Problems

String

	#	LeetCode Link	Difficulty	Solution	Data Structures	Patterns / Approaches	B75	CTCI	EPI	TIQ	CCH
*	0005	Longest Palindromic Substring	Medium	Python	`String`	`DP`	✔️			✔️

Linked List

	#	LeetCode Link	Difficulty	Solution	Data Structures	Patterns / Approaches	B75	TIQ	CCH
	0002	Add Two Numbers	Medium	Python	`Linked List`	`Math` `Recursion`		✔️	✔️
*	0021	Merge Two Sorted Lists	Easy	Python	`Linked List`	`Recursion`	✔️
	0024	Swap Nodes in Pairs	Medium	Python	`Linked List`	`Recursion`			✔️
	0146	LRU Cache	Medium	Python	`Linked List`			✔️
*	0148	Sort List	Medium	Python	`Linked List`	`Divide and Conquer`		✔️

Stack

	#	LeetCode Link	Difficulty	Solution	Data Structures	Patterns / Approaches	B75	CTCI	EPI	TIQ	CCH
	0020	Valid Parentheses	Easy	Python	`String` `Stack`		✔️				✔️

Dynamic Programming

	#	LeetCode Link	Difficulty	Solution	Data Structures	Patterns / Approaches	B75	CTCI	EPI	TIQ	CCH
*	0072	Edit Distance	Hard	Python	`String`	`DP`

Two Pointers

	#	LeetCode Link	Difficulty	Solution	Data Structures	Patterns / Approaches	B75	CTCI	TIQ
	0011	Container With Most Water	Medium	Python	`Array`	`Two Pointers` `Greedy`	✔️
*	0015	3Sum	Medium	Python	`Array`	`Two Pointers` `Sorting`	✔️		✔️
	0016	3Sum Closest	Medium	Python	`Array`	`Two Pointers` `Sorting`			✔️
*	0019	Remove Nth Node From End of List	Medium	Python	`Linked List`	`Two Pointers`	✔️	✔️
	0026	Remove Duplicates from Sorted Array	Easy	Python	`Array`	`Two Pointers`			✔️

Sliding Window

	#	LeetCode Link	Difficulty	Solution	Data Structures	Patterns / Approaches	B75	CTCI	EPI	TIQ	CCH
*	0003	Longest Substring Without Repeating Characters	Medium	Python	`String` `Hash Table`	`Sliding Window`	✔️			✔️

Binary Search

	#	LeetCode Link	Difficulty	Solution	Data Structures	Patterns / Approaches	B75	TIQ	CCH
*	0033	Search in Rotated Sorted Array	Medium	Python	`Array`	`Binary Search`	✔️	✔️
	0034	Find First and Last Position of Element in Sorted Array	Medium	Python	`Array`	`Binary Search`
*	0035	Search Insert Position	Easy	Python	`Array`	`Binary Search`			✔️

Divide and Conquer

	#	LeetCode Link	Difficulty	Solution	Data Structures	Patterns / Approaches	B75	CTCI	EPI	TIQ	CCH
*	0023	Merge k Sorted Lists	Hard	Python	`Linked List`	`DC` `Merge Sort`	✔️

Backtracking

	#	LeetCode Link	Difficulty	Solution	Data Structures	Patterns / Approaches	B75	CTCI	EPI	TIQ	CCH
	0017	Letter Combinations of a Phone Number	Medium	Python	`String` `Hash Table`	`Backtracking`				✔️
	0046	Permutations	Medium	Python	`Array`	`Backtracking`

