LeetCode Practice List

ID	Title	Tags
1	Two Sum	Array, Hash Table
2	Add Two Numbers	Linked List, Math, Recursion
3	Longest Substring Without Repeating Characters	Hash Table, String, Sliding Window
4	Median of Two Sorted Arrays	Array, Binary Search, Divide and Conquer
5	Longest Palindromic Substring	Two Pointers, String, Dynamic Programming
6	Zigzag Conversion	String
7	Reverse Integer	Math
8	String to Integer (atoi)	String
9	Palindrome Number	Math
10	Regular Expression Matching	String, Dynamic Programming, Recursion
11	Container With Most Water	Array, Two Pointers, Greedy
12	Integer to Roman	Hash Table, Math, String
13	Roman to Integer	Hash Table, Math, String
14	Longest Common Prefix	Array, String, Trie
15	3Sum	Array, Two Pointers, Sorting
16	3Sum Closest	Array, Two Pointers, Sorting
17	Letter Combinations of a Phone Number	Hash Table, String, Backtracking
18	4Sum	Array, Two Pointers, Sorting
19	Remove Nth Node From End of List	Linked List, Two Pointers
20	Valid Parentheses	String, Stack
21	Merge Two Sorted Lists	Linked List, Recursion
22	Generate Parentheses	String, Dynamic Programming, Backtracking
23	Merge k Sorted Lists	Linked List, Divide and Conquer, Heap, Merge Sort
24	Swap Nodes in Pairs	Linked List, Recursion
25	Reverse Nodes in k-Group	Linked List, Recursion
26	Remove Duplicates from Sorted Array	Array, Two Pointers
27	Remove Element	Array, Two Pointers
28	Find the Index of the First Occurrence in a String	Two Pointers, String, String Matching
29	Divide Two Integers	Math, Bit Manipulation
30	Substring with Concatenation of All Words	Hash Table, String, Sliding Window
31	Next Permutation	Array, Two Pointers
32	Longest Valid Parentheses	String, Dynamic Programming, Stack
33	Search in Rotated Sorted Array	Array, Binary Search
34	Find First and Last Position of Element in Sorted Array	Array, Binary Search
35	Search Insert Position	Array, Binary Search
36	Valid Sudoku	Array, Hash Table, Matrix
37	Sudoku Solver	Array, Hash Table, Backtracking, Matrix
38	Count and Say	String
39	Combination Sum	Array, Backtracking
40	Combination Sum II	Array, Backtracking
41	First Missing Positive	Array, Hash Table
42	Trapping Rain Water	Array, Two Pointers, Dynamic Programming, Stack, Monotonic Stack
43	Multiply Strings	Math, String, Simulation
44	Wildcard Matching	String, Dynamic Programming, Greedy, Recursion
45	Jump Game II	Array, Dynamic Programming, Greedy
46	Permutations	Array, Backtracking
47	Permutations II	Array, Backtracking, Sorting
48	Rotate Image	Array, Math, Matrix
49	Group Anagrams	Array, Hash Table, String, Sorting
50	Pow(x, n)	Math, Recursion
51	N-Queens	Array, Backtracking
53	Maximum Subarray	Array, Divide and Conquer, Dynamic Programming
54	Spiral Matrix	Array, Matrix, Simulation
55	Jump Game	Array, Dynamic Programming, Greedy
56	Merge Intervals	Array, Sorting
57	Insert Interval	Array
62	Unique Paths	Math, Dynamic Programming, Combinatorics
68	Text Justification	Array, String, Simulation
70	Climbing Stairs	Math, Dynamic Programming, Memoization
72	Edit Distance	String, Dynamic Programming
73	Set Matrix Zeroes	Array, Hash Table, Matrix
75	Sort Colors	Array, Two Pointers, Sorting
78	Subsets	Array, Backtracking, Bit Manipulation
79	Word Search	Array, String, Backtracking, Depth-First Search, Matrix
84	Largest Rectangle in Histogram	Array, Stack, Monotonic Stack
85	Maximal Rectangle	Array, Dynamic Programming, Stack, Matrix, Monotonic Stack
86	Partition List	Linked List, Two Pointers
88	Merge Sorted Array	Array, Two Pointers, Sorting
