LeetCode

Solutions for the LeetCode problems.

Problems

#	Title	Difficulty	Solution
1	Two Sum	💚	C++
2	Add Two Numbers	💛	C
3	Longest Substring Without Repeating Characters	💛	C#
6	ZigZag Conversion	💛	C++
7	Reverse Integer	💚	C++
8	String to Integer (atoi)	💛	C
9	Palindrome Number	💚	C
13	Roman to Integer	💚	C++
14	Longest Common Prefix	💚	C++
20	Valid Parentheses	💚	C++
21	Merge Two Sorted Lists	💚	C++
24	Swap Nodes in Pairs	💛	C++
26	Remove Duplicates from Sorted Array	💚	C
27	Remove Element	💚	C
33	Search in Rotated Sorted Array	💛	C++
34	Search for a Range	💛	C++
35	Search Insert Position	💚	C / C#
50	Pow(x, n)	💚	C
58	Length of Last Word	💚	C#
62	Unique Paths	💛	Java
63	Unique Paths II	💛	Java
66	Plus One	💚	C++
69	Sqrt(x)	💚	C++
71	Simplify Path	💛	Java
75	Sort Colors	💛	C
83	Remove Duplicates from Sorted List	💚	C
88	Merge Sorted Array	💚	C++
94	Binary Tree Inorder Traversal	💛	C++
98	Validate Binary Search Tree	💛	C++
100	Same Tree	💚	C
101	Symmetric Tree	💚	C++
102	Binary Tree Level Order Traversal	💛	C++
103	Binary Tree Zigzag Level Order Traversal	💛	C++
104	Maximum Depth of Binary Tree	💚	C / Java
105	Construct Binary Tree from Preorder and Inorder Traversal	💛	C++
106	Construct Binary Tree from Inorder and Postorder Traversal	💛	C++
107	Binary Tree Level Order Traversal II	💚	C++
111	Minimum Depth of Binary Tree	💚	C++
112	Path Sum	💚	C++
116	Populating Next Right Pointers in Each Node	💛	C++
117	Populating Next Right Pointers in Each Node II	💛	C
118	Pascal's Triangle	💚	C++
119	Pascal's Triangle II	💚	C++
125	Valid Palindrome	💚	C++
136	Single Number	💚	C
141	Linked List Cycle	💚	C
144	Binary Tree Preorder Traversal	💚	C++ / Java
145	Binary Tree Postorder Traversal	💚	C++ / Java
150	Evaluate Reverse Polish Notation	💛	C++
153	Find Minimum in Rotated Sorted Array	💛	C++
154	Find Minimum in Rotated Sorted Array II	❤️	C++
155	Min Stack	💚	C++
160	Intersection of Two Linked Lists	💚	C++
162	Find Peak Element	💛	C++
168	Excel Sheet Column Title	💚	C++
169	Majority Element	💚	C++
171	Excel Sheet Column Number	💚	C++
173	Binary Search Tree Iterator	💛	C++
181	Employees Earning More Than Their Managers	💚	MySQL
182	Duplicate Emails	💚	MySQL
183	Customers Who Never Order	💚	MySQL
190	Reverse Bits	💚	C
191	Number of 1 Bits	💚	C++
200	Number of Islands	💛	C++
201	Bitwise AND of Numbers Range	💛	C++
205	Isomorphic Strings	💚	C++
206	Reverse Linked List	💚	C
208	Implement Trie (Prefix Tree)	💛	C++
217	Contains Duplicate	💚	C++
225	Implement Stack using Queues	💚	C++
226	Invert Binary Tree	💚	C / C++
231	Power of Two	💚	C++
232	Implement Queue using Stacks	💚	C++
236	Lowest Common Ancestor of a Binary Tree	💛	C
237	Delete Node in a Linked List	💚	C++
238	Product of Array Except Self	💛	C++
242	Valid Anagram	💚	C++
257	Binary Tree Paths	💚	C++
258	Add Digits	💚	C
268	Missing Number	💚	C
278	First Bad Version	💚	C++
283	Move Zeroes	💚	C
289	Game of Life	💛	C / C++
