My solutions of different Leetcode problems, challenges, interviews, and contests.

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• 30 Days Leetcoding Challenge

Versions of used programming languages:

• Kotlin 1.3.71;
• Java 14.

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30 Days Leetcoding Challenge

Day	Challenge	Solution
April 1	Single Number	Solution.kt
April 2	Happy Number	Solution.kt
April 3	Maximum Subarray	Solution.kt
April 4	Move Zeroes	Solution.kt
April 5	Best Time to Buy and Sell Stock II	Solution.kt
April 6	Group Anagrams	Solution.kt
April 7	Counting Elements	Solution.kt
April 8	Middle of the Linked List	Solution.kt
April 9	Backspace String Compare	Solution.kt
April 10	Min Stack	Solution.kt
April 11	Diameter of Binary Tree	Solution.kt
April 12	Last Stone Weight	Solution.kt
April 13	Contiguous Array	Solution.kt
April 14	Perform String Shifts	Solution.kt
April 15	Product of Array Except Self	Solution.kt
April 16	Valid Parenthesis String	Solution.kt
April 17	Number of Islands	Solution.kt
April 18	Minimum Path Sum	Solution.kt
April 19	Search in Rotated Sorted Array	Solution.kt
April 20	Construct Binary Search Tree from Preorder Traversal	Solution.kt
April 21	Leftmost Column with at Least a One	Solution.kt
April 22	Subarray Sum Equals K	Solution.kt
April 23	Bitwise AND of Numbers Range	Solution.kt
April 24	LRU Cache	LRUCache.kt
April 25	Jump Game	Solution.kt
April 26	Longest Common Subsequence	Solution.kt
April 27	Maximal Square	Solution.kt
April 28	First Unique Number	FirstUnique.kt
April 29	Binary Tree Maximum Path Sum	Solution.kt
April 30	Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree	Solution.kt

May LeetCoding Challenge

Day	Challenge	Solution
May 1	First Bad Version	Solution.kt
May 2	Jewels and Stones	Solution.kt
May 3	Ransom Note	Solution.kt
May 4	Number Complement	Solution.kt
May 5	First Unique Character in a String	Solution.kt
May 6	Majority Element	Solution.kt
May 7	Cousins in Binary Tree
May 8	Check If It Is a Straight Line	Solution.kt
May 9	Valid Perfect Square	Solution.kt
May 10	Find the Town Judge
May 11	Flood Fill	Solution.kt
May 12	Single Element in a Sorted Array	Solution.kt
May 13	Remove K Digits	Solution.kt
May 14
May 15
May 16
May 17
May 18
May 19
May 20
May 21
May 22
May 23
May 24
May 25
May 26
May 27
May 28
May 29
May 30
May 31