Leetcode Core 220

Iterative problems:

1. Shuffle
2. HashMap
3. Pointers
4. LRU/LFU cache and Trie
5. Queue/Stack with tuple
6. Monotonic stack/queue
7. Level order/BFS/Topological sort
8. Kadane
9. Interval
10. Sliding window

Recursive problems:

1. Divide and conquor
2. Priority queue
3. Quick select/Merge sort
4. Union find
5. DFS/Check cycle
6. Recursion and memoization
7. All path(backtracking)

Short Core:

1. Binary Search
2. Quick Select
3. DP, Search, Backtracking
4. Graph(Add/Remove Vertex/Edge, DFS, BFS, hasCycle, shortestPath, topologicalSort)
5. LRU, LFU cache
6. Interval

Solutions of top 100 liked and top frequently asked interview questions.

Group	#	Category	#	Questions	R	I	Blind
A.Tabulation	1.1	Conbination DP	1	55. Jump Game	✓	✓	✓
Recursion/Memo			2	62. Unique Paths	✓	✓	✓
			3	64. Minimum Path Sum	✓	✓
			4	70. Climbing Stairs	✓	✓	✓
			5	91. Decode Ways	✓	✓	✓
			6	118. Pascal's Triangle	✓	✓
			7	139. Word Break	✓	✓	✓
			8	300. Longest Increasing Subsequence	✓	✓	✓
			9	322. Coin Change	✓	✓	✓
			10	416. Partition Equal Subset Sum	✓	✓
			11	494. Target Sum	✓	✓
			12	1143. Longest Common Subsequence	✓	✓	✓
	1.2	Local/Global DP	1	128. Longest Consecutive Sequence	✓	✓	✓
			2	134. Gas Station	✓	✓
			3	221. Maximal Square	✓	✓
			4	279. Perfect Squares	✓	✓
	1.3	Kadane DP	1	53. Maximum Subarray		✓	✓
			2	152. Maximum Product Subarray		✓	✓
	1.4	Decision Making DP	1	198. House Robber	✓	✓	✓
			2	213. House Robber II	✓	✓	✓
			3	121. Best Time to Buy and Sell Stock	✓	✓	✓
			4	309. Best Time to Buy and Sell Stock with Cooldown	✓	✓
	1.5	Two String Matching DP	1	5. Longest Palindromic Substring	✓	✓	✓
			2	10 Regular Expression Matching	✓	✓
			3	44. Wildcard Matching	✓	✓
			4	72. Edit Distance	✓	✓
			5	647. Palindromic Substrings	✓	✓	✓
	1.6	Two Direction DP	1	11. Container With Most Water	✓	✓	✓
			2	238. Product of Array Except Self	✓	✓	✓
	1.7	Merging Intervals DP	1	96. Unique Binary Search Trees	✓	✓
			2	312. Burst Balloons	✓	✓
	2.1	Overlapping Interval	1	56. Merge Interval		✓	✓
			2	57. Insert Interval		✓	✓
			3	252. Meeting Rooms		✓	✓
			4	253. Meeting Rooms II		✓	✓
	2.2	Max non-overlapping Interval	5	435. Non-overlapping Intervals		✓	✓
			6	452. Minimum Number of Arrows to Burst Balloons		✓
	2.3	Intersection 2 pointers	7	986. Interval List Intersections		✓
			8	1229. Meeting Scheduler		✓
	3	Binary Search	1	278. First Bad Version		✓
			2	69. Sqrt(x)	✓	✓
			3	35. Search Insert Position		✓
			4	981. Time Based Key-Value Store		✓
			5	1011. Capacity To Ship Packages Within D Days		✓
			6	410. Split Array Largest Sum		✓
			7	875. Koko Eating Bananas		✓
			8	1482. Minimum Number of Days to Make m Bouquets		✓
			9	668. Kth Smallest Number in Multiplication Table		✓
			10	719. Find K-th Smallest Pair Distance		✓
			11	1201. Ugly Number III		✓
			12	1283. Find the Smallest Divisor Given a Threshold		✓
			13	4. Median of Two Sorted Arrays	✓
			14	33. Search in Rotated Sorted Array		✓	✓
			15	34. Search for a Range (First and Last Position)		✓
			16	153. Minimum in Rotated Sorted Array	✓	✓	✓
			17	162. Find Peak Element	✓	✓
			18	287. Find the Duplicate Number	✓	✓
			19	300. Longest Increasing Subsequence		✓
			20	378. Kth Smallest Element in a Sorted Matrix		✓
	4.1	Sliding Window	1	3. Longest Substring Without Repeating Characters		✓	✓
			2	76. Minimum Window Substring		✓	✓
			3	340. Longest Substring with At Most K Distinct Characters		✓
			4	395. Longest Substring with At Least K Repeating Characters		✓
			5	424. Longest Repeating Character Replacement		✓	✓
