README.md

✏️ Leetcode Solutions with Java

Update time: 2019-07-09 23:08:48

I have solved 220 / 1113 problems

If you have any question, please give me an issue.

If you are loving solving problems in leetcode, please contact me to enjoy it together!

(Notes: 🔒 means you need to buy a book from Leetcode to unlock the problem)

#	Title	Source Code	Article	Difficulty
1	two-sum	Java	📝	Easy
2	add-two-numbers	Java	📝	Medium
3	longest-substring-without-repeating-characters	Java	📝	Medium
5	longest-palindromic-substring	Java	📝	Medium
7	reverse-integer	Java	📝	Easy
9	palindrome-number	Java	📝	Easy
11	container-with-most-water	Java	📝	Medium
12	integer-to-roman	Java		Medium
13	roman-to-integer	Java		Easy
14	longest-common-prefix	Java	📝	Easy
15	3sum	Java		Medium
17	letter-combinations-of-a-phone-number	Java	📝	Medium
19	remove-nth-node-from-end-of-list	Java	📝	Medium
20	valid-parentheses	Java	📝	Easy
21	merge-two-sorted-lists	Java	📝	Easy
22	generate-parentheses	Java	📝	Medium
23	merge-k-sorted-lists	Java	📝	Hard
24	swap-nodes-in-pairs	Java	Medium
26	remove-duplicates-from-sorted-array	Java	📝	Easy
27	remove-element	Java	📝	Easy
28	implement-strstr	Java		Easy
29	divide-two-integers	Java		Medium
31	next-permutation	Java	📝	Medium
32	longest-valid-parentheses	Java	📝	Hard
33	search-in-rotated-sorted-array	Java	📝	Medium
34	find-first-and-last-position-of-element-in-sorted-array	Java	📝	Medium
35	search-insert-position	Java		Easy
36	valid-sudoku	Java	📝	Medium
39	combination-sum	Java		Medium
30	combination-sum-ii	Java		Medium
42	trapping-rain-water	Java	📝	Hard
46	permutations	Java	📝	Medium
47	permutations-ii	Java		Medium
48	rotate-image	Java	📝	Medium
49	group-anagrams	Java	📝	Medium
50	powx-n	Java	Medium
53	maximum-subarray	Java	📝	Easy
54	spiral-matrix	Java	Medium
55	jump-game	Java	📝	Medium
56	merge-intervals	Java	📝	Medium
59	spiral-matrix-ii	Java	Medium
60	permutation-sequence	Java		Medium
61	rotate-list	Java		Medium
62	unique-paths	Java		Medium
63	unique-paths-ii	Java		Medium
64	minimum-path-sum	Java	📝	Medium
66	plus-one	Java		Easy
69	sqrtx	Java		Easy
70	climbing-stairs	Java	📝	Easy
71	simplify-path	Java	Medium
72	edit-distance	Java	📝	Hard
73	set-matrix-zeroes	Java	📝	Medium
74	search-a-2d-matrix	Java	Medium
75	sort-colors	Java	📝	Medium
76	minimum-window-substring	Java		Medium
77	combinations	Java		Medium
78	subsets	Java		Medium
79	word-search	Java		Medium
81	search-in-rotated-sorted-array-ii	Java	Medium
82	remove-duplicates-from-sorted-list-ii	Java	Medium
83	remove-duplicates-from-sorted-list	Java	Easy
86	partition-list	Java	Medium
88	merge-sorted-array	Java	📝	Easy
89	grey-code	Java	Medium
90	subsets-ii	Java		Medium
92	reverse-linked-list-ii	Java		Medium
94	binary-tree-inorder-traversal	Java	📝	Medium
96	unique-binary-search-trees	Java	📝	Medium
98	validate-binary-search-tree	Java	📝	Medium
101	symmetric-tree	Java	📝	Easy
102	binary-tree-level-order-traversal	Java	📝	Medium
103	binary-tree-zigzag-level-order-traversal	Java		Medium
104	maximum-depth-of-binary-tree	Java	📝	Easy
105	construct-binary-tree-from-preorder-and-inorder-traversal	Java	📝	Medium
108	convert-sorted-array-to-binary-search-tree	Java		Easy
110	balanced-binary-tree	Java		Easy
111	minimum-depth-of-binary-tree	Java	📝	Easy
112	path-sum	Java		Easy
113	path-sum-ii	Java		Medium