91	Decode Ways	String, Dynamic Programming
92	Reverse Linked List II	Linked List
98	Validate Binary Search Tree	Tree, Depth-First Search, Binary Search Tree, Binary Tree
102	Binary Tree Level Order Traversal	Tree, Breadth-First Search, Binary Tree
103	Binary Tree Zigzag Level Order Traversal	Tree, Breadth-First Search, Binary Tree
104	Maximum Depth of Binary Tree	Tree, Depth-First Search, Breadth-First Search, Binary Tree
108	Convert Sorted Array to Binary Search Tree	Array, Divide and Conquer, Tree, Binary Search Tree, Binary Tree
112	Path Sum	Tree, Depth-First Search, Breadth-First Search, Binary Tree
113	Path Sum II	Backtracking, Tree, Depth-First Search, Binary Tree
121	Best Time to Buy and Sell Stock	Array, Dynamic Programming
122	Best Time to Buy and Sell Stock II	Array, Dynamic Programming, Greedy
123	Best Time to Buy and Sell Stock III	Array, Dynamic Programming
125	Valid Palindrome	Two Pointers, String
127	Word Ladder	Hash Table, String, Breadth-First Search
128	Longest Consecutive Sequence	Array, Hash Table, Union-Find
130	Surrounded Regions	Array, Depth-First Search, Breadth-First Search, Union-Find, Matrix
131	Palindrome Partitioning	String, Dynamic Programming, Backtracking
133	Clone Graph	Hash Table, Depth-First Search, Breadth-First Search, Graph Theory
134	Gas Station	Array, Greedy
139	Word Break	Array, Hash Table, String, Dynamic Programming, Trie, Memoization
141	Linked List Cycle	Hash Table, Linked List, Two Pointers
143	Reorder List	Linked List, Two Pointers, Stack, Recursion
146	LRU Cache	Hash Table, Linked List, Design, Doubly-Linked List
151	Reverse Words in a String	Two Pointers, String
155	Min Stack	Stack, Design
167	Two Sum II - Input Array Is Sorted	Array, Two Pointers, Binary Search
188	Best Time to Buy and Sell Stock IV	Array, Dynamic Programming
189	Rotate Array	Array, Math, Two Pointers
198	House Robber	Array, Dynamic Programming
199	Binary Tree Right Side View	Tree, Depth-First Search, Breadth-First Search, Binary Tree
200	Number of Islands	Array, Depth-First Search, Breadth-First Search, Union-Find, Matrix
203	Remove Linked List Elements	Linked List, Recursion
206	Reverse Linked List	Linked List, Recursion
207	Course Schedule	Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort
208	Implement Trie (Prefix Tree)	Hash Table, String, Design, Trie
210	Course Schedule II	Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort
215	Kth Largest Element in an Array	Array, Divide and Conquer, Sorting, Heap, Quickselect
216	Combination Sum III	Array, Backtracking
217	Contains Duplicate	Array, Hash Table, Sorting
219	Contains Duplicate II	Array, Hash Table, Sliding Window
220	Contains Duplicate III	Array, Sliding Window, Sorting, Bucket Sort, Ordered Set
221	Maximal Square	Array, Dynamic Programming, Matrix
224	Basic Calculator	Math, String, Stack, Recursion
227	Basic Calculator II	Math, String, Stack
232	Implement Queue using Stacks	Stack, Design, Queue
234	Palindrome Linked List	Linked List, Two Pointers, Stack, Recursion
237	Delete Node in a Linked List	Linked List
238	Product of Array Except Self	Array, Prefix Sum
252	Meeting Rooms	Array, Sorting
253	Meeting Rooms II	Array, Two Pointers, Greedy, Sorting, Heap, Prefix Sum
256	Paint House	Array, Dynamic Programming
261	Graph Valid Tree	Depth-First Search, Breadth-First Search, Union-Find, Graph Theory
265	Paint House II	Array, Dynamic Programming
273	Integer to English Words	Math, String, Recursion
277	Find the Celebrity	Two Pointers, Graph Theory, Interactive
