README.md

My Leetcode

My LeetCode homepage : hunterxmoon - Leetcode

No.	Leetcode Link	To My Solution	Tag	Difficulty	Review Needed
1	leetcode283_move-zeroes	MoveZeroes	Array		❌
2	leetcode27_remove-element	MoveElement	Array		❌
3	leetcode26_remove-duplicates-from-sorted-array	remove-duplicates-from-sorted-array	Array		❌
4	leetcode80_remove-duplicates-from-sorted-array-ii	remove-duplicates-from-sorted-array-ii	Array		✅
5	leetcode75_sort-colors	sort-colors	Array, Sort		❌
6	leetcode88_merge-sorted-array	merge-sorted-array	Array		❌
7	leetcode215_kth-largest-element-in-an-array	kth-largest-element-in-an-array	Array, Sort		✅
8	leetcode1_two-sum	two-sum	Array		❌
9	leetcode167_two-sum-ii-input-array-is-sorted	two-sum-ii-input-array-is-sorted	Array		❌
10	leetcode125_valid-palindrome	valid-palindrome	String		✅
11	leetcode345_reverse-vowels-of-a-string	reverse-vowels-of-a-string	String		❌
12	leetcode11_container-with-most-water	container-with-most-water	Array		✅
13	leetcode209_minimum-size-subarray-sum	minimum-size-subarray-sum	Array		✅
14	leetcode242_valid-anagram	valid-anagram	String		❌
15	leetcode438_find-all-anagrams-in-a-string	find-all-anagrams-in-a-string	String		❌
16	leetcode76_minimum-window-substring	minimum-window-substring	String		✅
17	leetcode349_intersection-of-two-arrays	intersection-of-two-arrays	Array, Search		❌
18	leetcode350_intersection-of-two-arrays-ii	intersection-of-two-arrays-ii	Array, Search		❌
19	leetcode202_happy-number	happy-number	Search		✅
20	leetcode290_word-pattern	word-pattern	Search		❌
21	leetcode205_isomorphic-strings	isomorphic-strings	Search		❌
22	leetcode451_sort-characters-by-frequency	sort-characters-by-frequency	Search		❌
23	leetcode15_3sum	3sum	Search		✅
24	leetcode18_4sum	4sum	Search		✅
25	leetcode16_3SumClosest	3SumClosest	Search		✅
26	leetcode454_4sum-ii	4sum-ii	Search		❌
27	leetcode49_group-anagrams	group-anagrams	Search, String		✅
28	leetcode447_number-of-boomerangs	number-of-boomerangs	Search, geometric		✅
29	leetcode149_max-points-on-a-line	max-points-on-a-line	Search, geometric		✅
30	leetcode217_contains-duplicate	contains-duplicate	Search		❌
31	leetcode219_contains-duplicate-ii	contains-duplicate-ii	Search		❌
32	leetcode220_contains-duplicate-iii	contains-duplicate-iii	Search		✅
33	leetcode226_reverse-linked-list	reverse-linked-list	LinkedList		✅
34	leetcode92_reverse-linked-list-ii	reverse-linked-list-ii	LinkedList		✅
35	leetcode83_remove-duplicates-from-sorted-list	remove-duplicates-from-sorted-list	LinkedList		❌
36	leetcode86_Partition List	partition-list	LinkedList		❌
37	leetcode328_odd-even-linked-list	odd-even-linked-list	LinkedList		❌
38	leetcode2_add-two-numbers	add-two-numbers	LinkedList		❌
39	leetcode445_add-two-numbers-ii	add-two-numbers-ii	LinkedList		❌
40	leetcode203_remove-linked-list-elements	remove-linked-list-elements	LinkedList		❌
41	leetcode82_remove-duplicates-from-sorted-list-ii	remove-duplicates-from-sorted-list-ii	LinkedList		✅
42	leetcode21_merge-two-sorted-lists	merge-two-sorted-lists	LinkedList		❌
43	leetcode24_swap-nodes-in-pairs	swap-nodes-in-pairs	LinkedList		❌
44	leetcode25_reverse-nodes-in-k-group	reverse-nodes-in-k-group	LinkedList		✅
45	leetcode147_insertion-sort-list	insertion-sort-list	LinkedList		✅
46	leetcode148_sort-list	sort-list	LinkedList		✅