Misc

	#	LeetCode Link	Difficulty	Solution	Data Structures	Patterns / Approaches	B75	CTCI	TIQ	CCH
	0001	Two Sum	Easy	Python	`Array` `Hash Table`		✔️			✔️
	0009	Palindrome Number	Easy	Python		`Math`				✔️
	0013	Roman to Integer	Easy	Python	`String` `Hash Table`	`Math`				✔️
	0014	Longest Common Prefix	Easy	Python	`String`
	0022	Generate Parentheses	Medium						✔️
	0046	Permutations	Medium						✔️
	0048	Rotate Image	Medium	Python	`Array` `Matrix`	`Math`	✔️	✔️
	0049	Group Anagrams	Medium	Python	`Hash Table` `String`	`Sorting`	✔️		✔️
*	0053	Maximum Subarray	Easy	Python	`Array`	`DP` `DC`	✔️			✔️
	0054	Spiral Matrix	Medium	Python	`Array` `Matrix`	`Simulation`	✔️			✔️
*	0055	Jump Game	Medium	Python	`Array`	`DP` `Greedy`	✔️		✔️	✔️
	0056	Merge Intervals	Medium	Python	`Array`	`Sorting`	✔️		✔️
	0057	Insert Interval	Medium	Python	`Array`		✔️			✔️
	0062	Unique Paths	Medium	Python	`Array` `Matrix`	`Math` `DP` `Combinatorics`	✔️		✔️	✔️
	0063	Unique Paths II	Medium	Python	`Array` `Matrix`	`DP`				✔️
	0070	Climbing Stairs	Easy	Python		`Math` `DP` `Memorization`	✔️			✔️
	0073	Set Matrix Zeroes	Medium	Python	`Array` `Matrix`		✔️	✔️	✔️
	0075	Sort Colors	Medium						✔️
	0076	Minimum Window Substring	Hard		`Hash Table` `String`	`Sliding Window`	✔️
	0078	Subsets	Medium						✔️
*	0079	Word Search	Medium	Python	`Array` `Matrix`	`Backtracking`	✔️		✔️
	0083	Remove Duplicates from Sorted List	Easy	Python	`Linked List`	`Two Pointers`
*	0086	Partition List	Medium	Python	`Linked List`	`Two Pointers`		✔️
	0091	Decode Ways	Medium	Python	`String`	`DP`	✔️
	0094	Binary Tree Inorder Traversal	Easy						✔️
	0098	Validate Binary Search Tree	Medium	Python	`Binary Tree` `BST`	`DFS`	✔️			✔️
	0100	Same Tree	Easy	Python	`Binary Tree`	`DFS` `BFS`	✔️
	0101	Symmetric Tree	Easy	Python	`Binary Tree`	`DFS` `BFS`
	0102	Binary Tree Level Order Traversal	Medium	Python	`Binary Tree`	`BFS`	✔️
	0103	Binary Tree Zigzag Level Order Traversal	Medium						✔️
	0104	Maximum Depth of Binary Tree	Easy	Python	`Binary Tree`	`DFS` `BFS`	✔️			✔️
*	0105	Construct Binary Tree from Preorder and Inorder Traversal	Medium	Python	`Array` `Hash Table` `Binary Tree`	`DC`	✔️		✔️
	0108	Convert Sorted Array to Binary Search Tree	Easy	Python	`Array` `Binary Tree` `BST`	`DC`				✔️
*	0109	Convert Sorted List to Binary Search Tree	Medium	Python	`Linked List` `Binary Tree` `BST`	`DC`				✔️
	0110	Balanced Binary Tree	Easy	Python	`Binary Tree`	`DFS`				✔️
*	0111	Minimum Depth of Binary Tree	Easy	Python	`Binary Tree`	`DFS` `BFS`				✔️
	0116	Populating Next Right Pointers in Each Node	Medium						✔️
	0118	Pascal's Triangle	Easy	Python	`Array`	`DP`
	0121	Best Time to Buy and Sell Stock	Easy	Python	`Array`	`DP`	✔️
	0122	Best Time to Buy and Sell Stock II	Easy	Python	`Array`	`DP` `Greedy`			✔️
*	0124	Binary Tree Maximum Path Sum	Hard	Python	`Binary Tree`	`DP` `DFS`	✔️
	0125	Valid Palindrome	Easy	Python	`String`	`Two Pointers`	✔️
*	0128	Longest Consecutive Sequence	Medium	Python	`Array` `Hash Table`	`Union Find`	✔️
	0133	Clone Graph	Medium	Python	`Graph` `Hash Table`	`DFS` `BFS`	✔️			✔️
	0136	Single Number	Easy	Python	`Array`	`Bit Manipulation`				✔️
	0137	Single Number II	Medium							✔️
	0138	Copy List with Random Pointer	Medium	Python	`Linked List` `Hash Table`					✔️
	0139	Word Break	Medium	Python	`Hash Table` `String`	`DP` `Memorization`	✔️
	0141	Linked List Cycle	Easy	Python	`Linked List`	`Two Pointer`	✔️
*	0143	Reorder List	Medium	Python	`Linked List` `Stack`	`Two Pointer` `Recursion`	✔️
	0144	Binary Tree Preorder Traversal	Easy	Python	`Binary Tree`	`DFS`
	0145	Binary Tree Postorder Traversal	Easy	Python	`Binary Tree`	`DFS`
