algo

Leetcode

arrays&hashing

Name	Star	Difficulty	Practice-Count	Tags
1. two-sum	⭐⭐⭐	easy	1
36. valid-sudoku		medium	1
49. group-anagrams		medium	2
128. longest-consecutive-sequence	⭐	medium	1
217. contains-duplicate		easy	1
238. product-of-array-except-self		medium	1
242. valid-anagram		easy	1
271. encode-and-decode-strings		medium	1
347. top-k-frequent-elements		medium	1

two-pointers

Name	Star	Difficulty	Practice-Count	Tags
11. container-with-most-water	⭐⭐⭐	medium	2
15. 3sum	⭐⭐⭐	medium	2
42. trapping-rain-water	⭐⭐⭐	hard	2
125. valid-palindrome		easy	1	todo(write)
167. two-sum-ii-input-array-is-sorted	⭐⭐⭐	medium	1

sliding-window

Name	Star	Difficulty	Practice-Count	Tags
3. longest-substring-without-repeating-characters	⭐⭐⭐	medium	1
76. minimum-window-substring	⭐	hard	1
121. best-time-to-buy-and-sell-stock	⭐	easy	1	todo(write)
239. sliding-window-maximum	⭐	hard	1
424. longest-repeating-character-replacement		medium	1
567. permutation-in-string		medium	1

stack

Name	Star	Difficulty	Practice-Count	Tags
20. valid-parentheses	⭐	easy	1	todo(write)
22. generate-parentheses	⭐⭐	medium	1	todo(write)
84. largest-rectangle-in-histogram	⭐⭐	hard	1
150. evaluate-reverse-polish-notation	⭐	medium	1
155. min-stack	⭐	medium	1
739. daily-temperatures	⭐	medium	1
853. car-fleet	⭐	medium	1

binary-search

Name	Star	Difficulty	Practice-Count	Tags
4. median-of-two-sorted-arrays	⭐⭐⭐	hard	1
33. search-in-rotated-sorted-array	⭐⭐	medium	1
74. search-a-2d-matrix	⭐	medium	1
153. find-minimum-in-rotated-sorted-array	⭐	medium	1
704. binary-search	⭐⭐⭐	easy	2
875. koko-eating-bananas	⭐	medium	1
981. time-based-key-value-store	⭐⭐	medium	1

linked-list

Name	Star	Difficulty	Practice-Count	Tags
2. add-two-numbers		medium	2
19. remove-nth-node-from-end-of-list	⭐	medium	2
21. merge-two-sorted-lists	⭐⭐⭐	easy	2
23. merge-k-sorted-lists	⭐⭐⭐	hard	2
25. reverse-nodes-in-k-group	⭐⭐	hard	2
138. copy-list-with-random-pointer	⭐⭐⭐	medium	2
141. linked-list-cycle	⭐⭐⭐	easy	2	todo(write)
143. reorder-list	⭐	medium	1
146. lru-cache	⭐⭐⭐	medium	1
206. reverse-linked-list	⭐	easy	2
287. find-the-duplicate-number	⭐⭐⭐	medium	2

trees

Name	Star	Difficulty	Practice-Count	Tags
98. validate-binary-search-tree	⭐	medium	1
100. same-tree	⭐	easy	2
102. binary-tree-level-order-traversal	⭐	medium	1
104. maximum-depth-of-binary-tree	⭐⭐⭐	easy	2
105. construct-binary-tree-from-preorder-and-inorder-traversal	⭐⭐	medium	1
110. balanced-binary-tree	⭐⭐	easy	2
124. binary-tree-maximum-path-sum	⭐⭐⭐	hard	1
199. binary-tree-right-side-view	⭐⭐	medium	1
226. invert-binary-tree	⭐	easy	2
230. kth-smallest-element-in-a-bst	⭐⭐	medium	1
235. lowest-common-ancestor-of-a-binary-search-tree	⭐⭐	medium	1	todo(write)
297. serialize-and-deserialize-binary-tree	⭐	hard	1
543. diameter-of-binary-tree	⭐	easy	1
572. subtree-of-another-tree	⭐⭐	easy	1
1448. count-good-nodes-in-binary-tree	⭐⭐	medium	1

tries

Name	Star	Difficulty	Practice-Count	Tags
208. implement-trie-prefix-tree		medium	2
211. design-add-and-search-words-data-structure		medium	1
212. word-search-ii	⭐⭐⭐	hard	1

heap(priority-queue)

