The code in this repository is my attempts at solving several algo-datastructure problems as found on Leetcode. The solutions here are not always the best or optimal. That being said, feel free to fork the repo and use them for any purposes. Good luck !

Number of Problems solved : 292

Solutions in the following languages :     

#	Title	Solution
1	Two Sum	Java
2	Add Two Numbers	Java
3	Longest Substring Without Repeating Characters	Java
4	Median of Two Sorted Arrays Add to List	Java
5	Longest Palindromic Substring	Java
6	ZigZag Conversion	Java
7	Reverse Integer	Java
8	String to Integer (atoi)	Java
9	Palindrome Number	Java
11	Container With Most Water	Java
12	Integer to Roman	Java
14	Longest Common Prefix	Java
15	3Sum	Java,Javascript
16	3Sum Closest	Java
18	4Sum	Java
21	Merge Two Sorted Lists	Golang,Java,Javascript
25	Reverse Nodes in k-Group	Java
26	Remove Duplicates from Sorted Array	Java
28	Implement strStr()	Java
31	Next Permutation	Java
32	Longest Valid Parentheses	Java
33	Search in Rotated Sorted Array	Java
34	Search for a Range	Java
35	Search Insert Position	Java
37	Sudoku Solver	Java
38	Count and Say	Java
39	Combination Sum	Java
40	Combination Sum II	Java
45	Jump Game II	Java
48	Rotate Image	Java
53	Maximum Subarray	Golang,Java
54	Spiral Matrix	Java
55	Jump Game	Java
56	Merge Intervals	Java
58	Length of Last Word	Java
59	Spiral Matrix II	Java
60	Permutation Sequence	Java
64	Minimum Path Sum	Golang,Java
65	Valid Number	Golang,Java
69	Sqrt(x)	Java
70	Climbing Stairs	Golang,Java
71	Simplify Path	Java
72	Edit Distance	Java
73	Set Matrix Zeroes	Java
75	Sort Colors	Java
79	Word Search	Java
80	Remove Duplicates from Sorted Array II	Java
83	Remove Duplicates from Sorted List	Golang,Java
87	Scramble String	Java
90	Subsets II	Java
91	Decode Ways	Java
92	Reverse Linked List II	Java
93	Restore IP Addresses	Java
94	Binary Tree Inorder Traversal	Java
97	Interleaving String	Java
98	Validate Binary Search Tree	Golang,Java
100	Same Tree	Golang,Java
101	Symmetric Tree	Java
102	Binary Tree Level Order Traversal	Golang,Java
103	Binary Tree Zigzag Level Order Traversal	Java
104	Maximum Depth of Binary Tree	Java
105	Construct Binary Tree from Preorder and Inorder Traversal	Golang,Java
106	Construct Binary Tree from Inorder and Postorder Traversal	Golang,Java
107	Binary Tree Level Order Traversal II	Java
108	Convert Sorted Array to Binary Search Tree	Golang,Java
110	Balanced Binary Tree	Golang,Java
111	Minimum Depth of Binary Tree	Golang,Java
112	Path Sum	Golang,Java
113	Path Sum II	Golang,Java
114	Flatten Binary Tree to Linked List	Golang,Java
116	Populating Next Right Pointers in Each Node	Java
117	Refer to Problem 116	Java
118	Refer to Problem 116	Java
120	Triangle	Golang,Java
121	Best Time to Buy and Sell Stock	Java
122	Best Time to Buy and Sell Stock II	Java
124	Binary Tree Maximum Path Sum	Java
129	Sum Root to Leaf Numbers	Java
130	Surrounded Regions	Java
131	Palindrome Partitioning	Java
136	Single Number	Java
139	Word Break	Java
141	Linked List Cycle	Java
144	Binary Tree Preorder Traversal	Golang,Java
146	LRU Cache	Java
148	Sort List	Java
150	Evaluate Reverse Polish Notation	Java
155	Min Stack	Java
160	Intersection of Two Linked Lists	Java
162	Find Peak Element	Java
165	Compare Version Numbers	Java
166	Fraction to Recurring Decimal	Java
168	Excel Sheet Column Title	Java
169	Majority Element	Java
172	Factorial Trailing Zeroes	Java
192	Word Frequency	Bash
193	Valid Phone Numbers	Bash
195	Tenth Line	Bash
198	House Robber	Golang,Java