283	Move Zeroes	Array, Two Pointers
284	Peeking Iterator	Array, Design, Iterator
295	Find Median from Data Stream	Two Pointers, Design, Sorting, Heap, Data Stream
300	Longest Increasing Subsequence	Array, Binary Search, Dynamic Programming
309	Best Time to Buy and Sell Stock with Cooldown	Array, Dynamic Programming
314	Binary Tree Vertical Order Traversal	Hash Table, Tree, Depth-First Search, Breadth-First Search, Sorting, Binary Tree
328	Odd Even Linked List	Linked List
329	Longest Increasing Path in a Matrix	Array, Dynamic Programming, Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort, Memoization, Matrix
338	Counting Bits	Dynamic Programming, Bit Manipulation
341	Flatten Nested List Iterator	Stack, Tree, Depth-First Search, Design, Queue, Iterator
347	Top K Frequent Elements	Array, Hash Table, Divide and Conquer, Sorting, Heap, Bucket Sort, Counting, Quickselect
362	Design Hit Counter	Array, Binary Search, Design, Queue, Data Stream
378	Kth Smallest Element in a Sorted Matrix	Array, Binary Search, Sorting, Heap, Matrix
380	Insert Delete GetRandom O(1)	Array, Hash Table, Math, Design, Randomized
394	Decode String	String, Stack, Recursion
410	Split Array Largest Sum	Array, Binary Search, Dynamic Programming, Greedy, Prefix Sum
412	Fizz Buzz	Math, String, Simulation
417	Pacific Atlantic Water Flow	Array, Depth-First Search, Breadth-First Search, Matrix
424	Longest Repeating Character Replacement	Hash Table, String, Sliding Window
428	Serialize and Deserialize N-ary Tree	String, Tree, Depth-First Search, Breadth-First Search
432	All O`one Data Structure	Hash Table, Linked List, Design, Doubly-Linked List
435	Non-overlapping Intervals	Array, Dynamic Programming, Greedy, Sorting
437	Path Sum III	Tree, Depth-First Search, Binary Tree
455	Assign Cookies	Array, Two Pointers, Greedy, Sorting
477	Total Hamming Distance	Array, Math, Bit Manipulation
496	Next Greater Element I	Array, Hash Table, Stack, Monotonic Stack
503	Next Greater Element II	Array, Stack, Monotonic Stack
535	Encode and Decode TinyURL	Hash Table, String, Design, Hash Function
542	01 Matrix	Array, Dynamic Programming, Breadth-First Search, Matrix
543	Diameter of Binary Tree	Tree, Depth-First Search, Binary Tree
560	Subarray Sum Equals K	Array, Hash Table, Prefix Sum
563	Binary Tree Tilt	Tree, Depth-First Search, Binary Tree
567	Permutation in String	Hash Table, Two Pointers, String, Sliding Window
611	Valid Triangle Number	Array, Two Pointers, Binary Search, Greedy, Sorting
621	Task Scheduler	Array, Hash Table, Greedy, Sorting, Heap, Counting
622	Design Circular Queue	Array, Linked List, Design, Queue
635	Design Log Storage System	Hash Table, String, Design, Ordered Set
658	Find K Closest Elements	Array, Two Pointers, Binary Search, Sliding Window, Sorting, Heap
662	Maximum Width of Binary Tree	Tree, Depth-First Search, Breadth-First Search, Binary Tree
674	Longest Continuous Increasing Subsequence	Array
687	Longest Univalue Path	Tree, Depth-First Search, Binary Tree
713	Subarray Product Less Than K	Array, Binary Search, Sliding Window, Prefix Sum
714	Best Time to Buy and Sell Stock with Transaction Fee	Array, Dynamic Programming, Greedy
727	Minimum Window Subsequence	String, Dynamic Programming, Sliding Window
733	Flood Fill	Array, Depth-First Search, Breadth-First Search, Matrix
736	Parse Lisp Expression	Hash Table, String, Stack, Recursion
739	Daily Temperatures	Array, Stack, Monotonic Stack
743	Network Delay Time	Depth-First Search, Breadth-First Search, Graph Theory, Heap, Shortest Path
