Leetcode problems & solutions

Java solution for some of the leetcode problems.
Will keep on updating as I solve more.

Hard problems

Leetcode Problem no.	My Solution
622	Design Circular Queue
969	Pancake Sorting
957	Prison Cells After N Days
966	Vowel Spellchecker
6	ZigZag Conversion
2	Add two numbers
139	Word Break
11	Container With Most Water
15	3Sum
1023	Binary String With Substrings Representing 1 To N
1021	Best Sightseeing Pair
641	Design Circular Deque
1019	Next Greater Node In Linked List
1017	Convert to Base -2
1020	Number of Enclaves
684	Redundant Connection II
1024	Video Stitching
1023	Camelcase Matching

Leetcode Problem no.	My Solution
953	Verifying An Alien Dictionary
961	N-Repeated Element in Size 2N Array
970	Powerful Integers
1	Two Sum
13	Roman to Integer
122	Best time to buy and sell stock II
121	Best time to buy and sell stock
53	Maximum Subarray
1018	Binary Prefix Divisible By 5
225	Implement Stack using Queues
232	Implement Queue using Stacks
707	Design Linked List
1022	Sum of Root To Leaf Binary Numbers
1021	Remove Outermost Parentheses

The problem no. could be different than actual problem no. on leetcode site.
In spite of most leetcode problems not asking for a main method, you might still see one in some solutions here. I added it to test initial cases, while solving it locally.
All the solutions uploaded here have passed every test case and has been accepted at the time of my submission.
You can also check out the problems listed here on leetcode site, I've hyperlinked the problem numbers.
I do not own, nor did I design any of the problems listed here. But the solutions are all my doing.