114	flatten-binary-tree-to-linked-list	Java		Medium
118	pascals-triangle	Java	📝	Easy
121	best-time-to-buy-and-sell-stock	Java	📝	Easy
122	best-time-to-buy-and-sell-stock-ii	Java	📝	Easy
127	word-ladder	Java	Medium
128	longest-consecutive-sequence	Java	📝	Hard
131	palindrome-partitioning	Java		Medium
134	gas-station	Java	📝	Medium
136	single-number	Java	📝	Easy
138	copy-list-with-random-pointer	Java	Medium
139	word-break	Java	📝	Medium
141	linked-list-cycle	Java	📝	Easy
142	linked-list-cycle-ii	Java	📝	Medium
144	binary-tree-preorder-traversal	Java	📝	Medium
145	binary-tree-postorder-traversal	Java	📝	Hard
146	lru-cache	Java		Medium
148	sort-list	Java		Medium
151	reverse-word-in-a-string	Java		Medium
152	maximum-product-subarray	Java		Medium
155	min-stack	Java		Easy
160	intersection-of-two-linked-lists	Java	📝	Easy
162	find-peak-element	Java	📝	Medium
167	two-sum-ii-input-array-is-sorted	Java	📝	Easy
169	majority-element	Java	📝	Easy
171	excel-sheet-column-number	Java		Easy
172	factorial-trailing-zeroes	Java		Easy
189	rotate-array	Java	📝	Easy
190	reverse-bits	Java		Easy
191	number-of-1-bits	Java	📝	Easy
198	house-robber	Java	📝	Easy
200	number-of-islands	Java	📝	Medium
202	happy-number	Java		Easy
203	remove-linked-list-elements	Java		Easy
204	count-primes	Java		Easy
206	reverse-linked-list	Java	📝	Easy
207	course-schedule	Java		Medium
208	implement-trie-prefix-tree	Java	📝	Medium
215	kth-largest-element-in-an-array	Java	📝	Medium
217	contains-duplicate	Java	📝	Easy
221	maximal-square	Java	📝	Medium
225	implement-stack-using-queues	Java	Easy
226	invert-binary-tree	Java	📝	Easy
230	kth-smallest-element-in-a-bst	Java	📝	Medium
232	implement-queue-using-stacks	Java	Easy
234	palindrome-linked-list	Java		Easy
235	lowest-common-ancestor-of-a-binary-search-tree	Java	📝	Easy
236	lowest-common-ancestor-of-a-binary-tree	Java	📝	Medium
237	delete-node-in-a-linked-list	Java	📝	Easy
238	product-of-array-except-self	Java	📝	Medium
239	sliding-window-maximum	Java		Medium
240	search-a-2d-matrix-ii	Java	📝	Medium
242	valid-anagram	Java	📝	Easy
268	missing-number	Java	📝	Easy
279	perfect-squares	Java		Medium
283	move-zeroes	Java	📝	Easy
287	find-the-duplicate-number	Java	📝	Medium
289	game-of-life	Java	📝	Medium
295	find-median-from-data-stream	Java	📝	Hard
297	serialize-and-deserialize-binary-tree	Java	📝	Hard
300	longest-increasing-subsequence	Java	📝	Medium
303	range-sum-query-immutable	Java	📝	Easy
304	range-sum-query-2d-immutable	Java		Medium
309	best-time-to-buy-and-sell-stock-with-cooldown	Java		Medium
322	coin-change	Java	📝	Medium
326	power-of-three	Java	📝	Easy
328	odd-even-linked-list	Java	📝	Medium
329	longest-increasing-path-in-a-matrix	Java	📝	Hard
334	increasing-triplet-subsequence	Java		Medium
337	house-robber-iii	Java		Medium
338	counting-bits	Java	📝	Medium
341	flatten-nested-list-iterator	Java		Medium
344	reverse-string	Java		Easy
347	top-k-frequent-elements	Java	📝	Medium
350	intersection-of-two-arrays-ii	Java		Easy
371	sum-of-two-integers	Java		Easy
378	kth-smallest-element-in-a-sorted-matrix	Java		Medium
380	insert-delete-getrandom-o1	Java		Medium
384	shuffle-an-array	Java	📝	Medium
387	first-unique-character-in-a-string	Java	📝	Easy
395	longest-substring-with-at-least-k-repeating-characters	Java	Hard
406	queue-reconstruction-by-height	Java		Medium