	0150	Evaluate Reverse Polish Notation	Medium	Python	`Array` `Stack`	`Math`				✔️
*	0152	Maximum Product Subarray	Medium	Python	`Array`	`DP`	✔️			✔️
	0154	Find Minimum in Rotated Sorted Array II	Hard							✔️
	0153	Find Minimum in Rotated Sorted Array	Medium	Python	`Array`	`Binary Search`	✔️			✔️
	0155	Min Stack	Medium	Python	`Stack`	`Design`				✔️
	0160	Intersection of Two Linked Lists	Easy						✔️
	0162	Find Peak Element	Medium						✔️
	0163	Missing Ranges (Premium)	Easy						✔️
*	0189	Rotate Array	Medium	Python	`Array`	`Math` `Two Pointers`			✔️
	0190	Reverse Bits	Easy	Python		`Bit Manipulation`	✔️
	0191	Number of 1 Bits	Easy	Python		`Bit Manipulation`	✔️			✔️
	0198	House Robber	Medium	Python	`Array`	`DP`	✔️
	0200	Number of Islands	Medium	Python	`Array` `Matrix`	`DFS` `BFS` `Union Find`	✔️		✔️
	0206	Reverse Linked List	Easy	Python	`Linked List`	`Recursion`	✔️
*	0207	Course Schedule	Medium	Python	`Graph`	`DFS` `BFS` `Topological Sort`	✔️
	0208	Implement Trie (Prefix Tree)	Medium	Python	`Trie` `Hash Table` `String`	`Design`	✔️
*	0211	Design Add and Search Words Data Structure	Medium	Python	`Trie` `String`	`DFS` `Design`	✔️
	0212	Word Search II	Hard				✔️
	0213	House Robber II	Medium	Python	`Array`	`DP`	✔️
	0215	Kth Largest Element in an Array	Medium						✔️
	0217	Contains Duplicate	Easy	Python	`Array` `Hash Table`	`Sorting`	✔️	✔️
	0226	Invert Binary Tree	Easy	Python	`Binary Tree`	`DFS` `BFS`	✔️
	0230	Kth Smallest Element in a BST	Medium	Python	`Binary Tree` `BST`	`DFS`	✔️		✔️
	0235	Lowest Common Ancestor of a Binary Search Tree	Easy	Python	`Binary Tree` `BST`	`DFS`	✔️
*	0238	Product of Array Except Self	Medium	Python	`Array`	`Prefix Sum`	✔️
	0240	Search a 2D Matrix II	Medium						✔️
	0242	Valid Anagram	Easy	Python	`Hash Table` `String`	`Sorting`	✔️
	0252	Meeting Rooms (Premium)	Easy				✔️
	0253	Meeting Rooms II (Premium)	Medium				✔️		✔️
	0261	Graph Valid Tree (Premium)	Medium				✔️
	0268	Missing Number	Easy	Python	`Array`	`Math` `Bit Manipulation`	✔️
	0269	Alien Dictionary (Premium)	Hard				✔️
	0271	Encode and Decode Strings (Premium)	Medium				✔️
	0283	Move Zeroes	Easy	Python	`Array`	`Two Pointers`			✔️
	0285	Inorder Successor in BST	Medium						✔️
	0295	Find Median from Data Stream	Hard				✔️
*	0297	Serialize and Deserialize Binary Tree	Hard	Python	`String` `Binary Tree`	`DFS` `BFS`	✔️
*	0300	Longest Increasing Subsequence	Medium	Python	`Array`	`Binary Search` `DP`	✔️		✔️
*	0322	Coin Change	Medium	Python	`Array`	`DP` `BFS`	✔️		✔️
	0323	Number of Connected Components in an Undirected Graph (Premium)	Medium				✔️
	0328	Odd Even Linked List	Medium						✔️
	0334	Increasing Triplet Subsequence	Medium						✔️
	0338	Counting Bits	Easy	Python		`DP` `Bit Manipulation`	✔️
	0347	Top K Frequent Elements	Medium				✔️		✔️
*	0371	Sum of Two Integers	Medium	Python		`Math` `Bit Manipulation`	✔️
	0377	Combination Sum IV	Medium	Python	`Array`	`DP`	✔️
*	0380	Insert Delete GetRandom O(1)	Medium	Python	`Array` `Hash Table`	`Design`
	0417	Pacific Atlantic Water Flow	Medium	Python	`Array` `Matrix`	`DFS` `BFS`	✔️
*	0424	Longest Repeating Character Replacement	Medium	Python	`String` `Hash Table`	`Sliding Window`	✔️
	0435	Non-overlapping Intervals	Medium	Python	`Array`	`DP` `Greedy` `Sorting`	✔️
	0495	Teemo Attacking	Easy	Python	`Array`
	0567	Permutation in String	Medium	Python	`String` `Hash Table`	`Two Pointers` `Sliding Window`		✔️
	0572	Subtree of Another Tree	Medium	Python	`Binary Tree`	`DFS` `Hash Function`	✔️
	0647	Palindromic Substrings	Medium	Python	`String`	`DP`	✔️
	0796	Rotate String	Easy	Python	`String`			✔️
*	1143	Longest Common Subsequence	Medium	Python	`String`	`DP`	✔️