292	Nim Game	💚	C
297	Serialize and Deserialize Binary Tree	❤️	C++
303	Range Sum Query - Immutable	💚	Java
326	Power of Three	💚	C
338	Counting Bits	💛	C
344	Reverse String	💚	C++
345	Reverse Vowels of a String	💚	C++
349	Intersection of Two Arrays	💚	C++
350	Intersection of Two Arrays II	💚	C++
367	Valid Perfect Square	💚	C++
374	Guess Number Higher or Lower	💚	C++
383	Ransom Note	💚	C++
384	Shuffle an Array	💛	C++
387	First Unique Character in a String	💚	C
389	Find the Difference	💚	C / C#
404	Sum of Left Leaves	💚	C
405	Convert a Number to Hexadecimal	💚	C++
409	Longest Palindrome	💚	C
412	Fizz Buzz	💚	C++ / C#
414	Third Maximum Number	💚	C++
429	N-ary Tree Level Order Traversal	💚	C++
430	Flatten a Multilevel Doubly Linked List	💛	Java
434	Number of Segments in a String	💚	C++
441	Arranging Coins	💚	C++
442	Find All Duplicates in an Array	💛	C++
450	Delete Node in a BST	💛	C++
461	Hamming Distance	💚	C++
463	Island Perimeter	💚	C++
476	Number Complement	💚	C
478	Generate Random Point in a Circle	💛	C++ / JavaScript
482	License Key Formatting	💚	C++
485	Max Consecutive Ones	💚	C++
495	Teemo Attacking	💛	C / C++
496	Next Greater Element I	💚	C++
500	Keyboard Row	💚	C++
504	Base 7	💚	C++
506	Relative Ranks	💚	C++
509	Fibonacci Number	💚	C
513	Find Bottom Left Tree Value	💛	C++
515	Find Largest Value in Each Tree Row	💛	C++
520	Detect Capital	💚	C
529	Minesweeper	💛	C++
535	Encode and Decode TinyURL	💛	C++
538	Convert BST to Greater Tree	💚	C++
557	Reverse Words in a String III	💚	C++
559	Maximum Depth of N-ary Tree	💚	C++
566	Reshape the Matrix	💚	C++
575	Distribute Candies	💚	C++
589	N-ary Tree Preorder Traversal	💚	C++
590	N-ary Tree Postorder Traversal	💚	C++
594	Longest Harmonious Subsequence	💚	Java
595	Big Countries	💚	MySQL
596	Classes More Than 5 Students	💚	MySQL
598	Range Addition II	💚	C++
599	Minimum Index Sum of Two Lists	💚	C++
606	Construct String from Binary Tree	💚	C++
617	Merge Two Binary Trees	💚	C++
620	Not Boring Movies	💚	MySQL
622	Design Circular Queue	💛	C
627	Swap Salary	💚	MySQL
628	Maximum Product of Three Numbers	💚	C++
637	Average of Levels in Binary Tree	💚	C++
643	Maximum Average Subarray I	💚	C++
653	Two Sum IV - Input is a BST	💚	C++
654	Maximum Binary Tree	💛	C++
657	Judge Route Circle	💚	C#
658	Find K Closest Elements	💛	C++
661	Image Smoother	💚	C++
669	Trim a Binary Search Tree	💚	C
670	Maximum Swap	💛	C++
682	Baseball Game	💚	C++
690	Employee Importance	💚	C++
693	Binary Number with Alternating Bits	💚	C#
695	Max Area of Island	💛	C++
700	Search in a Binary Search Tree	💚	C++
701	Insert into a Binary Search Tree	💛	C++
704	Binary Search	💚	C++
705	Design HashSet	💚	C++
706	Design HashMap	💚	C++
709	To Lower Case	💚	C
717	1-bit and 2-bit Characters	💚	C#
722	Remove Comments	💛	C++
724	Find Pivot Index	💚	C++
728	Self Dividing Numbers	💚	C++
733	Flood Fill	💚	C++
744	Find Smallest Letter Greater Than Target	💚	C
747	Largest Number At Least Twice of Others	💚	C
