✏️ Leetcode Solutions with Java

Update time: 2017-02-14 12:09:15

Auto created by leetcode_generate Usage

I have solved 105 / 482 problems while there are 85 problems still locked.

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
4	median-of-two-sorted-arrays			Hard
5	longest-palindromic-substring	Java	📝	Medium
6	zigzag-conversion	Java		Medium
7	reverse-integer	Java		Easy
8	string-to-integer-atoi	Java		Medium
9	palindrome-number			Easy
10	regular-expression-matching			Hard
11	container-with-most-water	Java	📝	Medium
12	integer-to-roman			Medium
13	roman-to-integer			Easy
14	longest-common-prefix	Java	📝	Easy
15	3sum	Java		Medium
16	3sum-closest	Java		Medium
17	letter-combinations-of-a-phone-number	Java		Medium
18	4sum	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			Medium
23	merge-k-sorted-lists	Java		Hard
24	swap-nodes-in-pairs			Medium
25	reverse-nodes-in-k-group	Java		Hard
26	remove-duplicates-from-sorted-array	Java	📝	Easy
27	remove-element	Java	📝	Easy
28	implement-strstr	Java		Easy
29	divide-two-integers	Java		Medium
30	substring-with-concatenation-of-all-words			Hard
31	next-permutation	Java	📝	Medium
32	longest-valid-parentheses		📝	Hard
33	search-in-rotated-sorted-array			Medium
34	search-for-a-range	Java		Medium
35	search-insert-position			Easy
36	valid-sudoku			Medium
37	sudoku-solver			Hard
38	count-and-say	Java		Easy
39	combination-sum			Medium
40	combination-sum-ii			Medium
41	first-missing-positive			Hard
42	trapping-rain-water			Hard
43	multiply-strings	Java		Medium
44	wildcard-matching			Hard
45	jump-game-ii			Hard
46	permutations	Java		Medium
47	permutations-ii	Java		Medium
48	rotate-image			Medium
49	anagrams	Java		Medium
50	powx-n	Java		Medium
51	n-queens			Hard
52	n-queens-ii			Hard
53	maximum-subarray			Easy
54	spiral-matrix	Java		Medium
55	jump-game		📝	Medium
56	merge-intervals	Java		Medium
57	insert-interval			Hard
58	length-of-last-word	Java		Easy
59	spiral-matrix-ii	Java		Medium
60	permutation-sequence			Medium
61	rotate-list	Java		Medium
62	unique-paths			Medium
63	unique-paths-ii			Medium
64	minimum-path-sum		📝	Medium
65	valid-number	Java		Hard
66	plus-one			Easy
67	add-binary	Java		Easy
68	text-justification	Java		Hard
69	sqrtx	Java		Easy
70	climbing-stairs		📝	Easy
71	simplify-path	Java		Medium
72	edit-distance			Hard
73	set-matrix-zeroes			Medium
74	search-a-2d-matrix			Medium
75	sort-colors	Java		Medium
76	minimum-window-substring			Hard
77	combinations	Java		Medium
78	subsets	Java		Medium
79	word-search	Java		Medium
80	remove-duplicates-from-sorted-array-ii	Java		Medium
81	search-in-rotated-sorted-array-ii			Medium
82	remove-duplicates-from-sorted-list-ii	Java		Medium
83	remove-duplicates-from-sorted-list		📝	Easy
84	largest-rectangle-in-histogram		📝	Hard
85	maximal-rectangle			Hard
86	partition-list	Java		Medium
87	scramble-string			Hard
88	merge-sorted-array	Java		Easy
89	gray-code			Medium
90	subsets-ii			Medium
91	decode-ways	Java		Medium
92	reverse-linked-list-ii	Java		Medium
93	restore-ip-addresses	Java		Medium
94	binary-tree-inorder-traversal	Java		Medium
95	unique-binary-search-trees-ii			Medium
96	unique-binary-search-trees			Medium
97	interleaving-string			Hard
98	validate-binary-search-tree			Medium
99	recover-binary-search-tree			Hard
100	same-tree			Easy
101	symmetric-tree		📝	Easy
102	binary-tree-level-order-traversal			Medium
