My solutions to Leetcode

I will put my solutions to Leetcode Problems in this repo. Every problem will be solved in C++; part of the problems will be solved in Java also. I will try my best to support more language in the future :)

Please feel free to contact me if you have any questions with this repo:)

email: [email protected]

---

大家好，欢迎大家来到我的 Leetcode 题解代码仓。在这个代码仓中，近乎每一个问题都会使用多种方式进行解决，同时标注了简明的算法思想，时间复杂度和空间复杂度。所有问题都会使用C++进行解决，各别问题支持Java语言和Python语言。

由于 Leetcode 如今已经问题量巨大，所以很多同学可能会刷起来毫无头绪。推荐大家可以使用 Leetcode 在2017年底推出的 Leetcode Explore，这个模块分门别类地整理了Leetcode上的问题，是一个很好的刷 Leetcode 的指引。Leetcode Explore模块上的题解，可以参考我的代码仓：Play Leetcode Explore

如果对代码仓有任何问题，欢迎联系我：）

个人网站：liuyubobobo.com

电子邮件：[email protected]

微博: 刘宇波bobo http://weibo.com/liuyubobobo

知乎: 刘宇波 http://www.zhihu.com/people/liuyubobobo

知乎专栏：是不是很酷 https://zhuanlan.zhihu.com/liuyubobobo

个人公众号：是不是很酷：）

其他相关代码仓

• 《算法与数据结构》课程, 代码仓: Play-with-Algorithms

• 《玩转算法面试》课程, 代码仓: Play-with-Algorithm-Interview

• 《看得见的算法》课程, 代码仓: Play-with-Algorithm-Visualization

• 《玩转数据结构》课程, 代码仓: Play-with-Data-Structures

• LeetCode Explore题解代码仓：Play Leetcode Explore （注：以C++实现为主）

  • Leetcode Explore 是 Leetcode 在2017年底上线的新模块，分门别类地整理了Leetcode上的问题。如果刷Leetcode一时不知从哪里下手，可以从Leetcode Explore为指引开始：）

