LeetCode

LeetCode solutions gives some thoughts on selected problems.

Solved 206/215 problems.

Database

See database.md

Algorithms

#	Title	Solution
231	Power of Two	power-of-two.cc
230	Kth Smallest Element in a BST	kth-smallest-element-in-a-bst.cc
229	Majority Element II	majority-element-ii.cc
228	Summary Ranges	summary-ranges.cc
227	Basic Calculator II	basic-calculator-ii.cc
226	Invert Binary Tree	invert-binary-tree.cc
225	Implement Stack using Queues	implement-stack-using-queues.cc
224	Basic Calculator	basic-calculator.cc
223	Rectangle Area	rectangle-area.cc
222	Count Complete Tree Nodes	count-complete-tree-nodes.cc
221	Maximal Square	maximal-square.cc
220	Contains Duplicate III	contains-duplicate-iii.cc
219	Contains Duplicate II	contains-duplicate-ii.cc
218	The Skyline Problem	the-skyline-problem.cc
217	Contains Duplicate	contains-duplicate.cc
216	Combination Sum III	combination-sum-iii.cc
215	Kth Largest Element in an Array	kth-largest-element-in-an-array.cc
214	Shortest Palindrome	shortest-palindrome.cc
213	House Robber II	house-robber-ii.cc
212	Word Search II	word-search-ii.cc
211	Add and Search Word - Data structure design	add-and-search-word-data-structure-design.cc
210	Course Schedule II	course-schedule-ii.cc
209	Minimum Size Subarray Sum	minimum-size-subarray-sum.cc
208	Implement Trie (Prefix Tree)	implement-trie-prefix-tree.cc
207	Course Schedule	course-schedule.cc
206	Reverse Linked List	reverse-linked-list.cc
205	Isomorphic Strings	isomorphic-strings.cc
204	Count Primes	count-primes.cc
203	Remove Linked List Elements	remove-linked-list-elements.cc
202	Happy Number	happy-number.cc
201	Bitwise AND of Numbers Range	bitwise-and-of-numbers-range.cc
200	Number of Islands	number-of-islands.cc
199	Binary Tree Right Side View	binary-tree-right-side-view.cc
198	House Robber	house-robber.cc
191	Number of 1 Bits	number-of-1-bits.cc
190	Reverse Bits	reverse-bits.cc
189	Rotate Array	rotate-array.cc
188	Best Time to Buy and Sell Stock IV	best-time-to-buy-and-sell-stock-iv.cc
187	Repeated DNA Sequences	repeated-dna-sequences.cc
186	Reverse Words in a String II	reverse-words-in-a-string-ii.cc
179	Largest Number	largest-number.cc
174	Dungeon Game	dungeon-game.cc
173	Binary Search Tree Iterator	binary-search-tree-iterator.cc
172	Factorial Trailing Zeroes	factorial-trailing-zeroes.cc
171	Excel Sheet Column Number	excel-sheet-column-number.cc
170	Two Sum III - Data structure design	two-sum-iii-data-structure-design.cc
169	Majority Element	majority-element.cc
168	Excel Sheet Column Title	excel-sheet-column-title.cc
167	Two Sum II - Input array is sorted	two-sum-ii-input-array-is-sorted.cc
166	Fraction to Recurring Decimal	fraction-to-recurring-decimal.cc
165	Compare Version Numbers	compare-version-numbers.cc
164	Maximum Gap	maximum-gap.cc
163	Missing Ranges	missing-ranges.cc
162	Find Peak Element	find-peak-element.cc
161	One Edit Distance	one-edit-distance.cc
160	Intersection of Two Linked Lists	intersection-of-two-linked-lists.cc
159	Longest Substring with At Most Two Distinct Characters	longest-substring-with-at-most-two-distinct-characters.cc
158	Read N Characters Given Read4 II - Call multiple times	read-n-characters-given-read4-ii-call-multiple-times.cc
157	Read N Characters Given Read4	read-n-characters-given-read4.cc
156	Binary Tree Upside Down	binary-tree-upside-down.cc
155	Min Stack	min-stack.cc
154	Find Minimum in Rotated Sorted Array II	find-minimum-in-rotated-sorted-array-ii.cc
153	Find Minimum in Rotated Sorted Array	find-minimum-in-rotated-sorted-array.cc
152	Maximum Product Subarray	maximum-product-subarray.cc
151	Reverse Words in a String	reverse-words-in-a-string.cc