			6	438. Find All anagrams in a String		✓
			7	763. Partition Labels		✓
	4.2	HashMap	1	1. Two Sum		✓	✓
			2	13. Roman to Integer		✓
			3	49. Group Anagrams		✓	✓
			4	138. Copy List with Random Pointer		✓
			5	169. Majority Element		✓
			6	217. Contains Duplicate		✓	✓
			7	242. Valid Anagram		✓	✓
			8	350. Intersection of Two Arrays II		✓
			9	380. Insert Delete GetRandom O(1)		✓
			10	387. First Unique Character in a String		✓
			11	454. 4Sum II		✓
			12	560. subarray Sum Equals K		✓
	4.3	Prefix Sum	1	308. Range Sum Query 2D - Mutable		✓
			2	560. Subarray Sum Equals K		✓
	5.1	Pointers	1	15. 3Sum		✓	✓
			2	26. Remove Duplicates from Sorted Array		✓
			3	48. Rotate Image		✓	✓
			4	54. Spiral Matrix		✓	✓
			5	66. Plus One		✓
			6	73. Set Matrix Zeros		✓	✓
			7	88. Merge Sorted Array		✓
			8	116. Populating Next Right Pointers in Each Node	✓	✓
			9	125. Valid Palindrome		✓	✓
			10	163. Missing Ranges		✓
			11	240. Search a 2D Matrix II	✓	✓
			12	251. Flatten 2D Vector		✓
			13	277. Find the Celebrity		✓
			14	283. Move Zeros		✓
			15	412. Fizz Buzz		✓
			16	581. Shortest Unsorted Continuous Subarray	✓	✓
			17	763. Partition Labels	✓	✓
	5.2	Negative Mark	1	448. Find All Numbers Disappeared in an Array		✓
	5.3	XOR	1	136. Single Number		✓
			2	268. Missing Number		✓	✓
	5.4	Bit Manipulation	1	190. Reverse Bits		✓	✓
			2	191. Number of 1 Bits		✓	✓
			3	289. Game of Life	✓
			4	338. Counting Bits		✓	✓
			5	371. Sum of Two Integers	✓		✓
B.Recursion	0	Recursion	1	172. Factorial Trailing Zeros	✓
	1	Backtracking	1	17. Letter Combinations of a Phone Number	✓
			2	39. Combination Sum	✓		✓
			3	46. Permutations	✓
			4	78. Subsets	✓
			5	131. Palindrome Partitioning	✓
Recursion/DFS	2.1	DFS	1	22. Generate Parentheses	✓
			2	94. Binary Tree Inorder Traversal	✓
			3	104. Maximum Depth of Binary Tree	✓		✓
	2.2	Postorder DFS	1	101. Symmetric Tree	✓
			2	124. Binary Tree Maximum Path Sum	✓		✓
			3	236. Lowest Common Ancestor of a Binary Tree	✓		✓
			4	543. Diameter of Binary Tree	✓
	2.3	Divide and Conquer DFS	1	23 Merge k Sorted Lists	✓		✓
			2	98. Validate Binary Search Tree	✓		✓
			3	105. Construct Binary Tree from Preorder and Inorder Traversal	✓		✓
			4	108. Convert Sorted Array to Binary Search Tree	✓
			5	148. Sort List	✓
			6	212. Word Search II	✓
			7	218. The Skyline Problem	✓
			8	230. Kth Smallest Element in BST	✓		✓
			9	285. Inorder Successor in BST	✓
			10	617. Merge Two Binary Trees	✓
	2.4	Divide and Conquer DFS with Memo	1	337. House Robber III	✓
			2	437. Path Sum III	✓
			3	572. Subtree of Another Tree	✓		✓
Recursion/Search	3.1	DFS and Checked	1	79. Word Search	✓		✓
			2	127. Word Ladder	✓
			3	130. Surrounded Regions	✓
			4	133. Clone Graph	✓		✓
			5	140. Word Break II	✓
			6	200. Number of Islands	✓		✓
			7	329. Longest Increasing Path in a Matrix	✓
			8	417. Pacific Atlantic Water Flow	✓		✓
	3.1.2	Union Find	1	130. Surrounded Regions	✓
			2	200. Number of Islands	✓
			3	261. Graph Valid Tree	✓		✓
	3.2	BFS and Checked	1	127. Word Ladder		✓
			2	130. Surrounded Regions		✓
	3.3	Trie Tree	1	208. Implement Trie		✓	✓
			2	211. Add and Search Word - Data structure design	✓	✓	✓
			3	212. Word Search II	✓		✓
	3.4	Matrix and Checked	1	36. Valid sudoku	✓	✓
			2	289. Game of Life	✓
			3	348. Design Tic-Tac-Toe		✓
Recursion/Graph	4.1	Graph, DFS and Check cycle	1	207. Course Schedule	✓		✓
			2	210. Course Schedule II	✓
			3	323. Number of Connected Components in an Undirected Graph	✓		✓
	4.2	Graph, BFS and Topological Sort	1	207. Course Schedule		✓	✓
			2	210. Course Schedule II		✓