Problems

ID	Problem	Official Solution	C++	Java	Python
001	Two Sum	solution	C++	Java
002	Add Two Numbers	solution	C++
003	Longest-Substring-Without-Repeating-Characters	solution	C++	Java
007	Reverse Integer	solution	C++
011	Container With Most Water	solution	C++
012	Integer to Roman	[无]	C++
013	Roman to Integer	[无]	C++
014	Longest Common Prefix	[无]	C++
015	3Sum	[无]	C++
016	3Sum Closest	[无]	C++
017	Letter Combinations of a Phone Number	solution	C++	Java
018	4Sum	[无]	C++
019	Remove Nth Node From End of List	solution	C++	Java
020	Valid Parentheses	solution	C++	Java
021	Merge Two Sorted Lists	solution	C++
022	Generate Parentheses	solution	C++
023	Merge k Sorted Lists	solution	C++
024	Swap Nodes in Pairs	[无]	C++	Java
025	Reverse Nodes in k-Group	[无]	C++
026	Remove Duplicates from Sorted Array	solution	C++
027	Remove Element	solution	C++
028	Implement strStr()	[无] [缺：KMP等高级字符串匹配算法]	C++
033	Search in Rotated Sorted Array	solution	C++
034	Search for a Range	solution	C++
036	Valid Sudoku	solution	C++
037	Sudoku Solver	[无] [缺：Dancing Links]	C++
038	Count and Say	[无]	C++
039	Combination Sum	[无]	C++
040	Combination Sum II	[无]	C++
041	First Missing Positive	solution	C++
042	Trapping Rain Water	solution	C++
046	Permutations	solution [缺：排列算法整理]	C++	Java
047	Permutations II	[无]	C++
048	Rotate Image	solution	C++
049	Group Anagrams	solution	C++
050	Pow(x, n)	[无]	C++
051	N-Queens	[缺：N皇后问题整理]	C++	Java
052	N-Queens II	solution [缺：N皇后问题整理]	C++
054	Spiral Matrix	solution	C++
056	Merge Intervals	solution	C++
059	Spiral Matrix II	[无]	C++
061	Rotate List	[无]	C++
063	Unique Paths II	solution	C++
064	Minimum Path Sum	solution	C++	Java
066	Plus One	[无]	C++
067	Add Binary	[无]	C++
069	Sqrt(x)	[无]	C++
070	Climbing Stairs	solution	C++	Java
072	Edit Distance	solution	C++
073	Set Matrix Zeroes	solution	C++
075	Sort Colors	[无]	C++	Java
076	Minimum Window Substring	solution	C++
077	Combinations	[缺：组合算法整理]	C++	Java
079	Word Search	[无]	C++	Java
080	Remove Duplicates from Sorted Array II	[无]	C++
082	Remove Duplicates from Sorted List II	[无]	C++
086	Partition List	solution	C++
087	Scramble String	[无]	C++
088	Merge Sorted Array	solution	C++
092	Reverse Linked List II	solution	C++
093	Restore IP Addresses	solution	C++
094	Binary Tree Inorder Traversal	solution	C++	Java
095	Unique Binary Search Trees II	solution	C++
096	Unique Binary Search Trees	solution	C++
098	Validate Binary Search Tree	solution	C++	Java
099	Recover Binary Search Tree	[无]		Java
100	Same Tree	[无]	C++
101	Symmetric Tree	solution	C++
102	Binary Tree Level Order Traversal	[无]	C++	Java
104	Maximum Depth of Binary Tree	solution	C++	Java
105	Construct Binary Tree from Preorder and Inorder Traversal	solution	C++
106	Construct Binary Tree from Inorder and Postorder Traversal	[无]	C++
107	Binary Tree Level Order Traversal II	[无]	C++
108	Convert Sorted Array to Binary Search Tree	[无]	C++
109	Convert Sorted List to Binary Search Tree	solution	C++
111	Minimum Depth of Binary Tree	solution	C++
112	Path Sum	solution	C++	Java
113	Path Sum II	[无]	C++
115	Distinct Subsequences	[无]	C++	Java
116	Populating Next Right Pointers in Each Node	[无]	C++
117	Populating Next Right Pointers in Each Node II	[无]	C++
118	Pascal's Triangle	solution	C++
119	Pascal's Triangle II	[无]	C++
120	Triangle	[无]	C++
121	Best Time to Buy and Sell Stock		C++
122	Best Time to Buy and Sell Stock II		C++
123	Best Time to Buy and Sell Stock III		C++
125	Valid Palindrome	[无]	C++
126	Word Ladder II	[无] [缺：双端搜索]	C++
127	Word Ladder	[无]	C++	Java
128	Longest Consecutive Sequence		C++
129	Sum Root to Leaf Numbers	[无]	C++
130	Surrounded Regions	[无]	C++
133	Clone Graph	[无]	C++
135	Candy	solution [缺：O(1)空间算法]	C++
136	Single Number	solution	C++
138	Copy List with Random Pointer	solution	C++
141	Linked List Cycle	solution	C++