752	Open the Lock	💛	C++
766	Toeplitz Matrix	💚	C++
771	Jewels and Stones	💚	C++ / Java
784	Letter Case Permutation	💚	C++
788	Rotated Digits	💚	C
791	Custom Sort String	💛	C++
796	Rotate String	💚	C++
804	Unique Morse Code Words	💚	C++
806	Number of Lines To Write String	💚	C / C++
807	Max Increase to Keep City Skyline	💛	C++
811	Subdomain Visit Count	💚	C++
814	Binary Tree Pruning	💛	C++
817	Linked List Components	💛	C++
821	Shortest Distance to a Character	💚	C++
824	Goat Latin	💚	C++
830	Positions of Large Groups	💚	C++
831	Masking Personal Information	💛	C++
832	Flipping an Image	💚	C++
841	Keys and Rooms	💛	C++
852	Peak Index in a Mountain Array	💚	C++
859	Buddy Strings	💚	C++
860	Lemonade Change	💚	C++
867	Transpose Matrix	💚	C++
868	Binary Gap	💚	C++
872	Leaf-Similar Trees	💚	C++
876	Middle of the Linked List	💚	C
884	Uncommon Words from Two Sentences	💚	C++
890	Find and Replace Pattern	💛	C++
896	Monotonic Array	💚	C
897	Increasing Order Search Tree	💚	C++
905	Sort Array By Parity	💚	C++
908	Smallest Range I	💚	C
912	Sort an Array	💛	C++
917	Reverse Only Letters	💚	C++
921	Minimum Add to Make Parentheses Valid	💛	C / C++
922	Sort Array By Parity II	💚	C++
925	Long Pressed Name	💚	C
929	Unique Email Addresses	💚	C++
933	Number of Recent Calls	💚	C++
938	Range Sum of BST	💛	C / Java
941	Valid Mountain Array	💚	C++
944	Delete Columns to Make Sorted	💚	C++
946	Validate Stack Sequences	💛	C++
951	Flip Equivalent Binary Trees	💛	C++
953	Verifying an Alien Dictionary	💚	C++
961	N-Repeated Element in Size 2N Array	💚	C / C++
965	Univalued Binary Tree	💚	C++
976	Largest Perimeter Triangle	💚	C++
977	Squares of a Sorted Array	💚	C++
993	Cousins in Binary Tree	💚	C++
997	Find the Town Judge	💚	C++
999	Available Captures for Rook	💚	C++
1002	Find Common Characters	💚	C++
1008	Construct Binary Search Tree from Preorder Traversal	💛	Java
1021	Remove Outermost Parentheses	💚	C++
1028	Recover a Tree From Preorder Traversal	❤️	C++
1038	Binary Search Tree to Greater Sum Tree	💛	C++
1046	Last Stone Weight	💚	C++
1071	Greatest Common Divisor of Strings	💚	Java
1078	Occurrences After Bigram	💚	Java
1089	Duplicate Zeros	💚	C++
1108	Defanging an IP Address	💚	C / C++
1114	Print in Order	💚	Java
1115	Print FooBar Alternately	💚	Java
1116	Print Zero Even Odd	💛	Java
1117	Building H2O	💛	Java
1154	Day of the Year	💚	C++
1189	Maximum Number of Balloons	💚	C++
1195	Fizz Buzz Multithreaded	💛	Java
1207	Unique Number of Occurrences	💚	C++
1221	Split a String in Balanced Strings	💚	C
1227	Airplane Seat Assignment Probability	💛	C++
1252	Cells with Odd Values in a Matrix	💚	C++ / JavaScript
1260	Shift 2D Grid	💚	C++
1281	Subtract the Product and Sum of Digits of an Integer	💚	C
1282	Group the People Given the Group Size They Belong To	💛	JavaScript
1287	Element Appearing More Than 25% In Sorted Array	💚	C++
1290	Convert Binary Number in a Linked List to Integer	💚	JavaScript