47	leetcode237_delete-node-in-a-linked-list	delete-node-in-a-linked-list	LinkedList		✅
48	leetcode19_remove-nth-node-from-end-of-list	remove-nth-node-from-end-of-list	LinkedList		✅
49	leetcode61_rotate-list	rotate-list	LinkedList		✅
50	leetcode143_reorder-list	reorder-list	LinkedList		✅
51	leetcode234_palindrome-linked-list	palindrome-linked-list	LinkedList		✅
52	leetcode20_valid-parentheses	valid-parentheses	Stack		❌
53	leetcode150_evaluate-reverse-polish-notation	evaluate-reverse-polish-notation	Stack		❌
54	leetcode71_simplify-path	simplify-path	Stack		❌
55	leetcode144_binary-tree-preorder-traversal	binary-tree-preorder-traversal	Tree, Stack		✅
56	leetcode94_binary-tree-inorder-traversal	binary-tree-preorder-traversal	Tree, Stack		✅
57	leetcode145_binary-tree-postorder-traversal	binary-tree-postorder-traversal	Tree, Stack		✅
58	leetcode341_flatten-nested-list-iterator	flatten-nested-list-iterator	Tree, Stack		❌
59	leetcode102_binary-tree-level-order-traversal	binary-tree-level-order-traversal	Tree, Stack		✅
60	leetcode107_binary-tree-level-order-traversal-ii	binary-tree-level-order-traversal-ii	Tree, Stack		❌
61	leetcode103_binary-tree-zigzag-level-order-traversal	binary-tree-zigzag-level-order-traversal	Tree, Stack		✅
62	leetcode199_binary-tree-right-side-view	binary-tree-right-side-view	Tree, Stack		❌
63	leetcode279_perfect-squares	perfect-squares	Graph, Stack, DP		✅
64	leetcode347_top-k-frequent-elements	top-k-frequent-elements	PriorityQueue		❌
65	leetcode23_merge-k-sorted-lists	merge-k-sorted-lists	PriorityQueue, LinkedList		✅
66	leetcode104_maximum-depth-of-binary-tree	maximum-depth-of-binary-tree	Recursive, Tree		❌
67	leetcode100_same-tree	same-tree	Recursive, Tree		❌
68	leetcode101_symmetric-tree	symmetric-tree	Recursive, Tree		✅
69	leetcode222_count-complete-tree-nodes	count-complete-tree-nodes	PriorityQueue, tree		✅
70	leetcode70_climbing-stairs	climbing-stairs	DP		❌
71	leetcode120_triangle	triangle	DP		✅
72	leetcode110_balanced-binary-tree	balanced-binary-tree	Tree, Recursive		✅
73	leetcode112_path-sum	path-sum	Tree, Recursive		✅
74	leetcode111_minimum-depth-of-binary-tree	minimum-depth-of-binary-tree	Tree, Recursive		✅
75	leetcode404_sum-of-left-leaves	sum-of-left-leaves	Tree, Recursive		✅
76	leetcode64_minimum-path-sum	minimum-path-sum	DP		❌
77	leetcode343_integer-break	integer-break	DP, Recursive		✅
78	leetcode91_decode-ways	decode-ways	DP, Recursive		✅
79	leetcode62_unique-paths	unique-paths	DP, Recursive		❌
80	leetcode63_unique-paths-ii	unique-paths-ii	DP, Recursive		❌
81	leetcode198_house-robber	house-robber	DP, Recursive		✅
82	leetcode257_binary-tree-paths	binary-tree-paths	Tree, Recursive		❌
83	leetcode113_path-sum-ii	path-sum-ii	Tree, Recursive		❌
84	leetcode129_sum-root-to-leaf-numbers	sum-root-to-leaf-numbers	Tree, Recursive		❌
85	leetcode437_path-sum-iii	path-sum-iii	Tree, Recursive		✅
86	leetcode235_lowest-common-ancestor-of-a-binary-search-tree	lowest-common-ancestor-of-a-binary-search-tree	Tree, Recursive		❌
87	leetcode98_validate-binary-search-tree	validate-binary-search-tree	Tree, Recursive		✅
88	leetcode450_delete-node-in-a-bst	delete-node-in-a-bst	BST		✅
89	leetcode108_convert-sorted-array-to-binary-search-tree	convert-sorted-array-to-binary-search-tree	BST		❌
90	leetcode230_kth-smallest-element-in-a-bst	kth-smallest-element-in-a-bst	BST		❌