142	Linked List Cycle II	solution	C++
144	Binary Tree Preorder Traversal	solution	C++	Java
145	Binary Tree Postorder Traversal	solution	C++	Java
147	Insertion Sort List	C++
148	Sort List	[无]	C++
149	Max Points on a Line	solution	C++
150	Evaluate Reverse Polish Notation	[无]	C++
151	Reverse Words in a String	[无]	C++
153	Find Minimum in Rotated Sorted Array	solution	C++
155	Min Stack	[无]	C++
159	Longest Substring with At Most Two Distinct Characters	solution	C++
160	Intersection of Two Linked Lists	solution	C++
161	One Edit Distance	solution	C++
167	Two Sum II - Input array is sorted	solution	C++	Java
169	Majority Element	solution	C++
170	Two Sum III - Data structure design	[无]	C++
171	Excel Sheet Column Number	[无]	C++
173	Binary Search Tree Iterator	[无] [缺：Morris遍历]	C++
186	Reverse Words in a String II	[无]	C++
188	Best-Time-to-Buy-and-Sell-Stock-IV		C++
189	Rotate Array	solution	C++
191	Number of 1 Bits	solution	C++
198	House Robber	solution	C++	Java
200	Number of Islands	solution	C++	Java
202	Happy Number	[无]	C++
203	Remove Linked List Elements	[无]	C++	Java
205	Isomorphic Strings	[无]	C++
206	Reverse Linked List	solution	C++	Java
207	Course Schedule	[无]	C++
208	Implement Trie (Prefix Tree)	solution	C++
209	Minimum Size Subarray Sum	solution	C++	Java
210	Course Schedule II	solution	C++
211	Add and Search Word - Data structure design	[无]	C++
212	Word Search II	[无]	C++
213	House Robber II	[无]	C++
215	Kth Largest Element in an Array	solution	C++
216	Combination Sum III	[无]	C++
217	Contains Duplicate	[无]	C++
218	The Skyline Problem		C++
219	Contains Duplicate II	solution	C++	Java
220	Contains Duplicate III	solution	C++	Java
222	Count Complete Tree Nodes	[无]	C++
224	Basic Calculator	[无]	C++
225	Implement Stack using Queues	solution	C++
226	Invert Binary Tree	solution	C++	Java
227	Basic Calculator II	[无]	C++
230	Kth Smallest Element in a BST	[无]	C++
232	Implement Queue using Stacks	solution	C++
234	Palindrome Linked List	[无]	C++
235	Lowest Common Ancestor of a Binary Search Tree	solution	C++	Java
236	Lowest Common Ancestor of a Binary Tree	solution [缺：非递归解法；LCA问题总结]	C++
237	Delete Node in a Linked List	solution	C++	Java
239	Sliding Window Maximum	[无]	C++
242	Valid Anagram	solution	C++
243	Shortest Word Distance	solution	C++
244	Shortest Word Distance II	solution	C++
245	Shortest Word Distance III	[无]	C++
249	Group Shifted Strings	[无]	C++
250	Count Univalue Subtrees	[无]	C++
252	Meeting Rooms	solution	C++
253	Meeting Rooms II	solution	C++
254	Factor Combinations	[无]	C++
257	Binary Tree Paths	solution	C++	Java
259	3Sum Smaller	solution	C++
268	Missing Number	solution	C++
279	Perfect Squares	[无] 四平方和数学解	C++	Java
282	Expression Add Operators	solution	C++
283	Move Zeroes	solution	C++	Java
286	Walls and Gates	solution	C++
287	Find the Duplicate Number		C++
288	Unique Word Abbreviation	solution	C++
290	Word Pattern	[无]	C++
297	Serialize and Deserialize Binary Tree	solution	C++
300	Longest Increasing Subsequence	solution	C++	Java
301	0301-Remove-Invalid-Parentheses	solution [缺：DP+构建]	C++
303	Range Sum Query - Immutable		C++
307	Range Sum Query - Mutable	[缺：BIT]	C++
308	Range Sum Query 2D - Mutable		C++
309	Best Time to Buy and Sell Stock with Cooldown		C++
315	Count of Smaller Numbers After Self	[无]	C++
319	Bulb Switcher	[无]	C++
322	Coin Change	solution	C++
328	Odd Even Linked List	solution	C++
337	House Robber III	[无]	C++
343	Integer Break	[无]	C++	Java
344	Reverse String	[无]	C++
345	Reverse Vowels of a String	[无]	C++
346	Moving Average from Data Stream	[无]	C++
347	Top K Frequent Elements	solution	C++	Java
349	Intersection of Two Arrays	[无]	C++	Java
350	Intersection of Two Arrays II	[无]	C++	Java
359	Logger Rate Limiter	[无]	C++
360	Sort Transformed Array	[无]	C++
370	Range Addition		C++
373	Find K Pairs with Smallest Sums	[无]	C++
