leetcode

Leetcode

Index

Sl No.	Topic	Link
1.	Array	Search Here
2.	Binary Search	Search Here
3.	Binary Search Tree	Search Here
4.	Bit Manipulation	Search Here
5.	Contests	Search Here
6.	Databases	Search Here
7.	Geometry	Search Here
8.	Greedy	Search Here
9.	Hash Table	Search Here
10.	Linked-List	Search Here
11.	Math	Search Here
12.	Minimax	Search Here
13.	Mock	Search Here
14.	Stack	Search Here
15.	String	Search Here
16.	Tree	Search Here
17.	April '20 Challenge	Search Here
18.	May '20 Challenge	Search Here
19.	June '20 Challenge	Search Here
20.	July '20 Challenge	Search Here
21.	August '20 Challenge	Search Here

• Array

  Sl No.	Level	Questions	Solution
  1.	Easy	Two Sum	Python | Java
  4.	Hard	Median of Two Sorted Arrays	Python
  7.	Easy	Reverse Integer	Python | Java
  9.	Easy	Palindrome Number	Python | C | C++
  13.	Easy	Roman to Integer	Python
  26.	Easy	Remove Duplicates from Sorted Array	Python
  27.	Easy	Remove Element	Python
  35.	Easy	Search Insert Position	Python | C++
  42.	Hard	Trapping Rain Water	Python
  53.	Easy	Maximum Subarray	Python
  64.	Medium	Minimum Path Sum	Python
  66.	Easy	Plus One	Python
  88.	Easy	Merge Sorted Array	Python
  121.	Easy	Best Time to Buy and Sell Stock	Python
  154.	Hard	Find Minimum in Rotated Sorted Array II	Python
  167.	Easy	Two Sum II - Input array is sorted	Python
  169.	Easy	Majority Element	Python
  189.	Easy	Rotate Array	Python
  238.	Medium	Product of Array Except Self	Python
  283.	Easy	Move Zeroes	Python
  344.	Easy	Revese String	Python
  349.	Easy	Intersection of Two Arrays	Python
  414.	Easy	Third Maximum Number	Python
  442.	Medium	Find All Duplicates in an Array	Python
  448.	Easy	Find All Numbers Disappeared in an Array	Python
  509.	Easy	Fibonacci Number	Python
  532.	Easy	K-diff Pairs in an Array	Python
  566.	Easy	Reshape the Matrix	Python
  628.	Easy	Maximum Product of Three Numbers	Python
  665.	Easy	Non-decreasing Array	Python
  744.	Easy	Find Smallest Letter Greater Than Target	Python | C++
  812.	Easy	Largest Triangle Area	Python
  832.	Easy	Flipping an Image	Python
  905.	Easy	Sort Array By Parity	Python
  922.	Easy	Sort Array By Parity II	Python
  941.	Easy	Valid Mountain Array	Python
  977.	Easy	Squares of a Sorted Array	Python
  985.	Easy	Sum of Even Numbers After Queries	Python
  999.	Easy	Available Captures for Rook	Python
  1002.	Easy	Find Common Characters	Python
  1051.	Easy	Height Checker	Python
  1122.	Easy	Relative Sort Array	Python
  1160.	Easy	Find Words That Can Be Formed by Characters	Python
  1200.	Easy	Minimum Absolute Difference	Python
  1232.	Easy	Check If It Is a Straight Line	Python
  1385.	Easy	Find the Distance Value Between Two Arrays	Python
  1394.	Easy	Find Lucky Integer in an Array	Python
  1395.	Medium	Count Number of Teams	Python
  1399.	Easy	Count Largest Group	Python
  1464.	Easy	Maximum Product of Two Elements in an Array	Python

• Binary Search

  Sl No.	Level	Questions	Solution
  33.	Medium	Search in Rotated Sorted Array	Python
  74.	Medium	Search a 2D Matrix	Python
  240.	Medium	Search a 2D Matrix II	Python
  278.	Easy	278. First Bad Version	Python
  367.	Easy	Valid Perfect Square	Python
  441.	Easy	Arranging Coins	Python
  528.	Medium	Random Pick with Weight	Python
  540.	Medium	Single Element in a Sorted Array	Python
  704.	Easy	Binary Search	Python
  1198.	Medium	Find Smallest Common Element in All Rows	Python
  1428.	Medium	Leftmost Column with at Least a One	Python

• Binary Search Tree

  Sl No.	Level	Questions	Solution
  1038.	Medium	Binary Search Tree to Greater Sum Tree	Python

• Bit Manipulation

  Sl No.	Level	Questions	Solution
  136.	Easy	Single Number	Python
  231.	Easy	Power of Two	Python
  338.	Medium	Counting Bits	Python
  342.	Easy	Power of Four	Python
  461.	Easy	Hamming Distance	Python
  476.	Easy	Number Complement	Python
  1342.	Easy	Number of Steps to Reduce a Number to Zero	Python

• Contests

  Sl No.	Level	Questions	Solution
  1385.	Easy	Find the Distance Value Between Two Arrays	Python

• Databases

  Sl No.	Level	Questions	Solution
  175.	Easy	Combine Two Tables	MySQL
  176.	Easy	Second Highest Salary	MySQL
  181.	Easy	Employees Earning More Than Their Managers	MySQL
  182.	Easy	Duplicate Emails	MySQL
  183.	Easy	Customers Who Never Order	MySQL
  196.	Easy	Delete Duplicate Emails	MySQL
  595.	Easy	Big Countries	MySQL
  596.	Easy	Classes More Than 5 Students	MySQL
  620.	Easy	Not Boring Movies	MySQL
  627.	Easy	Swap Salary	MySQL

