common Ancestor of a Binary Search Tree
8.	Diameter of Binary Tree
9.	Path Sum
10.	Count Complete Tree Nodes
11.	Validate Binary Search Tree ✅
12.	Kth Smallest Element in a BST
13.	Construct Binary Tree from Preorder and Inorder Traversal
14.	Binary Tree Level Order Traversal ✅
15.	Binary Tree Zigzag Level Order Traversal
16.	Binary Tree Right Side View
17.	Count Good Nodes in Binary Tree
18.	Flatten Binary Tree to Linked List
19.	Path Sum II
20.	Populating Next Right Pointers in Each Node II
21.	Sum Root to Leaf Numbers
22.	Minimum Absolute Difference in BST
23.	Binary Tree Maximum Path Sum
24.	Serialize and Deserialize Binary Tree
25.	Recover Binary Search Tree

➤ Trie

1.	Implement Trie ✅
2.	Design Add and Search Words Data Structure ✅ 
3.	Longest Word in Dictionary ✅ 
4.	Replace Words ✅ 
5.  Word Search II ✅ 

➤ Heap

1.	Kth Largest Element in a Stream
2.	Last Stone Weight
3.	Kth Largest Element in an Array ✅
4.	K Closest Points to Origin
5.	Task Scheduler
6.	Top K Frequent Words
7.	Find K Closest Elements ✅
8.	Merge K Sorted Lists
9.	Find Median from Data Stream
10.	Sliding Window Median

➤ Backtracking

1.	N-Queens
2.	Sudoku Solver
3.	Word Search
4.	Subsets
5.	Permutations
6.	Combination Sum
7.	Generate Parentheses
8.	Palindrome Partitioning
9.	Letter Combinations of a Phone Number
10.	Restore IP Addresses

➤ Graphs

1.	Flood Fill
2.	Number of Islands
3.	Max Area of Island
4.	Clone Graph
5.	Course Schedule
6.	Course Schedule II
7.	Pacific Atlantic Water Flow
8.	Rotting Oranges
9.	Surrounded Regions
10.	Walls and Gates
11.	Graph Valid Tree
12.	Number of Connected Components in an Undirected Graph
13.	Redundant Connection
14.	Find Eventual Safe States
15.	Network Delay Time
16.	Path with Maximum Probability
17.	Word Ladder
18.	Shortest Path in a Grid with Obstacles Elimination
19.	Alien Dictionary
20.	Find Strongly Connected Components

➤ Dynamic Programming

1.	Climbing Stairs ✅
2.	Coin Change ✅
3.	Word Break ✅
4.	House Robber ✅
5.	Edit Distance
6.	Palindromic Substrings
7.	0/1 Knapsack Problem
8.	Longest Common Subsequence
9.	Longest Increasing Subsequence
10.	Partition Equal Subset Sum
11.	Decode Ways
12.	Unique Paths
13.	Maximal Square
14.	Shortest Common Supersequence
15.	Interleaving String
16. House Robber II
17. 

➤ Greedy Algorithms

1.	Activity Selection Problem
2.	Huffman Encoding
3.	Minimum Platforms
4.	Job Sequencing Problem
5.	Jump Game 
6.	Gas Station ✅
7.	Partition Labels
8.	Dijkstra’s Algorithm
9.	Trapping Rain Water ✅
10.	Largest Rectangle in Histogram
11.	Container With Most Water ✅
12.	Reorganize String

➤ Bit Manipulation, Maths, Misc

1.	Single Number
2.	Number of 1 Bits
3.	Counting Bits
4.	Reverse Bits
5.	Add Binary
6.	Divide Two Integers
7.	
8.	Single Number II
9.	Bitwise AND of Numbers Range
10.	Palindrome Number
11.	Plus One
12.	Pow(x, n)
13.	
14.	Factorial Trailing Zeroes
15.	Multiply Strings