150	Evaluate Reverse Polish Notation	evaluate-reverse-polish-notation.cc
149	Max Points on a Line	max-points-on-a-line.cc
148	Sort List	sort-list.cc
147	Insertion Sort List	insertion-sort-list.cc
146	LRU Cache	lru-cache.cc
145	Binary Tree Postorder Traversal	binary-tree-postorder-traversal.cc
144	Binary Tree Preorder Traversal	binary-tree-preorder-traversal.cc
143	Reorder List	reorder-list.cc
142	Linked List Cycle II	linked-list-cycle-ii.cc
141	Linked List Cycle	linked-list-cycle.cc
140	Word Break II	word-break-ii.cc
139	Word Break	word-break.cc
138	Copy List with Random Pointer	copy-list-with-random-pointer.cc
137	Single Number II	single-number-ii.cc
136	Single Number	single-number.cc
135	Candy	candy.cc
134	Gas Station	gas-station.cc
133	Clone Graph	clone-graph.cc
132	Palindrome Partitioning II	palindrome-partitioning-ii.cc
131	Palindrome Partitioning	palindrome-partitioning.cc
130	Surrounded Regions	surrounded-regions.cc
129	Sum Root to Leaf Numbers	sum-root-to-leaf-numbers.cc
128	Longest Consecutive Sequence	longest-consecutive-sequence.cc
127	Word Ladder	word-ladder.cc
126	Word Ladder II	word-ladder-ii.cc
125	Valid Palindrome	valid-palindrome.cc
124	Binary Tree Maximum Path Sum	binary-tree-maximum-path-sum.cc
123	Best Time to Buy and Sell Stock III	best-time-to-buy-and-sell-stock-iii.cc
122	Best Time to Buy and Sell Stock II	best-time-to-buy-and-sell-stock-ii.cc
121	Best Time to Buy and Sell Stock	best-time-to-buy-and-sell-stock.cc
120	Triangle	triangle.cc
119	Pascal's Triangle II	pascals-triangle-ii.cc
118	Pascal's Triangle	pascals-triangle.cc
117	Populating Next Right Pointers in Each Node II	populating-next-right-pointers-in-each-node-ii.cc
116	Populating Next Right Pointers in Each Node	populating-next-right-pointers-in-each-node.cc
115	Distinct Subsequences	distinct-subsequences.cc
114	Flatten Binary Tree to Linked List	flatten-binary-tree-to-linked-list.cc
113	Path Sum II	path-sum-ii.cc
112	Path Sum	path-sum.cc
111	Minimum Depth of Binary Tree	minimum-depth-of-binary-tree.cc
110	Balanced Binary Tree	balanced-binary-tree.cc
109	Convert Sorted List to Binary Search Tree	convert-sorted-list-to-binary-search-tree.cc
108	Convert Sorted Array to Binary Search Tree	convert-sorted-array-to-binary-search-tree.cc
107	Binary Tree Level Order Traversal II	binary-tree-level-order-traversal-ii.cc
106	Construct Binary Tree from Inorder and Postorder Traversal	construct-binary-tree-from-inorder-and-postorder-traversal.cc
105	Construct Binary Tree from Preorder and Inorder Traversal	construct-binary-tree-from-preorder-and-inorder-traversal.cc
104	Maximum Depth of Binary Tree	maximum-depth-of-binary-tree.cc
103	Binary Tree Zigzag Level Order Traversal	binary-tree-zigzag-level-order-traversal.cc
102	Binary Tree Level Order Traversal	binary-tree-level-order-traversal.cc
101	Symmetric Tree	symmetric-tree.cc
100	Same Tree	same-tree.cc
99	Recover Binary Search Tree	recover-binary-search-tree.cc
98	Validate Binary Search Tree	validate-binary-search-tree.cc
97	Interleaving String	interleaving-string.cc
96	Unique Binary Search Trees	unique-binary-search-trees.cc
95	Unique Binary Search Trees II	unique-binary-search-trees-ii.cc
94	Binary Tree Inorder Traversal	binary-tree-inorder-traversal.cc
93	Restore IP Addresses	restore-ip-addresses.cc
92	Reverse Linked List II	reverse-linked-list-ii.cc
91	Decode Ways	decode-ways.cc
90	Subsets II	subsets-ii.cc
89	Gray Code	gray-code.cc
88	Merge Sorted Array	merge-sorted-array.cc
87	Scramble String	scramble-string.cc
86	Partition List	partition-list.cc
85	Maximal Rectangle	maximal-rectangle.cc
84	Largest Rectangle in Histogram	largest-rectangle-in-histogram.cc