374	Guess Number Higher or Lower	solution	C++
377	Combination Sum IV	[无]	C++
378	Kth Smallest Element in a Sorted Matrix	[无]	C++
380	Insert Delete GetRandom O(1)	[无]	C++
381	Insert Delete GetRandom O(1) - Duplicates allowed	[无]	C++
382	Linked List Random Node	[无]	C++
384	Shuffle an Array	solution	C++
386	Lexicographical Numbers		C++
387	First Unique Character in a String	solution	C++	Java
388	Longest Absolute File Path		C++
389	Find the Difference		C++
390	Elimination Game		C++
391	Perfect Rectangle	[缺：矩形求交]	C++
393	UTF-8 Validation	solution	C++
394	Decode String	[无]	C++
398	Random Pick Index	[无]	C++
412	Fizz Buzz	solution	C++
416	Partition Equal Subset Sum	[无]	C++	Java
417	Pacific Atlantic Water Flow	[无]		Java
423	Reconstruct Original Digits from English	solution	C++
429	N-ary Tree Level Order Traversal	[无]	C++
430	Flatten a Multilevel Doubly Linked List	[无]	solution
434	Number of Segments in a String		C++
435	Non-overlapping Intervals	solution	C++	Java
437	Path Sum III	[无]	C++	Java
438	Find All Anagrams in a String	[无]	C++
443	String Compression		C++
447	Number of Boomerangs	[无]	C++	Java
451	Sort Characters By Frequency	[无]	C++
454	4Sum II	[无]	C++	Java
455	Assign Cookies	[无]	C++	Java
470	Implement Rand10() Using Rand7()	solution	C++
473	Matchsticks to Square	solution	C++
474	Ones and Zeroes	solution	C++
478	Generate Random Point in a Circle	solution	C++
485	Max Consecutive Ones	[无]	C++
490	The Maze	solution	C++
494	Target Sum	solution	C++
497	Random Point in Non-overlapping Rectangles	solution	C++
498	Diagonal Traverse	[无]	C++
509	Fibonacci Number	[无]	C++
518	Coin Change 2	[无]	C++
519	Random Flip Matrix	solution	C++
528	Random Pick with Weight	solution	C++
530	Minimum Absolute Difference in BST	[无]		Java
541	Reverse String II	solution	C++
542	01 Matrix	solution	C++
557	Reverse Words in a String III	solution	C++
559	Maximum Depth of N-ary Tree	solution	C++
561	Array Partition I	solution	C++
572	Subtree of Another Tree	solution	C++
583	Delete Operation for Two Strings	solution	C++
589	N-ary Tree Preorder Traversal	solution	C++
590	N-ary Tree Postorder Transversal	solution	C++
598	Range Addition II		C++
599	Minimum Index Sum of Two Lists	solution	C++
600	Non-negative Integers without Consecutive Ones	solution [缺：Bit Manipulation]	C++
622	Design Circular Queue	[无]	C++
637	Average of Levels in Binary Tree	solution	C++
648	Replace Words	[无]	C++
652	Find Duplicate Subtrees	solution	C++
672	Bulb Switcher II	solution	C++
673	Number of Longest Increasing Subsequence	[缺：BIT；线段树]	C++
674	Longest Continuous Increasing Subsequence		C++
675	Cut Off Trees for Golf Event	[缺：A*；Hadlock's Algo]	C++
676	Implement Magic Dictionary	solution	C++
677	Map Sum Pairs	solution	C++
684	Redundant Connection	solution	C++
685	Redundant Connection II	solution	C++
690	Employee Importance	solution	C++
692	Top K Frequent Words	solution	C++
694	Number of Distinct Islands	[review: hash的方式]	C++
695	Max-Area-of-Island		C++
696	Count Binary Substrings		C++
697	Degree of an Array		C++
698	Partition to K Equal Sum Subsets		C++	Java
699	Falling Squares	[缺：线段树；块状链表]	C++
704	Binary Search	[无]	C++
705	Design HashSet	[无]	C++
706	Design HashMap	[无]	C++
707	Design Linked List	[无]	C++
708	Insert into a Cyclic Sorted List	[无]	C++
710	Random Pick with Blacklist	solution	C++
711	Number of Distinct Islands II	[review: hash的方式]	C++
712	Minimum ASCII Delete Sum for Two Strings		C++
713	Subarray Product Less Than K		C++
714	Best Time to Buy and Sell Stock with Transaction Fee		C++
715	Range Module	[缺：set查找]	C++
716	Max Stack	solution	C++
717	1-bit and 2-bit Characters		C++
718	Maximum Length of Repeated Subarray	[缺：Rolling Hash]	C++
719	Find K-th Smallest Pair Distance	[缺：二分搜索]	C++
720	Longest Word in Dictionary	solution	C++
721	Accounts Merge	solution	C++
722	Remove Comments	solution	C++