1295	Find Numbers with Even Number of Digits	💚	C
1304	Find N Unique Integers Sum up to Zero	💚	C++
1309	Decrypt String from Alphabet to Integer Mapping	💚	C++
1313	Decompress Run-Length Encoded List	💚	C
1323	Maximum 69 Number	💚	C++ / JavaScript
1331	Rank Transform of an Array	💚	C++
1342	Number of Steps to Reduce a Number to Zero	💚	C++ / JavaScript
1365	How Many Numbers Are Smaller Than the Current Number	💚	C++ / JS
1379	Find a Corresponding Node of a Binary Tree in a Clone of That Tree	💛	C++ / JavaScript
1380	Lucky Numbers in a Matrix	💚	C++
1394	Find Lucky Integer in an Array	💚	C++
1417	Reformat The String	💚	C
1431	Kids With the Greatest Number of Candies	💚	C++
1436	Destination City	💚	C++
1446	Consecutive Characters	💚	C++
1447	Simplified Fractions	💛	C++
1455	Check If a Word Occurs As a Prefix of Any Word in a Sentence	💚	C++
1464	Maximum Product of Two Elements in an Array	💚	C++
1470	Shuffle the Array	💚	C++
1476	Subrectangle Queries	💛	C++
1480	Running Sum of 1d Array	💚	C++
1486	XOR Operation in an Array	💚	C++ / JavaScript
1496	Path Crossing	💚	C++
1512	Number of Good Pairs	💚	C++
1518	Water Bottles	💚	C++
1528	Shuffle String	💚	C / C++ / JavaScript
1539	Kth Missing Positive Number	💚	C++
1556	Thousand Separator	💚	C++
1572	Matrix Diagonal Sum	💚	C++ / JavaScript
1576	Replace All ?'s to Avoid Consecutive Repeating Characters	💚	C++
1588	Sum of All Odd Length Subarrays	💚	C++
1592	Rearrange Spaces Between Words	💚	C++
1598	Crawler Log Folder	💚	C++
1603	Design Parking System	💚	JavaScript
1609	Even Odd Tree	💛	C++
1614	Maximum Nesting Depth of the Parentheses	💚	C++
1624	Largest Substring Between Two Equal Characters	💚	C++
1637	Widest Vertical Area Between Two Points Containing No Points	💛	C++
1646	Get Maximum in Generated Array	💚	C++
1656	Design an Ordered Stream	💚	C++ / Java / JavaScript
1662	Check If Two String Arrays are Equivalent	💚	C++
1672	Richest Customer Wealth	💚	C++
1678	Goal Parser Interpretation	💚	Java
1684	Count the Number of Consistent Strings	💚	C++ / Java / JavaScript
1694	Reformat Phone Number	💚	C++
1704	Determine if String Halves Are Alike	💚	Java
1732	Find the Highest Altitude	💚	C++ / Java / JavaScript
1736	Latest Time by Replacing Hidden Digits	💚	C++ / Java / JavaScript
1743	Restore the Array From Adjacent Pairs	💛	C++
1748	Sum of Unique Elements	💚	C++ / Java / JavaScript
1752	Check if Array Is Sorted and Rotated	💚	C++ / Java / JavaScript
1758	Minimum Changes To Make Alternating Binary String	💚	C++ / Java / JavaScript
1768	Merge Strings Alternately	💚	C++ / Java / JavaScript
1773	Count Items Matching a Rule	💚	C++ / Java / JavaScript
1779	Find Nearest Point That Has the Same X or Y Coordinate	💚	C++ / Java / JavaScript
1784	Check if Binary String Has at Most One Segment of Ones	💚	C++ / Java / JavaScript
2278	Percentage of Letter in String	💚	Java

💚 - Easy problem; 💛 - Medium problem; ❤️ - Hard problem.