746	Min Cost Climbing Stairs	Array, Dynamic Programming
759	Employee Free Time	Array, Sweep Line, Sorting, Heap
763	Partition Labels	Hash Table, Two Pointers, String, Greedy
772	Basic Calculator III	Math, String, Stack, Recursion
787	Cheapest Flights Within K Stops	Dynamic Programming, Depth-First Search, Breadth-First Search, Graph Theory, Heap, Shortest Path
815	Bus Routes	Array, Hash Table, Breadth-First Search
863	All Nodes Distance K in Binary Tree	Hash Table, Tree, Depth-First Search, Breadth-First Search, Binary Tree
875	Koko Eating Bananas	Array, Binary Search
889	Construct Binary Tree from Preorder and Postorder Traversal	Array, Hash Table, Divide and Conquer, Tree, Binary Tree
895	Maximum Frequency Stack	Hash Table, Stack, Design, Ordered Set
904	Fruit Into Baskets	Array, Hash Table, Sliding Window
918	Maximum Sum Circular Subarray	Array, Divide and Conquer, Dynamic Programming, Queue, Monotonic Queue
931	Minimum Falling Path Sum	Array, Dynamic Programming, Matrix
973	K Closest Points to Origin	Array, Math, Divide and Conquer, Geometry, Sorting, Heap, Quickselect
981	Time Based Key-Value Store	Hash Table, String, Binary Search, Design
987	Vertical Order Traversal of a Binary Tree	Hash Table, Tree, Depth-First Search, Breadth-First Search, Sorting, Binary Tree
994	Rotting Oranges	Array, Breadth-First Search, Matrix
1056	Confusing Number	Math
1064	Fixed Point	Array, Binary Search
1087	Brace Expansion	String, Backtracking, Stack, Breadth-First Search, Sorting
1146	Snapshot Array	Array, Hash Table, Binary Search, Design
1197	Minimum Knight Moves	Breadth-First Search
1235	Maximum Profit in Job Scheduling	Array, Binary Search, Dynamic Programming, Sorting
1283	Find the Smallest Divisor Given a Threshold	Array, Binary Search
1334	Find the City With the Smallest Number of Neighbors at a Threshold Distance	Dynamic Programming, Graph Theory, Shortest Path
1423	Maximum Points You Can Obtain from Cards	Array, Sliding Window, Prefix Sum
1448	Count Good Nodes in Binary Tree	Tree, Depth-First Search, Breadth-First Search, Binary Tree
1631	Path With Minimum Effort	Array, Binary Search, Depth-First Search, Breadth-First Search, Union-Find, Heap, Matrix
1641	Count Sorted Vowel Strings	Math, Dynamic Programming, Combinatorics
1740	Find Distance in a Binary Tree	Hash Table, Tree, Depth-First Search, Breadth-First Search, Binary Tree
1752	Check if Array Is Sorted and Rotated	Array
1804	Implement Trie II (Prefix Tree)	Hash Table, String, Design, Trie
2093	Minimum Cost to Reach City With Discounts	Graph Theory, Heap, Shortest Path
2095	Delete the Middle Node of a Linked List	Linked List, Two Pointers
2150	Find All Lonely Numbers in the Array	Array, Hash Table, Counting
2185	Counting Words With a Given Prefix	Array, String, String Matching
2435	Paths in Matrix Whose Sum Is Divisible by K	Array, Dynamic Programming, Matrix
2461	Maximum Sum of Distinct Subarrays With Length K	Array, Hash Table, Sliding Window
2487	Remove Nodes From Linked List	Linked List, Stack, Recursion, Monotonic Stack
2502	Design Memory Allocator	Array, Hash Table, Design, Simulation
2559	Count Vowel Strings in Ranges	Array, String, Prefix Sum
3249	Count the Number of Good Nodes	Tree, Depth-First Search
3408	Design Task Manager	Hash Table, Design, Heap, Ordered Set
3573	Best Time to Buy and Sell Stock V	Array, Dynamic Programming
3652	Best Time to Buy and Sell Stock using Strategy	Array, Sliding Window, Prefix Sum
3693	Climbing Stairs II	Array, Dynamic Programming