723	Candy Crush	solution	C++
724	Find Pivot Index	solution	C++
725	Split Linked List in Parts	solution	C++
727	Minimum Window Subsequence	solution	C++
728	Self Dividing Numbers	solution	C++
729	My Calendar I	solution	C++
731	My Calendar II	solution	C++
732	My Calendar III	solution	C++
733	Flood Fill	solution	C++
734	Sentence Similarity	solution	C++
735	Asteroid Collision	solution	C++
736	Parse Lisp Expression	solution	C++
737	Sentence Similarity II	solution	C++
739	Daily Temperatures	solution	C++
740	Delete and Earn	solution	C++
741	Cherry Pickup	solution [缺：自底向上的动态规划]	C++
746	Min Cost Climbing Stairs	solution	C++
747	Largest Number At Least Twice of Others	solution	C++
752	Open the Lock	solution	C++
765	Couples Holding Hands	solution	C++
766	Toeplitz Matrix	solution	C++
771	Jewels and Stones	solution	C++
772	Basic Calculator III	[无]	C++
780	Reaching Points	solution	C++
781	Rabbits in Forest	solution	C++
783	Minimum Distance Between BST Nodes	solution	C++
784	Letter Case Permutation	solution	C++
785	Is Graph Bipartite?	solution	C++
786	K-th Smallest Prime Fraction	solution [缺：分治算法]	C++
787	Cheapest Flights Within K Stops	solution [缺：使用Heap]	C++
788	Rotated Digits	solution	C++
789	Escape The Ghosts	solution	C++
790	Domino and Tromino Tiling	solution [缺：转移矩阵求幂解法]	C++
791	Custom Sort String	solution	C++
792	Number of Matching Subsequences	solution	C++
793	Preimage Size of Factorial Zeroes Function	solution	C++
794	Valid Tic-Tac-Toe State	solution	C++
795	Number of Subarrays with Bounded Maximum	solution	C++
796	Rotate String	solution [缺：Rolling Hash]	C++
797	All Paths From Source to Target	solution	C++
799	Champagne Tower	solution	C++
800	Similar RGB Color	solution	C++
804	Unique Morse Code Words	solution	C++
805	Split Array With Same Average	solution	C++
806	Number of Lines To Write String	solution	C++
807	Max Increase to Keep City Skyline	solution	C++
809	Expressive Words	solution	C++
811	Subdomain Visit Count	solution	C++
817	Linked List Components	solution	C++
819	Most Common Word	solution	C++
841	Keys and Rooms	solution	C++
852	Peak Index in a Mountain Array	solution	C++
853	Car Fleet	solution	C++
854	K-Similar Strings	solution	C++
855	Exam Room	solution	C++
856	Score of Parentheses	solution	C++
857	Minimum Cost to Hire K Workers	solution [缺：二分搜索]	C++
858	Mirror Reflection	solution	C++
859	Buddy Strings	solution	C++
860	Lemonade Change	solution	C++
861	Score After Flipping Matrix	solution	C++
863	All Nodes Distance K in Binary Tree	solution	C++
864	Shortest Path to Get All Keys	solution [缺：Dijkstra]	C++
865	Smallest Subtree with all the Deepest Nodes	solution	C++
866	Prime Palindrome	solution	C++
867	Transpose Matrix	solution	C++
868	Binary Gap	solution	C++
869	Reordered Power of 2	solution	C++
870	Advantage Shuffle	solution	C++
871	Minimum Number of Refueling Stops	solution	C++
872	Leaf-Similar Trees	solution	C++
873	Length of Longest Fibonacci Subsequence	solution	C++
874	Walking-Robot-Simulation	solution	C++
875	Koko Eating Bananas	solution	C++
876	Middle of the Linked List	solution	C++
877	Stone Game	solution	C++
878	Nth Magical Number	solution	C++
879	Profitable Schemes	solution	C++
880	Decoded String at Index	solution	C++
881	Boats to Save People	solution	C++
882	Reachable Nodes In Subdivided Graph	solution	C++
883	Projection Area of 3D Shapes	solution	C++
884	Uncommon Words from Two Sentences	solution	C++
885	Spiral Matrix III	solution	C++
886	Possible Bipartition	solution	C++
888	Fair Candy Swap	solution	C++
889	Construct Binary Tree from Preorder and Postorder Traversal	solution	C++
890	Find and Replace Pattern	solution	C++
891	Sum of Subsequence Widths	solution	C++
892	Surface Area of 3D Shapes	solution	C++
893	Groups of Special-Equivalent Strings	solution	C++
894	All Possible Full Binary Trees	solution	C++