91	leetcode236_lowest-common-ancestor-of-a-binary-tree	lowest-common-ancestor-of-a-binary-tree	BST		✅
92	leetcode213_house-robber-ii	house-robber-ii	DP		✅
93	leetcode17_letter-combinations-of-a-phone-number	letter-combinations-of-a-phone-number	Recursive		❌
94	leetcode131_palindrome-partitioning	palindrome-partitioning	Recursive		✅
95	leetcode93_restore-ip-addresses	restore-ip-addresses	Recursive		❌
96	leetcode46_permutations	permutations	Recursive		✅
97	leetcode47_permutations-ii	permutations-ii	Recursive		✅
98	leetcode77_combinations	combinations	Recursive		✅
99	leetcode39_combination-sum	combination-sum	Recursive		✅
100	leetcode40_combination-sum-ii	combination-sum-ii	Recursive		✅
101	leetcode216_combination-sum-iii	combination-sum-iii	Recursive		✅
102	leetcode78_subsets	subsets	Recursive		✅
103	leetcode90_subsets-ii	subsets-ii	Recursive		✅
104	leetcode7_reverse-integer	reverse-integer	Math		✅
105	leetcode9_palindrome-number	palindrome-number	Math		❌
106	leetcode13_roman-to-integer	roman-to-integer	Math		❌
107	leetcode14_longest-common-prefix	longest-common-prefix	String		❌
108	leetcode28_implement-strstr	implement-strstr	String		✅
109	leetcode79_word-search	subsets-ii	Recursive		✅
110	leetcode200_number-of-islands	number-of-islands	Recursive		✅
111	leetcode130_surrounded-regions	surrounded-regions	Recursive		✅✅
//	112	leetcode417_pacific-atlantic-water-flow	pacific-atlantic-water-flow	Recursive
113	leetcode35_search-insert-position	search-insert-position	Search		❌
114	leetcode3_longest-substring-without-repeating-characters	longest-substring-without-repeating-characters	String		❌
115	leetcode5_longest-palindromic-substring	longest-palindromic-substring	String, DP		✅
116	leetcode6_zigzag-conversion	zigzag-conversion	String, Math		❌
117	leetcode51_n-queens	n-queens	BackTracking		✅
118	leetcode416_partition-equal-subset-sum	partition-equal-subset-sum	DP		✅
119	leetcode213_house-robber-ii	house-robber-ii	DP		✅
120	leetcode337_house-robber-iii	house-robber-iii	DP		✅
121	leetcode322_coin-change	coin-change	DP		✅
122	leetcode377_combination-sum-iv	combination-sum-iv	DP		✅
123	leetcode139_word-break	word-break	DP		✅
124	leetcode474_ones-and-zeroes	ones-and-zeroes	DP		✅
125	leetcode53_maximum-subarray	maximum-subarray	DP		✅
126	leetcode66_plus-one	plus-one	array		❌
127	leetcode121_best-time-to-buy-and-sell-stock	best-time-to-buy-and-sell-stock	dp		✅
128	leetcode122_best-time-to-buy-and-sell-stock-ii	best-time-to-buy-and-sell-stock-ii	dp		✅
129	leetcode309_best-time-to-buy-and-sell-stock-with-cooldown	best-time-to-buy-and-sell-stock-with-cooldown	dp		✅
130	leetcode118_Pascals-Triangle	Pascals-Triangle	array		❌
131	leetcode119_Pascals-Triangle-II	Pascals-Triangle-II	array		❌
132	leetcode141_linked-list-cycle	linked-list-cycle	linklist		❌
133	leetcode300_longest-increasing-subsequence	longest-increasing-subsequence	dp		❌
134	leetcode376_wiggle-subsequence	wiggle-subsequence	Greedy		✅
135	leetcode455_assign-cookies	wiggle-subsequence	Greedy		❌
136	leetcode392_is-subsequence	is-subsequence	Greedy		❌
137	leetcode435_non-overlapping-intervals	non-overlapping-intervals	Greedy		✅
138	leetcode22_generate-parentheses	generate-parentheses	Greedy		✅
139	leetcode33_search-in-rotated-sorted-array	search-in-rotated-sorted-array	binarySearch		✅
140	leetcode43_multiply-strings	multiply-strings	String		❌