83	Remove Duplicates from Sorted List	remove-duplicates-from-sorted-list.cc
82	Remove Duplicates from Sorted List II	remove-duplicates-from-sorted-list-ii.cc
81	Search in Rotated Sorted Array II	search-in-rotated-sorted-array-ii.cc
80	Remove Duplicates from Sorted Array II	remove-duplicates-from-sorted-array-ii.cc
79	Word Search	word-search.cc
78	Subsets	subsets.cc
77	Combinations	combinations.cc
76	Minimum Window Substring	minimum-window-substring.cc
75	Sort Colors	sort-colors.cc
74	Search a 2D Matrix	search-a-2d-matrix.cc
73	Set Matrix Zeroes	set-matrix-zeroes.cc
72	Edit Distance	edit-distance.cc
71	Simplify Path	simplify-path.cc
70	Climbing Stairs	climbing-stairs.cc
69	Sqrt(x)	sqrtx.cc
68	Text Justification	text-justification.cc
67	Add Binary	add-binary.cc
66	Plus One	plus-one.cc
65	Valid Number	valid-number.cc
64	Minimum Path Sum	minimum-path-sum.cc
63	Unique Paths II	unique-paths-ii.cc
62	Unique Paths	unique-paths.cc
61	Rotate List	rotate-list.cc
60	Permutation Sequence	permutation-sequence.cc
59	Spiral Matrix II	spiral-matrix-ii.cc
58	Length of Last Word	length-of-last-word.cc
57	Insert Interval	insert-interval.cc
56	Merge Intervals	merge-intervals.cc
55	Jump Game	jump-game.cc
54	Spiral Matrix	spiral-matrix.cc
53	Maximum Subarray	maximum-subarray.cc
52	N-Queens II	n-queens-ii.cc
51	N-Queens	n-queens.cc
50	Pow(x, n)	powx-n.cc
49	Anagrams	anagrams.cc
48	Rotate Image	rotate-image.cc
47	Permutations II	permutations-ii.cc
46	Permutations	permutations.cc
45	Jump Game II	jump-game-ii.cc
44	Wildcard Matching	wildcard-matching.cc
43	Multiply Strings	multiply-strings.cc
42	Trapping Rain Water	trapping-rain-water.cc
41	First Missing Positive	first-missing-positive.cc
40	Combination Sum II	combination-sum-ii.cc
39	Combination Sum	combination-sum.cc
38	Count and Say	count-and-say.cc
37	Sudoku Solver	sudoku-solver.cc
36	Valid Sudoku	valid-sudoku.cc
35	Search Insert Position	search-insert-position.cc
34	Search for a Range	search-for-a-range.cc
33	Search in Rotated Sorted Array	search-in-rotated-sorted-array.cc
32	Longest Valid Parentheses	longest-valid-parentheses.cc
31	Next Permutation	next-permutation.cc
30	Substring with Concatenation of All Words	substring-with-concatenation-of-all-words.cc
29	Divide Two Integers	divide-two-integers.cc
28	Implement strStr()	implement-strstr.cc
27	Remove Element	remove-element.cc
26	Remove Duplicates from Sorted Array	remove-duplicates-from-sorted-array.cc
25	Reverse Nodes in k-Group	reverse-nodes-in-k-group.cc
24	Swap Nodes in Pairs	swap-nodes-in-pairs.cc
23	Merge k Sorted Lists	merge-k-sorted-lists.cc
22	Generate Parentheses	generate-parentheses.cc
21	Merge Two Sorted Lists	merge-two-sorted-lists.cc
20	Valid Parentheses	valid-parentheses.cc
19	Remove Nth Node From End of List	remove-nth-node-from-end-of-list.cc
18	4Sum	4sum.cc
17	Letter Combinations of a Phone Number	letter-combinations-of-a-phone-number.cc
16	3Sum Closest	3sum-closest.cc
15	3Sum	3sum.cc
14	Longest Common Prefix	longest-common-prefix.cc
13	Roman to Integer	roman-to-integer.cc
12	Integer to Roman	integer-to-roman.cc
11	Container With Most Water	container-with-most-water.cc
10	Regular Expression Matching	regular-expression-matching.cc
9	Palindrome Number	palindrome-number.cc
8	String to Integer (atoi)	string-to-integer-atoi.cc
7	Reverse Integer	reverse-integer.cc
6	ZigZag Conversion	zigzag-conversion.cc
5	Longest Palindromic Substring	longest-palindromic-substring.cc
4	Median of Two Sorted Arrays	median-of-two-sorted-arrays.cc
3	Longest Substring Without Repeating Characters	longest-substring-without-repeating-characters.cc
2	Add Two Numbers	add-two-numbers.cc
1	Two Sum	two-sum.cc