			3	269. Alien Dictionary		✓	✓
	4.3	Bellman-Ford, Dijkstra	1	743. Network Delay Time		✓
C.Quick Select	1	Quick Select Partition	1	75. Sort Colors		✓
			2	215. Kth Largest Element in an Array	✓
			3	324. Wiggle Sort II	✓
	2.1	Quick Sort	✓
	2.2	Merge Sort	1	315. Count of Smaller Numbers After Self	✓
	2.3	Shuffle	1	215. Kth Largest Element in an Array	✓
			2	324. Wiggle Sort II	✓
			3	384. Shuffle an Array		✓
	2.4.1	Swap	1	41. First Missing Positive		✓
			2	344. Reverse String		✓
			3	380. Insert Delete GetRandom O(1)		✓
			4	448. Find All Numbers Disappeared in an Array		✓
	2.4.2	3 Way Reverse	1	189. Rotate Array		✓
D.Linked List	1	Linked List	1	2. Add Two Numbers	✓	✓
			2	19. Remove Nth Node From End of List	✓	✓	✓
			3	21. Merge Two Sorted Lists	✓	✓	✓
			4	141. Linked List Cycle	✓	✓	✓
			5	142. Linked List Cycle II		✓
			6	143. Reorder List	✓	✓	✓
			7	148. Sort List	✓	✓
			8	160. Intersection of Two Linked Lists	✓	✓
			9	206. Reverse Linked List	✓	✓	✓
			10	234. Palindrome Linked List	✓	✓
			11	237. Delete Node in a Linked List	✓	✓
			12	285. Inorder Successor in BST	✓	✓
			13	287. Find the Duplicate Number	✓	✓
			14	328. Odd Even Linked List	✓	✓
	2	Double Linked List	1	146. LRU Cache		✓
			2	460. LFU Cache		✓
E.BFS	1	BFS	1	45. Jump Game II	✓	✓
			2	226. Invert Binary Tree	✓	✓	✓
			3	297. Serialize and Deserialize Binary Tree	✓	✓	✓
	2.1	Queue	1	101. Symmetric Tree		✓
			2	102. Binary Tree Level Order Traversal		✓	✓
			3	103. Binary Tree Zigzag Level Order Traversal		✓
			4	116. Populating Next Right Pointers in Each Node		✓
	2.2	Monotonic Queue	1	239. Sliding Window Maximum		✓
	3.1	Stack	1	20. Valid Parentheses	✓	✓	✓
			2	32. Longest Valid Parentheses	✓	✓
			3	94. Binary Tree Inorder Traversal	✓	✓
			4	100. Same Tree	✓	✓	✓
			5	104. Maximum Depth of Binary Tree	✓	✓
			6	114. Flatten Binary Tree to Linked List	✓	✓
			7	150. Evaluate Reverse Polish Notation	✓	✓
			8	225. Implement Stack using Queues		✓
			9	232. Implement Queue using Stacks	✓
			10	155. Min Stack		✓
			11	227. Basic Valculator II	✓	✓
			12	230. Kth Smallest Element in BST	✓	✓
			13	236. Lowest Common Ancestor of a Binary Tree	✓	✓
			14	341. Flatten Nested List Iterator	✓	✓
			15	394. Decode String		✓
			16	739. Daily Temperatures	✓	✓
	3.2	Monotonic Stack	1	496. Next Greater Element I		✓
			2	503. Next Greater Element II		✓
			3	42. Trapping Rain Water	✓	✓
			4	84. Largest Rectangle Histogram		✓
			5	85. Maximal Rectangle		✓
F.Others	1	Math Division	1	7. Reverse Integer		✓
			2	8. String to Integer (atoi)		✓
			3	29. Divide Two Integers	✓	✓
			4	50. Pow(x, n)	✓
			5	166. Fraction to Recurring Decimal	✓	✓
			6	202. Happy Number	✓
			7	204. Count Primes		✓
	2	Substring	1	14. Longest Common Prefix	✓	✓
			2	28. Implement strStr()	✓	✓
			3	38. Count and Say	✓	✓
			4	271. Encode and Decode Strings	✓	✓	✓
	3	Greedy	1	122. Best Time to Buy and Sell Stock II		✓
			2	326. Power of Three		✓
			3	334. Increasing Triplet Subsequence		✓
	4	Point centered gcd	1	149. Max Points on a Line		✓
	5	Moore's Voting algorithm	1	169. Majority Element		✓
	6	ASCII	1	171. Excel Sheet Column Number		✓
			2	621. Task Scheduler		✓
	7	Sorting Variation	1	179. Largest Number		✓
			2	324. Wiggle Sort II		✓
			3	347. Top K Frequent Elements		✓	✓
			4	406. Queue Reconstruction by Height		✓
	8	Heap	1	215. Kth Largest Element in an Array		✓
			2	295. find Median from Data Stream		✓	✓
			3	743. Network Delay Time		✓
	9	Binary Search Tree	1	315. Count of Smaller Numbers After Self	✓
	10	Binary Indexed Tree	1	315. Count of Smaller Numbers After Self		✓