895	Maximum Frequency Stack	solution	C++
896	Monotonic Array	solution	C++
897	Increasing Order Search Tree	solution	C++
898	Bitwise ORs of Subarrays	solution	C++
899	Orderly Queue	solution	C++
900	RLE Iterator	solution	C++
901	Online Stock Span	solution	C++
902	Numbers At Most N Given Digit Set	solution	C++
903	Valid Permutations for DI Sequence	solution [缺：O(n^2) DP]	C++
904	Fruit Into Baskets	solution	C++
905	Sort Array By Parity	solution	C++
906	Super Palindromes	solution	C++
907	Sum of Subarray Minimums	solution	C++
908	Smallest Range I	solution	C++
909	Snakes and Ladders	solution	C++
910	Smallest Range II	solution	C++
911	Online Election	solution	C++
913	Cat and Mouse Game	solution [缺：DFS拓扑排序；DP]	C++
914	X of a Kind in a Deck of Cards	solution	C++
915	Partition Array into Disjoint Intervals	solution	C++
916	Word Subsets	solution	C++
917	Reverse Only Letters	solution	C++
918	Maximum Sum Circular Subarray	solution	C++
919	Complete Binary Tree Inserter	solution	C++
920	Number of Music Playlists	solution [缺：生成函数]	C++
921	Minimum Add to Make Parentheses Valid	solution	C++
922	Sort Array By Parity II	solution	C++
923	3Sum With Multiplicity	solution	C++
924	Minimize Malware Spread	solution	C++
925	Long Pressed Name	solution	C++
926	Flip String to Monotone Increasing	solution	C++
927	Three Equal Parts	solution	C++
928	Minimize Malware Spread II	solution	C++
929	Unique Email Addresses	solution	C++
930	Binary Subarrays With Sum	solution	C++
931	Minimum Path Falling Sum	solution	C++
932	Beautiful Array	solution	C++
933	Number of Recent Calls	solution	C++
934	Shortest Bridge	solution	C++
935	Knight Dialer	solution	C++
936	Stamping The Sequence	solution	C++
937	Reorder Log Files	solution	C++
938	Range Sum of BST	solution	C++
939	Minimum Area Rectangle	solution	C++
940	Distinct Subsequences II	solution	C++
941	Valid Mountain Array	solution	C++
942	DI String Match	solution	C++
943	Find the Shortest Superstring	solution [缺：动态规划]	C++
944	Delete Columns to Make Sorted	solution	C++
945	Minimum Increment to Make Array Unique	solution	C++
946	Validate Stack Sequences	solution	C++
947	Most Stones Removed with Same Row or Column	solution	C++
948	Bag of Tokens	solution	C++
949	Largest Time for Given Digits	solution	C++
950	Reveal Cards In Increasing Order	solution	C++
951	Flip Equivalent Binary Trees	solution	C++
952	Largest Component Size by Common Factor	solution	C++
953	isAlienSorted	solution	C++
954	Array of Doubled Pairs	solution	C++
955	Delete Columns to Make Sorted II	solution	C++
957	Prison Cells After N Days	solution	C++
958	Check Completeness of a Binary Tree	solution	C++
959	Regions Cut By Slashes	solution	C++
960	Delete Columns to Make Sorted III	solution	C++
969	Pancake Sorting	solution	C++
970	Powerful Integers	solution	C++
971	Flip Binary Tree To Match Preorder Traversal	solution	C++
972	Equal Rational Numbers	solution	C++
973	K Closest Points to Origin	solution	C++
974	Subarray Sums Divisible by K	solution	C++
976	Largest Perimeter Triangle	solution	C++
977	Squares of a Sorted Array	solution	C++
978	Longest Turbulent Subarray	solution	C++
979	Distribute Coins in Binary Tree	solution	C++
980	Unique Paths III	solution	C++	Java
981	Time Based Key-Value Store	solution	C++
982	Triples with Bitwise AND Equal To Zero	[无]	C++
983	Minimum Cost For Tickets	solution	C++
984	String Without AAA or BBB	solution	C++
985	Sum of Even Numbers After Queries	solution	C++
986	Interval List Intersections	solution	C++
987	Vertical Order Traversal of a Binary Tree	solution	C++
988	Smallest String Starting From Leaf	solution	C++
989	Add to Array-Form of Integer	solution	C++
990	Satisfiability of Equality Equations	solution	C++
991	Broken Calculator	solution	C++
992	Subarrays with K Different Integers	solution	C++