103	binary-tree-zigzag-level-order-traversal			Medium
104	maximum-depth-of-binary-tree			Easy
105	construct-binary-tree-from-preorder-and-inorder-traversal	Java		Medium
106	construct-binary-tree-from-inorder-and-postorder-traversal			Medium
107	binary-tree-level-order-traversal-ii			Easy
108	convert-sorted-array-to-binary-search-tree			Easy
109	convert-sorted-list-to-binary-search-tree			Medium
110	balanced-binary-tree			Easy
111	minimum-depth-of-binary-tree			Easy
112	path-sum			Easy
113	path-sum-ii			Medium
114	flatten-binary-tree-to-linked-list			Medium
115	distinct-subsequences			Hard
116	populating-next-right-pointers-in-each-node			Medium
117	populating-next-right-pointers-in-each-node-ii			Medium
118	pascals-triangle			Easy
119	pascals-triangle-ii			Easy
120	triangle			Medium
121	best-time-to-buy-and-sell-stock	Java	📝	Easy
122	best-time-to-buy-and-sell-stock-ii	Java	📝	Easy
123	best-time-to-buy-and-sell-stock-iii	Java		Hard
124	binary-tree-maximum-path-sum			Hard
125	valid-palindrome	Java		Easy
126	word-ladder-ii			Hard
127	word-ladder			Medium
128	longest-consecutive-sequence			Hard
129	sum-root-to-leaf-numbers			Medium
130	surrounded-regions			Medium
131	palindrome-partitioning			Medium
132	palindrome-partitioning-ii			Hard
133	clone-graph	Java		Medium
134	gas-station			Medium
135	candy			Hard
136	single-number			Easy
137	single-number-ii			Medium
138	copy-list-with-random-pointer	Java		Medium
139	word-break		📝	Medium
140	word-break-ii		📝	Hard
141	linked-list-cycle	Java	📝	Easy
142	linked-list-cycle-ii	Java		Medium
143	reorder-list	Java		Medium
144	binary-tree-preorder-traversal			Medium
145	binary-tree-postorder-traversal	Java		Hard
146	lru-cache			Hard
147	insertion-sort-list			Medium
148	sort-list	Java		Medium
149	max-points-on-a-line			Hard
150	evaluate-reverse-polish-notation			Medium
151	reverse-words-in-a-string	Java		Medium
152	maximum-product-subarray	Java		Medium
153	find-minimum-in-rotated-sorted-array	Java		Medium
154	find-minimum-in-rotated-sorted-array-ii			Hard
155	min-stack			Easy
156	binary-tree-upside-down	🔒		Medium
157	read-n-characters-given-read4	🔒		Easy
158	read-n-characters-given-read4-ii-call-multiple-times	🔒		Hard
159	longest-substring-with-at-most-two-distinct-characters	🔒		Hard
160	intersection-of-two-linked-lists	Java	📝	Easy
161	one-edit-distance	🔒		Medium
162	find-peak-element			Medium
163	missing-ranges	🔒		Medium
164	maximum-gap		📝	Hard
165	compare-version-numbers	Java		Medium
166	fraction-to-recurring-decimal	Java	📝	Medium
167	two-sum-ii-input-array-is-sorted		📝	Easy
168	excel-sheet-column-title	Java		Easy
169	majority-element	Java		Easy
170	two-sum-iii-data-structure-design	🔒		Easy
171	excel-sheet-column-number			Easy
172	factorial-trailing-zeroes			Easy
173	binary-search-tree-iterator			Medium
174	dungeon-game			Hard
179	largest-number			Medium
186	reverse-words-in-a-string-ii	🔒		Medium
187	repeated-dna-sequences			Medium
188	best-time-to-buy-and-sell-stock-iv	Java		Hard
189	rotate-array	Java	📝	Easy
190	reverse-bits			Easy
191	number-of-1-bits		📝	Easy
198	house-robber		📝	Easy
199	binary-tree-right-side-view			Medium
200	number-of-islands			Medium
201	bitwise-and-of-numbers-range			Medium
202	happy-number			Easy
203	remove-linked-list-elements	Java		Easy
204	count-primes	Java		Easy
205	isomorphic-strings	Java		Easy
206	reverse-linked-list	Java	📝	Easy
207	course-schedule			Medium