199	Binary Tree Right Side View	Golang,Java
200	Number of Islands	Java
201	Bitwise AND of Numbers Range	Java
202	Happy Number	Java
203	Remove Linked List Elements	Golang,Java
206	Reverse Linked List	Golang,Java
208	Implement Trie (Prefix Tree)	Java
212	Word Search II	Java
216	Combination Sum III	Java
226	Longest Substring Without Repeating Characters	Golang,Java
230	Kth Smallest Element in a BST	Golang,Java
234	Palindrome Linked List	Golang,Java
235	Lowest Common Ancestor of a Binary Search Tree	Java
236	Lowest Common Ancestor of a Binary Tree	Java
237	Delete Node in a Linked List	Java
238	Product of Array Except Self	Java
240	Search a 2D Matrix II	Java
241	Different Ways to Add Parentheses	Java
257	Binary Tree Paths	Java
279	Perfect Squares	Java
281	Zigzag Iterator	Java
289	Game of Life	Java
297	Serialize and Deserialize Binary Tree	Java
299	Bulls and Cows	Java
300	Longest Increasing Subsequence	Java
322	Coin Change	Java
326	Power of Three	Java
331	Verify Preorder Serialization of a Binary Tree	Java
334	Increasing Triplet Subsequence	Java
341	Flatten Nested List Iterator	Java
343	Integer Break	Java
355	Design Twitter	Java
357	Count Numbers with Unique Digits	Java
365	Water and Jug Problem	Java
367	Valid Perfect Square	Java
376	Wiggle Subsequence	Java
377	Combination Sum IV	Java
380	Insert Delete GetRandom O(1)	Java
381	Insert Delete GetRandom O(1) - Duplicates allowed	Java
383	Ransom Note	Java
384	Shuffle an Array	Java
388	Longest Absolute File Path	Java
392	Is Subsequence	Golang,Java
394	Decode String	Java
395	Longest Substring with At Least K Repeating Characters	Java
396	Rotate Function	Java
404	Sum of Left Leaves	Golang,Java
413	Arithmetic Slices	Golang,Java
416	Partition Equal Subset Sum	Java
424	Longest Repeating Character Replacement	Java
432	All O`one Data Structure	Java
437	Path Sum III	Golang,Java
449	Serialize and Deserialize BST	Java
450	Delete Node in a BST	Golang,Java
451	Sort Characters By Frequency	Java
454	4Sum II	Java
456	Pattern	Java
460	LFU Cache	Java
468	Validate IP Address	Java
472	Concatenated Words	Java
486	Predict the Winner	Golang,Java
495	Teemo Attacking	Java
501	Find Mode in Binary Search Tree	Java
504	Base 7	Java
507	Perfect Number	Java
508	Most Frequent Subtree Sum	Golang,Java
513	Find Bottom Left Tree Value	Golang,Java
515	Find Largest Value in Each Tree Row	Java
516	Longest Palindromic Subsequence	Java
520	Detect Capital	Java
521	Longest Uncommon Subsequence I	Java
522	Longest Uncommon Subsequence II	Java
524	Longest Word in Dictionary through Deleting	Java
526	Beautiful Arrangement	Java
538	Convert BST to Greater Tree	Java
540	Single Element in a Sorted Array	Java
541	Reverse String II	Java
542	01 Matrix	Golang,Java
543	Diameter of Binary Tree	Golang,Java
547	Friend Circles	Java
551	Student Attendance Record I	Java
552	Student Attendance Record II	Java
554	Brick Wall	Java
556	Next Greater Element III	Java
557	Reverse Words in a String III	Java
560	Subarray Sum Equals K	Java
561	Array Partition I	Java
562	Longest Line of Consecutive One in Matrix	Java
563	Binary Tree Tilt	Java
565	Array Nesting	Java
566	Reshape the Matrix	Java
567	Permutation in String	Java
572	Subtree of Another Tree	Golang,Java
575	Distribute Candies	Java
581	Shortest Unsorted Continuous Subarray	Golang,Java
582	ZigZag Conversion	Golang,Java
583	Delete Operation for Two Strings	Java
588	Design In-Memory File System	Java
591	Tag Validator	Java
592	Fraction Addition and Subtraction	Java
593	Valid Square	Java
594	Longest Harmonious Subsequence	Java