141	leetcode48_rotate-image	rotate-image	Math		✅
142	leetcode50_powx-n	powx-n	Math		✅
143	leetcode54_spiral-matrix	spiral-matrix	BFS,DFS		✅
144	leetcode55_jump-game	jump-game	Math		✅
145	leetcode56_merge-intervals	merge-intervals	Array		❌
146	leetcode57_insert-interval	insert-interval	Array		✅
147	leetcode58_length-of-last-word	length-of-last-word	Array		❌
148	leetcode59_spiral-matrix-ii	spiral-matrix-ii	Array		✅
149	leetcode60_permutation-sequence	permutation-sequence	Array		✅
150	leetcode67_add-binary	add-binary	String		❌
151	leetcode69_sqrtx	sqrtx	String		✅
152	leetcode73_set-matrix-zeroes	set-matrix-zeroes	Array		✅
153	leetcode74_search-a-2d-matrix	search-a-2d-matrix	Array		✅
154	leetcode81_search-in-rotated-sorted-array-ii	search-in-rotated-sorted-array-ii	Array		✅
155	leetcode89_gray-code	gray-code	Recursive		✅
156	leetcode96_unique-binary-search-trees	unique-binary-search-trees	DP		✅✅
157	leetcode31_next-permutation	next-permutation	Array		✅
158	leetcode95_unique-binary-search-trees-ii	unique-binary-search-trees-ii	Recursive		✅✅
159	leetcode36_valid-sudoku	valid-sudoku	Array		❌
160	leetcode41_first-missing-positive	first-missing-positive	Array		✅
161	leetcode155_min-stack	min-stack	Stack		✅
162	leetcode160_intersection-of-two-linked-lists	intersection-of-two-linked-lists	ListNode		❌
163	leetcode169_majority-element	majority-element	Array		❌
164	leetcode172_factorial-trailing-zeroes	majority-element	Math		✅
165	leetcode171_excel-sheet-column-number	excel-sheet-column-number	Math		❌
166	leetcode268_missing-number	missing-number	Array		❌
167	leetcode326_power-of-three	power-of-three	Math		✅
168	leetcode344_reverse-string	reverse-string	String		❌
169	leetcode387_first-unique-character-in-a-string	first-unique-character-in-a-string	Math		❌
170	leetcode189_rotate-array	rotate-array	Math		✅
171	leetcode105_construct-binary-tree-from-preorder-and-inorder-traversal	construct-binary-tree-from-preorder-and-inorder-traversal	Tree		✅
172	leetcode116_populating-next-right-pointers-in-each-node	populating-next-right-pointers-in-each-node	Tree		✅
173	leetcode617_merge-two-binary-trees	merge-two-binary-trees	Tree		❌
174	leetcode238_product-of-array-except-self	product-of-array-except-self	Array		✅
175	leetcode287_find-the-duplicate-number	find-the-duplicate-number	Array		✅
176	leetcode162_find-peak-element	find-peak-element	BinarySearch		✅
177	leetcode179_largest-number	largest-number	Array,String		✅
178	leetcode378_kth-smallest-element-in-a-sorted-matrix	kth-smallest-element-in-a-sorted-matrix	PriorityQueue, BinarySearch		✅
179	leetcode240_search-a-2d-matrix-ii	search-a-2d-matrix-ii	DivideAndConker		✅
180	leetcode239_sliding-window-maximum	sliding-window-maximum	Stack		✅
181	leetcode412_fizz-buzz	fizz-buzz	Mimic		❌
182	leetcode42_trapping-rain-water	trapping-rain-water	DP, Two-Point		✅
183	leetcode84_largest-rectangle-in-histogram	largest-rectangle-in-histogram	Stack,Two-Point		✅
184	leetcode152_maximum-product-subarray	maximum-product-subarray	DP		✅
185	leetcode334_increasing-triplet-subsequence	increasing-triplet-subsequence	DP		✅
186	leetcode29_divide-two-integers	divide-two-integers	Math		✅
187	leetcode65_valid-number	valid-number	Math		✅
188	leetcode140_word-break-ii	word-break-ii	Backtrack, DP		✅
189	leetcode647_palindromic-substrings	palindromic-substrings	TwoPoint		✅