208	implement-trie-prefix-tree		📝	Medium
209	minimum-size-subarray-sum	Java		Medium
210	course-schedule-ii			Medium
211	add-and-search-word-data-structure-design			Medium
212	word-search-ii			Hard
213	house-robber-ii			Medium
214	shortest-palindrome			Hard
215	kth-largest-element-in-an-array	Java		Medium
216	combination-sum-iii			Medium
217	contains-duplicate	Java	📝	Easy
218	the-skyline-problem			Hard
219	contains-duplicate-ii	Java	📝	Easy
220	contains-duplicate-iii		📝	Medium
221	maximal-square		📝	Medium
222	count-complete-tree-nodes			Medium
223	rectangle-area			Medium
224	basic-calculator			Hard
225	implement-stack-using-queues		📝	Easy
226	invert-binary-tree		📝	Easy
227	basic-calculator-ii	Java		Medium
228	summary-ranges	Java	📝	Medium
229	majority-element-ii	Java		Medium
230	kth-smallest-element-in-a-bst			Medium
231	power-of-two			Easy
232	implement-queue-using-stacks		📝	Easy
233	number-of-digit-one	Java		Hard
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		📝	Easy
238	product-of-array-except-self			Medium
239	sliding-window-maximum			Hard
240	search-a-2d-matrix-ii			Medium
241	different-ways-to-add-parentheses			Medium
242	valid-anagram		📝	Easy
243	shortest-word-distance	🔒	📝	Easy
244	shortest-word-distance-ii	🔒		Medium
245	shortest-word-distance-iii	🔒		Medium
246	strobogrammatic-number	🔒		Easy
247	strobogrammatic-number-ii	🔒		Medium
248	strobogrammatic-number-iii	🔒		Hard
249	group-shifted-strings	🔒		Medium
250	count-univalue-subtrees	🔒		Medium
251	flatten-2d-vector	🔒		Medium
252	meeting-rooms	🔒	📝	Easy
253	meeting-rooms-ii	🔒		Medium
254	factor-combinations	🔒		Medium
255	verify-preorder-sequence-in-binary-search-tree	🔒		Medium
256	paint-house	🔒		Easy
257	binary-tree-paths			Easy
258	add-digits			Easy
259	3sum-smaller	🔒	📝	Medium
260	single-number-iii			Medium
261	graph-valid-tree	🔒		Medium
263	ugly-number			Easy
264	ugly-number-ii			Medium
265	paint-house-ii	🔒		Hard
266	palindrome-permutation	🔒		Easy
267	palindrome-permutation-ii	🔒		Medium
268	missing-number	Java		Easy
269	alien-dictionary	🔒		Hard
270	closest-binary-search-tree-value	🔒		Easy
271	encode-and-decode-strings	🔒		Medium
272	closest-binary-search-tree-value-ii	🔒		Hard
273	integer-to-english-words			Hard
274	h-index	Java	📝	Medium
275	h-index-ii			Medium
276	paint-fence	🔒		Easy
277	find-the-celebrity	🔒		Medium
278	first-bad-version	Java	📝	Easy
279	perfect-squares			Medium
280	wiggle-sort	🔒	📝	Medium
281	zigzag-iterator	🔒		Medium
282	expression-add-operators	Java		Hard
283	move-zeroes		📝	Easy
284	peeking-iterator			Medium
285	inorder-successor-in-bst	🔒		Medium
286	walls-and-gates	🔒	📝	Medium
287	find-the-duplicate-number	Java		Medium
288	unique-word-abbreviation	🔒	📝	Medium
289	game-of-life			Medium
290	word-pattern	Java		Easy
291	word-pattern-ii	🔒		Hard
292	nim-game		📝	Easy
293	flip-game	🔒		Easy
294	flip-game-ii	🔒		Medium
295	find-median-from-data-stream		📝	Hard
296	best-meeting-point	🔒	📝	Hard
297	serialize-and-deserialize-binary-tree			Hard
298	binary-tree-longest-consecutive-sequence	🔒	📝	Medium
299	bulls-and-cows			Medium
300	longest-increasing-subsequence		📝	Medium
301	remove-invalid-parentheses			Hard
302	smallest-rectangle-enclosing-black-pixels	🔒	📝	Hard
303	range-sum-query-immutable		📝	Easy
304	range-sum-query-2d-immutable		📝	Medium
305	number-of-islands-ii	🔒		Hard
306	additive-number			Medium
307	range-sum-query-mutable		📝	Medium