Name	Star	Difficulty	Practice-Count	Tags
215. kth-largest-element-in-an-array	⭐	medium	1	PR
295. find-median-from-data-stream	⭐⭐	hard	1
355. design-twitter	⭐⭐⭐	medium	1
621. task-scheduler	⭐⭐⭐	medium	1
703. kth-largest-element-in-a-stream	⭐	easy	1
973. k-closest-points-to-origin	⭐⭐	medium	1
1046. last-stone-weight	⭐⭐	easy	1

backtracking

Name	Star	Difficulty	Practice-Count	Tags
17. letter-combinations-of-a-phone-number	⭐	medium	1
39. combination-sum	⭐⭐⭐	medium	1
40. combination-sum-ii	⭐⭐⭐	medium	1
46. permutations	⭐⭐	medium	1
51. n-queens	⭐⭐⭐	hard	1
78. subsets	⭐⭐⭐	medium	1
79. word-search	⭐⭐	medium	1
90. subsets-ii	⭐⭐⭐	medium	1
131. palindrome-partitioning	⭐	medium	1

graphs

Name	Star	Difficulty	Practice-Count	Tags
127. word-ladder	⭐⭐	hard	1
130. surrounded-regions	⭐⭐	medium	1	todo(write)
133. clone-graph	⭐	medium	1
200. number-of-islands	⭐	medium	1	todo(write)
207. course-schedule	⭐⭐	medium	1
210. course-schedule-ii	⭐⭐⭐	medium	1	topological-sort
261. graph-valid-tree		medium	1	union-find, dfs, leet-code-premium
286. walls-and-gates		medium	1	bfs, leet-code-premium
323. number-of-connected-components-in-an-undirected-graph		medium	1	union-find, leet-code-premium
417. pacific-atlantic-water-flow	⭐⭐⭐	medium	1	todo(write)
684. redundant-connection		medium	1	union-find
695. max-area-of-island	⭐	medium	1
994. rotting-oranges	⭐⭐	medium	1

advanced-graphs

Name	Star	Difficulty	Practice-Count	Tags
269. alien-dictionary	⭐⭐⭐	hard	1	PR, YT, leet-code-premium
332. reconstruct-itinerary	⭐⭐⭐	hard	1	PR
743. network-delay-time	⭐⭐⭐	medium	1	dijkstra's-algo
778. swim-in-rising-water	⭐⭐⭐	hard	1	dijkstra's-algo
787. cheapest-flights-within-k-stops	⭐⭐⭐	medium	1	bellman-ford-algo
1584. min-cost-to-connect-all-points	⭐⭐⭐	medium	1	prim's-algo, kruskal-algo(todo), leet-code-premium, heap

1d-dp

Name	Star	Difficulty	Practice-Count	Tags
5. longest-palindromic-substring		medium	1
70. climbing-stairs	⭐⭐⭐	easy	2
91. decode-ways	⭐⭐⭐	medium	1
139. word-break	⭐⭐	medium	1
152. maximum-product-subarray		medium	1	todo(write)
198. house-robber	⭐	medium	3
213. house-robber-ii	⭐⭐⭐	medium	3
300. longest-increasing-subsequence	⭐	medium	1	todo(write)
322. coin-change	⭐⭐⭐	medium	3
416. partition-equal-subset-sum	⭐⭐	medium	1
647. palindromic-substrings	⭐	medium	1
746. min-cost-climbing-stairs	⭐⭐	easy	2

2d-dp

Name	Star	Difficulty	Practice-Count	Tags
10. regular-expression-matching		hard	1
62. unique-paths		medium	2	math(todo)
72. edit-distance	⭐⭐⭐	medium	1	todo(write)
97. interleaving-string	⭐⭐⭐	medium	1	dfs
115. distinct-subsequences	⭐⭐⭐	hard	1	lcs
309. best-time-to-buy-and-sell-stock-with-cooldown	⭐⭐⭐	medium	1	dfs, todo-space-optimize
312. burst-balloons	⭐⭐	hard	1
329. longest-increasing-path-in-a-matrix	⭐⭐	hard	1	topological-sort
494. target-sum	⭐⭐⭐	medium	2	dfs
518. coin-change-ii	⭐⭐⭐	medium	3	dfs
1143. longest-common-subsequence	⭐⭐⭐	medium	1	todo(write)

greedy

Name	Star	Difficulty	Practice-Count	Tags
45. jump-game-ii		medium	1	dp(todo)
53. maximum-subarray	⭐⭐	medium	2
55. jump-game	⭐⭐⭐	medium	2
134. gas-station	⭐⭐	medium	1
678. valid-parenthesis-string		medium	1
763. partition-labels		medium	1
846. hand-of-straights		medium	1
1899. merge-triplets-to-form-target-triplet		medium	1

intervals

Name	Star	Difficulty	Practice-Count	Tags
56. merge-intervals		medium	1
57. insert-interval		medium	1
253. meeting-rooms-ii		medium	1
435. non-overlapping-intervals		medium	1
920. meeting-rooms		hard	1
1851. minimum-interval-to-include-each-query		hard	1

math&geometry

Name	Star	Difficulty	Practice-Count	Tags
43. multiply-strings		medium	1
48. rotate-image		medium	1
50. powx-n		medium	1
54. spiral-matrix		medium	1
66. plus-one		easy	1
73. set-matrix-zeroes		medium	1
202. happy-number	⭐⭐	easy	1
213. detect-squares		medium	1

bit-manipulation

Name	Star	Difficulty	Practice-Count	Tags
7. reverse-integer		medium	1	PR
136. single-number		easy	1
190. reverse-bits		easy	1
191. number-of-1-bits		easy	1
268. missing-number		easy	1
338. counting-bits		easy	1
371. sum-of-two-integers		medium	1

todo

Name	Star	Difficulty	Practice-Count	Tags