Binary Search

https://www.liwei.party/2019/06/19/leetcode-solution-new/search-insert-position/#toc-heading-5 https://www.educative.io/courses/coderust-hacking-the-coding-interview/lYg2l

backtracking

401 417 37

Graph

279 / 127 / 126

Best Time to Buy and Sell Stock

123 188

0-1 pack

494

Leetcode Retag

• Pre Sum (hash map)

  • 1. Two Sum
  • 15. 3Sum
  • 18. 4Sum
  • 410. Split Array Largest Sum
  • 560. Subarray Sum Equals K

• Calculation

  • 2. Add Two Numbers
  • 13. Roman to Integer
  • 31. Next Permutation
  • 134. Gas Station
  • 166. Fraction to Recurring Decimal
  • 202. Happy Number
  • 238. Product of Array Except Self
  • 273. Integer to English Words
  • 334. Increasing Triplet Subsequence
  • 621. Task Scheduler

• Monotonous Stack

  • 42. Trapping Rain Water
  • 84. Largest Rectangle in Histogram
  • 85. Maximal Rectangle
  • 456. 132 Pattern
  • 735. Asteroid Collision
  • 739. Daily Temperatures

• Decode Stack / DFS

  • 341. Flatten Nested List Iterator
  • 394. Decode String
  • 726. Number of Atoms
  • 1087. Brace Expansion

• Sort First

  • 16. 3Sum Closest
  • 56. Merge Intervals
  • 57. Insert Interval
  • 253. Meeting Rooms II

• Matrix Loop

  • 48. Rotate Image
  • 54. Spiral Matrix
  • 59. Spiral Matrix II
  • 498. Diagonal Traverse

• Trie Tree

  • 208. Implement Trie (Prefix Tree)
  • 211. Add and Search Word - Data structure design

• Data Structure Design

  • 146. LRU Cache
  • 155. Min Stack
  • 158. Read N Characters Given Read4 II - Call multiple times
  • 173. Binary Search Tree Iterator
  • 297. Serialize and Deserialize Binary Tree
  • 449. Serialize and Deserialize BST
  • 981. Time Based Key-Value Store

• Hash map compare

  • 49. Group Anagrams

• Palindromic Substring

  • 5. Longest Palindromic Substring

• Merge Sort

  • 4. Median of Two Sorted Arrays
  • 21. Merge Two Sorted Lists
  • 23. Merge k Sorted Lists
  • 88. Merge Sorted Array
  • 148. Sort List

• Merge Combine Sort

  • 315. Count of Smaller Numbers After Self

• Two Pointer Slide window

  • 3. Longest Substring Without Repeating Characters
  • 76. Minimum Window Substring
  • 159. Longest Substring with At Most Two Distinct Characters
  • 209. Minimum Size Subarray Sum
  • 340. Longest Substring with At Most K Distinct Characters
  • 438. Find All Anagrams in a String
  • 567. Permutation in String
  • 727. Minimum Window Subsequence