308	range-sum-query-2d-mutable	🔒		Hard
309	best-time-to-buy-and-sell-stock-with-cooldown			Medium
310	minimum-height-trees			Medium
311	sparse-matrix-multiplication	🔒		Medium
312	burst-balloons			Hard
313	super-ugly-number			Medium
314	binary-tree-vertical-order-traversal	🔒		Medium
315	count-of-smaller-numbers-after-self			Hard
316	remove-duplicate-letters			Hard
317	shortest-distance-from-all-buildings	🔒		Hard
318	maximum-product-of-word-lengths			Medium
319	bulb-switcher			Medium
320	generalized-abbreviation	🔒	📝	Medium
321	create-maximum-number			Hard
322	coin-change		📝	Medium
323	number-of-connected-components-in-an-undirected-graph	🔒		Medium
324	wiggle-sort-ii			Medium
325	maximum-size-subarray-sum-equals-k	🔒		Medium
326	power-of-three		📝	Easy
327	count-of-range-sum			Hard
328	odd-even-linked-list		📝	Medium
329	longest-increasing-path-in-a-matrix		📝	Hard
330	patching-array		📝	Hard
331	verify-preorder-serialization-of-a-binary-tree			Medium
332	reconstruct-itinerary			Medium
333	largest-bst-subtree	🔒		Medium
334	increasing-triplet-subsequence			Medium
335	self-crossing			Hard
336	palindrome-pairs			Hard
337	house-robber-iii			Medium
338	counting-bits		📝	Medium
339	nested-list-weight-sum	🔒	📝	Easy
340	longest-substring-with-at-most-k-distinct-characters	🔒		Hard
341	flatten-nested-list-iterator			Medium
342	power-of-four			Easy
343	integer-break			Medium
344	reverse-string			Easy
345	reverse-vowels-of-a-string			Easy
346	moving-average-from-data-stream	🔒		Easy
347	top-k-frequent-elements			Medium
348	design-tic-tac-toe	🔒		Medium
349	intersection-of-two-arrays			Easy
350	intersection-of-two-arrays-ii			Easy
351	android-unlock-patterns	🔒	📝	Medium
352	data-stream-as-disjoint-intervals			Hard
353	design-snake-game	🔒		Medium
354	russian-doll-envelopes			Hard
355	design-twitter	Java		Medium
356	line-reflection	🔒		Medium
357	count-numbers-with-unique-digits			Medium
358	rearrange-string-k-distance-apart	🔒		Hard
359	logger-rate-limiter	🔒		Easy
360	sort-transformed-array	🔒		Medium
361	bomb-enemy	🔒		Medium
362	design-hit-counter	🔒		Medium
363	max-sum-of-sub-matrix-no-larger-than-k			Hard
364	nested-list-weight-sum-ii	🔒		Medium
365	water-and-jug-problem	Java		Medium
366	find-leaves-of-binary-tree	🔒		Medium
367	valid-perfect-square			Easy
368	largest-divisible-subset			Medium
369	plus-one-linked-list	🔒		Medium
370	range-addition	🔒	📝	Medium
371	sum-of-two-integers			Easy
372	super-pow			Medium
373	find-k-pairs-with-smallest-sums			Medium
374	guess-number-higher-or-lower		📝	Easy
375	guess-number-higher-or-lower-ii		📝	Medium
376	wiggle-subsequence		📝	Medium
377	combination-sum-iv			Medium
378	kth-smallest-element-in-a-sorted-matrix			Medium
379	design-phone-directory	🔒		Medium
380	insert-delete-getrandom-o1			Medium
381	insert-delete-getrandom-o1-duplicates-allowed			Hard
382	linked-list-random-node			Medium
383	ransom-note			Easy
384	shuffle-an-array			Medium
385	mini-parser	Java		Medium
386	lexicographical-numbers			Medium
387	first-unique-character-in-a-string			Easy
388	longest-absolute-file-path			Medium
389	find-the-difference			Easy
390	elimination-game			Medium
391	perfect-rectangle			Hard
392	is-subsequence			Medium
393	utf-8-validation			Medium
394	decode-string			Medium
395	longest-substring-with-at-least-k-repeating-characters			Medium
396	rotate-function			Medium
397	integer-replacement	Java		Medium