* Didn't solve independently, or worth reviewing.

Patterns

Abbr	Pattern
DC	Divide and Conquer
DP	Dynamic Programming

Lists

Abbr	List
B75	Blind 75 LeetCode Questions
CTCI	Cracking the Coding Interview
EPI	Elements of Programming Interviews, EPI to LC
TIQ	Top Interview Questions, Top Interview Questions
CCH	Clean Code Handbook

Name		Name	Last commit message	Last commit date
Latest commit History 578 Commits
0001-0099		0001-0099
0100-0199		0100-0199
0200-0299		0200-0299
0300-0399		0300-0399
0400-0499		0400-0499
0500-0599		0500-0599
0600-0699		0600-0699
0700-0799		0700-0799
0800-0899		0800-0899
0900-0999		0900-0999
1000-1099		1000-1099
1100-1199		1100-1199
1200-1299		1200-1299
1400-1499		1400-1499
1500-1599		1500-1599
1600-1699/1650-lowest-common-ancestor-of-a-binary-tree-iii		1600-1699/1650-lowest-common-ancestor-of-a-binary-tree-iii
1700-1799		1700-1799
1800-1899/1877-minimize-maximum-pair-sum-in-array		1800-1899/1877-minimize-maximum-pair-sum-in-array
1900-1999/1909-remove-one-element-to-make-the-array-strictly-increasing		1900-1999/1909-remove-one-element-to-make-the-array-strictly-increasing
2100-2199		2100-2199
2200-2299		2200-2299
2500-2599		2500-2599
2600-2699/2627-debounce		2600-2699/2627-debounce
.gitignore		.gitignore
readme.md		readme.md

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