• Two Pointer

  • 11. Container With Most Water

• Heap (K elements)

  • 215. Kth Largest Element in an Array
  • 239. Sliding Window Maximum
  • 347. Top K Frequent Elements
  • 787. Cheapest Flights Within K Stops
  • 973. K Closest Points to Origin

• Multiple Heap

  • 295. Find Median from Data Stream

• Basic DFS

  • 17. Letter Combinations of a Phone Number
  • 22. Generate Parentheses
  • 37. Sudoku Solver
  • 39. Combination Sum
  • 46. Permutations
  • 78. Subsets
  • 79. Word Search
  • 200. Number of Islands
  • 210. Course Schedule II
  • 212. Word Search II
  • 282. Expression Add Operators
  • 322. Coin Change
  • 403. Frog Jump

• DFS Hard

  • 51. N-Queens
  • 140. Word Break II
  • 489. Robot Room Cleaner

• Basic BFS

  • 64. Minimum Path Sum
  • 126. Word Ladder II
  • 207. Course Schedule
  • 863. All Nodes Distance K in Binary Tree

• Topological Sort

  • 207. Course Schedule
  • 210. Course Schedule II
  • 269. Alien Dictionary

• Basic Binary Search

  • 33. Search in Rotated Sorted Array
  • 34. Find First and Last Position of Element in Sorted Array
  • 81. Search in Rotated Sorted Array II
  • 153. Find Minimum in Rotated Sorted Array
  • 154. Find Minimum in Rotated Sorted Array II
  • 162. Find Peak Element
  • 240. Search a 2D Matrix II

• Binary Search Hard

  • 214. Shortest Palindrome
  • 287. Find the Duplicate Number
  • 528. Random Pick with Weight
  • 647. Palindromic Substrings
  • 1055. Shortest Way to Form String

• DP Stock

  • 121. Best Time to Buy and Sell Stock
  • 122. Best Time to Buy and Sell Stock II
  • 123. Best Time to Buy and Sell Stock III
  • 188. Best Time to Buy and Sell Stock IV

• Basic DP

  • 10. Regular Expression Matching
  • 36. Valid Sudoku
  • 44. Wildcard Matching
  • 45. Jump Game II
  • 62. Unique Paths
  • 70. Climbing Stairs
  • 91. Decode Ways
  • 96. Unique Binary Search Trees
  • 97. Interleaving String
  • 128. Longest Consecutive Sequence
  • 152. Maximum Product Subarray
  • 139. Word Break
  • 198. House Robber
  • 221. Maximal Square
  • 256. Paint House
  • 300. Longest Increasing Subsequence

• Swap Trick

  • 41. First Missing Positive
  • 75. Sort Colors
  • 283. Move Zeroes

• Random

  • 528. Random Pick with Weight

• Stack Basic

  • 7. Reverse Integer
  • 20. Valid Parentheses
  • 150. Evaluate Reverse Polish Notation
  • 224. Basic Calculator
  • 227. Basic Calculator II
  • 772. Basic Calculator III

• Bruce Force

  • 1007. Minimum Domino Rotations For Equal Row

• Serialize and Deserialize

  • 297. Serialize and Deserialize Binary Tree

• Tree Recursion

  • 124. Binary Tree Maximum Path Sum
  • 236. Lowest Common Ancestor of a Binary Tree
  • 543. Diameter of Binary Tree
  • 834. Sum of Distances in Tree

• Tree Non Recursion

  • 116. Populating Next Right Pointers in Each Node
  • 117. Populating Next Right Pointers in Each Node II
  • 199. Binary Tree Right Side View

• Validate Tree

  • 98. Validate Binary Search Tree

• Construct or recover Tree

  • 99. Recover Binary Search Tree
  • 105. Construct Binary Tree from Preorder and Inorder Traversal
  • 109. Convert Sorted List to Binary Search Tree

• Clone

  • 138. Copy List with Random Pointer
  • 133. Clone Graph