398	random-pick-index			Medium
399	evaluate-division			Medium
400	nth-digit			Easy
401	binary-watch			Easy
402	remove-k-digits			Medium
403	frog-jump		📝	Hard
404	sum-of-left-leaves			Easy
405	convert-a-number-to-hexadecimal			Easy
406	queue-reconstruction-by-height			Medium
407	trapping-rain-water-ii			Hard
408	valid-word-abbreviation	🔒		Easy
409	longest-palindrome			Easy
410	split-array-largest-sum			Hard
411	minimum-unique-word-abbreviation	🔒		Hard
412	fizz-buzz			Easy
413	arithmetic-slices			Medium
414	third-maximum-number	Java		Easy
415	add-strings			Easy
416	partition-equal-subset-sum			Medium
417	pacific-atlantic-water-flow			Medium
418	sentence-screen-fitting	🔒		Medium
419	battleships-in-a-board	Java		Medium
420	strong-password-checker			Hard
421	maximum-xor-of-two-numbers-in-an-array			Medium
422	valid-word-square	🔒		Easy
423	reconstruct-original-digits-from-english			Medium
424	longest-repeating-character-replacement			Medium
425	word-squares	🔒		Hard
432	all-oone-data-structure			Hard
434	number-of-segments-in-a-string			Easy
435	non-overlapping-intervals		📝	Medium
436	find-right-interval			Medium
437	path-sum-iii			Easy
438	find-all-anagrams-in-a-string			Easy
439	ternary-expression-parser	🔒		Medium
440	k-th-smallest-in-lexicographical-order			Hard
441	arranging-coins	Java		Easy
442	find-all-duplicates-in-an-array			Medium
444	sequence-reconstruction	🔒		Medium
445	add-two-numbers-ii			Medium
446	arithmetic-slices-ii-subsequence			Hard
447	number-of-boomerangs			Easy
448	find-all-numbers-disappeared-in-an-array			Easy
449	serialize-and-deserialize-bst	Java		Medium
450	delete-node-in-a-bst			Medium
451	sort-characters-by-frequency			Medium
452	minimum-number-of-arrows-to-burst-balloons			Medium
453	minimum-moves-to-equal-array-elements		📝	Easy
454	4sum-ii	Java		Medium
455	assign-cookies			Easy
456	132-pattern			Medium
459	repeated-substring-pattern			Easy
460	lfu-cache			Hard
461	hamming-distance			Easy
462	minimum-moves-to-equal-array-elements-ii			Medium
463	island-perimeter			Easy
464	can-i-win			Medium
465	optimal-account-balancing	🔒		Hard
466	count-the-repetitions			Hard
467	unique-substrings-in-wraparound-string			Medium
468	validate-ip-address	Java		Medium
469	convex-polygon	🔒		Medium
471	encode-string-with-shortest-length	🔒		Hard
472	concatenated-words			Hard
473	matchsticks-to-square			Medium
474	ones-and-zeroes			Medium
475	heaters			Easy
476	number-complement			Easy
477	total-hamming-distance		📝	Medium
480	sliding-window-median		📝	Hard
481	magical-string			Medium
482	license-key-formatting			Medium
483	smallest-good-base			Hard
484	find-permutation	🔒		Medium
485	max-consecutive-ones			Easy
486	predict-the-winner			Medium
487	max-consecutive-ones-ii	🔒		Medium
488	zuma-game			Hard
490	the-maze	🔒		Medium
491	increasing-subsequences			Medium
492	construct-the-rectangle			Easy
493	reverse-pairs			Hard
494	target-sum			Medium
495	teemo-attacking			Medium
496	next-greater-element-i			Easy
498	diagonal-traverse			Medium
499	the-maze-iii	🔒		Hard
500	keyboard-row			Easy
501	find-mode-in-binary-search-tree			Easy
502	ipo			Hard
503	next-greater-element-ii			Medium
504	base-7			Easy
505	the-maze-ii	🔒		Medium
506	relative-ranks			Easy
508	most-frequent-subtree-sum			Medium
513	find-bottom-left-tree-value			Medium
515	find-largest-value-in-each-tree-row			Medium
516	longest-palindromic-subsequence			Medium