412	fizz-buzz	Java	📝	Easy
416	partition-equal-subset-sum	Java		Medium
437	path-sum-iii	Java		Easy
438	find-all-anagrams-in-a-string	Java		Easy
443	string-compression	Java		Easy
445	add-two-numbers-ii	Java		Medium
448	find-all-numbers-disappeared-in-an-array	Java		Easy
454	4sum-ii	Java		Medium
461	hamming-distance	Java		Easy
476	number-complement	Java		Easy
485	max-consecutive-ones	Java		Easy
494	target-sum	Java	📝	Medium
520	detect-capital	Java		Easy
535	encode-and-decode-tinyurl	Java	📝	Medium
538	convert-bst-to-greater-tree	Java	📝	Easy
543	diameter-of-binary-tree	Java	📝	Easy
557	reverse-words-in-a-string-iii	Java	📝	Easy
557	permutation-in-string	Java	Medium
560	subarray-sum-equals-k	Java	📝	Medium
561	array-partition-i	Java	📝	Easy
566	reshape-the-matrix	Java	📝	Easy
572	subtree-of-another-tree	Java	Easy
581	shortest-unsorted-continuous-subarray	Java	📝	Easy
617	merge-two-binary-trees	Java	📝	Easy
628	maximum-product-of-three-numbers	Java	📝	Easy
637	average-of-levels-in-binary-tree	Java	📝	Easy
647	palindromic-substrings	Java	📝	Medium
653	two-sum-iv-input-is-a-bst	Java	📝	Easy
654	maximum-binary-tree	Java	📝	Medium
669	trim-a-binary-search-tree	Java	📝	Easy
674	longest-continuous-increasing-subsequence	Java	📝	Easy
717	1-bit-and-2-bit-characters	Java	📝	Easy
728	self-dividing-numbers	Java	📝	Easy
739	daily-temperatures	Java	📝	Medium
763	partition-labels	Java	Medium
771	jewels-and-stones	Java	Easy
774	maximum-depth-of-n-ary-tree	Java	📝	Easy
775	n-ary-tree-preorder-traversal	Java	📝	Easy
776	n-ary-tree-postorder-traversal	Java	📝	Easy
777	toeplitz-matrix	Java	📝	Easy
783	search-in-a-binary-search-tree	Java		Easy
784	insert-into-a-binary-search-tree	Java	📝	Medium
824	number-of-lines-to-write-string	Java	📝	Easy
825	max-increase-to-keep-city-skyline	Java	📝	Medium
829	subdomain-visit-count	Java	📝	Easy
832	binary-tree-pruning	Java	📝	Medium
841	shortest-distance-to-a-character	Java	📝	Easy
851	goat-latin	Java	📝	Easy
857	positions-of-large-groups	Java	📝	Easy
861	flipping-an-image	Java	📝	Easy
882	peak-index-in-a-mountain-array	Java	📝	Easy
898	transpose-matrix	Java	📝	Easy
904	leaf-similar-trees	Java	📝	Easy
908	middle-of-the-linked-list	Java	📝	Easy
919	projection-area-of-3d-shapes	Java	📝	Easy
924	fair-candy-swap	Java	📝	Easy
932	monotonic-array	Java	📝	Easy
933	increasing-order-search-tree	Java	📝	Easy
941	sort-array-by-parity	Java	📝	Easy
944	smallest-range-i	Java	📝	Easy
953	reverse-only-letters	Java	📝	Easy
958	sort-array-by-parity-ii	Java	📝	Easy
975	range-sum-of-bst	Java	📝	Easy
979	di-string-match	Java	📝	Easy
1001	n-repeated-element-in-size-2n-array	Java	📝	Easy
1005	univalued-binary-tree	Java	📝	Easy
1013	fibonacci-number	Java		Easy
1018	largest-perimeter-triangle	Java	📝	Easy
1019	squares-of-a-sorted-array	Java	📝	Easy
1027	sum-of-even-numbers-after-queries	Java	📝	Easy
1031	add-to-array-form-of-integer	Java	📝	Easy
1035	cousins-in-binary-tree	Java	📝	Easy
1041	available-captures-for-rook	Java		Easy
1044	find-common-characters	Java		Easy
1050	construct-binary-search-tree-from-preorder-traversal	Java	📝	Medium
1078	remove-outermost-parentheses	Java		Easy
1086	divisor-game	Java		Easy
1114	binary-search-tree-to-greater-sum-tree	Java		Medium
1127	last-stone-weight	Java		Easy
1128	remove-all-adjacent-duplicates-in-string	Java		Easy