598	Range Addition II	Java
599	Minimum Index Sum of Two Lists	Java
605	Can Place Flowers	Java
606	Construct String from Binary Tree	Java
609	Find Duplicate File in System	Java
611	Valid Triangle Number	Java
616	Add Bold Tag in String	Java
617	Merge Two Binary Trees	Java
621	Task Scheduler	Java
623	Add One Row to Tree	Java
624	Maximum Distance in Arrays	Java
625	Minimum Factorization	Java
628	Maximum Product of Three Numbers	Java
630	Course Schedule III	Java
631	Design Excel Sum Formula	Java
633	Sum of Square Numbers	Java
635	Design Log Storage System	Java
637	Average of Levels in Binary Tree	Java
649	Dota2 Senate My SubmissionsBack to Contest	Java
650	2 Keys Keyboard My SubmissionsBack to Contest	Java
651	4 Keys Keyboard My SubmissionsBack to Contest	Java
653	Two Sum IV - Input is a BST	Java
657	Judge Route Circle	Java
669	Trim a Binary Search Tree	Java
671	Second Minimum Node In a Binary Tree	Java
690	Employee Importance	Java
692	Top K Frequent Words	Java
695	Max Area of Island	Java
697	Degree of an Array	Java
717	1-bit and 2-bit Characters	Java
720	Longest Word in Dictionary	Java
724	Find Pivot Index	Java
725	Split Linked List in Parts	Java
728	Self Dividing Numbers	Java
733	Flood Fill	Java
739	Daily Temperatures	Java
740	Delete and Earn	Java
744	Find Smallest Letter Greater Than Target	Java
746	Min Cost Climbing Stairs	Java
747	Largest Number Greater Than Twice of Others	Java
749	Shortest Completing Word	Java
760	Find Anagram Mappings	Java
766	Toeplitz Matrix	Java
783	Minimum Distance Between BST Nodes	Java
784	Letter Case Permutation	Java
788	Rotated Digits	Java
796	Rotate String	Java
804	Unique Morse Code Words	Java
811	Subdomain Visit Count	Java
875	Koko Eating Bananas	Java
938	Range Sum of BST	Java
997	Find the Town Judge	Java
999	Available Captures for Rook	Java
1020	Number of Enclaves	Java
1231	Divide Chocolate	Java
1265	Print Immutable Linked List in Reverse	Java
1269	Number of Ways to Stay in the Same Place After Some Steps	Java
1272	Remove Interval	Java
1273	Delete Tree Nodes	Java
1302	Deepest Leaves Sum	Java
1306	Sum of Nodes with Even-Valued Grandparent	Java
1315	Sum of Nodes with Even-Valued Grandparent	Java
1324	Print Words Vertically	Java
1325	Delete Leaves With a Given Value	Java
1338	Reduce Array Size to The Half	Java
1339	Maximum Product of Splitted Binary Tree	Java
1357	Apply Discount Every n Orders	Java
1358	Number of Substrings Containing All Three Characters	Java
1371	Find the Longest Substring Containing Vowels in Even Counts	Java
1385	Find the Distance Value Between Two Arrays	Java
1394	Find Lucky Integer in an Array	Java
1395	Count Number of Teams	Java
1413	Minimum Value to Get Positive Step by Step Sum	Java
1423	Maximum Points You Can Obtain from Cards	Java
1429	First Unique Number	Java
1441	Build an Array With Stack Operations	Java
1443	Minimum Time to Collect All Apples in a Tree	Java
1448	Count Good Nodes in Binary Tree	Java
1451	Rearrange Words in a Sentence	Java
1456	Maximum Number of Vowels in a Substring of Given Length	Java
1457	Pseudo-Palindromic Paths in a Binary Tree	Java
1471	The k Strongest Values in an Array	Java
1472	Design Browser History	Java
1480	Running Sum of 1d Array	Java
1481	Least Number of Unique Integers after K Removals	Java
1482	Minimum Number of Days to Make m Bouquets	Java
1483	Kth Ancestor of a Tree Node	Java
1485	Clone Binary Tree With Random Pointer	Java
1486	XOR Operation in an Array	Java
1487	Making File Names Unique	Java
1488	Avoid Flood in The City	Java