• Geometry

  Sl No.	Level	Questions	Solution
  1401.	Medium	Circle and Rectangle Overlapping	Python

• Greedy

  Sl No.	Level	Questions	Solution
  122.	Easy	Best Time to Buy and Sell Stock II	Python
  1029.	Easy	Two City Scheduling	Python
  1046.	Easy	Last Stone Weight	Python
  1196.	Easy	How Many Apples Can You Put into the Basket	Python

• Hash Table

  Sl No.	Level	Questions	Solution
  202.	Easy	Happy Number	Python
  347.	Medium	Top K Frequent Elements	Python
  387.	Easy	First Unique Character in a String	Python
  451.	Medium	Sort Characters By Frequency	Python
  535.	Medium	Encode and Decode TinyURL	Python
  705.	Easy	Design HashSet	Python
  1207.	Easy	Unique Number of Occurrences	Python
  1365.	Easy	How Many Numbers Are Smaller Than the Current Number	Python
  1426.	Easy	Counting Elements	Python

• Linked-List

  Sl No.	Level	Questions	Solution
  2.	Medium	Add Two Numbers	Python
  19.	Medium	Remove Nth Node From End of List	Python
  21.	Easy	Merge Two Sorted Lists	Python
  24.	Medium	Swap Nodes in Pairs	Python
  23.	Hard	Merge k Sorted Lists	Python
  61.	Medium	Rotate List	Python
  83.	Easy	Remove Duplicates from Sorted List	Python | C++
  92.	Medium	Reverse Linked List II	Python
  160.	Easy	Intersection of Two Linked Lists	Python
  203.	Easy	Remove Linked List Elements	Python
  206.	Easy	Reverse Linked List	Python | C
  234.	Easy	Palindrome Linked List	Python | C++
  237.	Easy	Delete Node in a Linked List	Python | C++
  287.	Medium	Find the Duplicate Number	Python
  328.	Medium	Odd Even Linked List	Python
  445.	Medium	Add Two Numbers II	Python
  707.	Medium	Design Linked List	Python
  771.	Easy	Jewels and Stones	Python
  876.	Easy	Middle of the Linked List	Python | C++
  1290.	Easy	Convert Binary Number in a Linked List to Integer	Python | Java

• Math

  Sl No.	Level	Questions	Solution
  258.	Easy	Add Digits	Python

• Minimax

  Sl No.	Level	Questions	Solution
  292.	Easy	Nim Game	Python

• Mock

  Sl No.	Level	Questions	Solution
  482.	Easy	License Key Formatting	Python

• Stack

  Sl No.	Level	Questions	Solution
  155.	Easy	Min Stack	Python
  1021.	Easy	Remove Outermost Parentheses	Python

• String

  Sl No.	Level	Questions	Solution
  49.	Medium	Group Anagrams	Python
  125.	Easy	Valid Palindrome	Python
  151.	Medium	Reverse Words in a String	Python
  242.	Easy	Valid Anagram	Python
  345.	Easy	Reverse Vowels of a String	Python
  383.	Easy	Ransom Note	Python
  468.	Medium	Validate IP Address	Python
  520.	Easy	Detect Capital	Python
  551.	Easy	Student Attendance Record I	Python | Java
  678.	Medium	Valid Parenthesis String)	Python
  709.	Easy	To Lower Case	Python | C | C++
  771.	Easy	Jewels and Stones	Python
  804.	Easy	Unique Morse Code Words	Python
  844.	Easy	Backspace String Compare	Python
  917.	Easy	Reverse Only Letters	Python
  925.	Easy	Long Pressed Name	Python
  1108.	Easy	Defanging an IP Address	Python | C++
  1189.	Easy	Maximum Number of Balloons	Python
  1427.	Easy	Perform String Shifts	Python

• Tree

  Sl No.	Level	Questions	Solution
  94.	Medium	Binary Tree Inorder Traversal	Python | C++ | Java
  98.	Medium	Validate Binary Search Tree	Python
  100.	Easy	Same Tree	Python
  101.	Easy	Symmetric Tree	Python
  102.	Medium	Binary Tree Level Order Traversal	Python
  104.	Easy	Maximum Depth of Binary Tree	Python | C | C++ | Java
  112.	Easy	Path Sum	Python
  144.	Medium	Binary Tree Preorder Traversal	Python
  145.	Hard	Binary Tree Postorder Traversal	Python
  226.	Easy	Invert Binary Tree	Python
  257.	Easy	Binary Tree Paths	Python
  543.	Easy	Diameter of Binary Tree	Python
  589.	Easy	N-ary Tree Preorder Traversal	Python
  590.	Easy	N-ary Tree Postorder Traversal	Python
  617.	Easy	Merge Two Binary Trees	Python
  700.	Easy	Search in a Binary Search Tree	Python
  872.	Easy	Leaf-Similar Trees	Python
  938.	Easy	Range Sum of BST	Python
  1022.	Easy	Sum of Root To Leaf Binary Numbers	Python

• April LeetCoding Challenge : 2020

  Day	Sl No.	Level	Questions	Solution
  1	136.	Easy	Single Number	Python
  2	202.	Easy	Happy Number	Python
  3	53.	Easy	Maximum Subarray	Python
  4	283.	Easy	Move Zeroes	Python
  5	122.	Easy	Best Time to Buy and Sell Stock II	Python
  6	49.	Medium	Group Anagrams	Python
  7	1426.	Easy	Counting Elements	Python
  8	876.	Easy	Middle of the Linked List	Python | C++
  9	844.	Easy	Backspace String Compare	Python
  10	155.	Easy	Min Stack	Python
  11	543.	Easy	Diameter of Binary Tree	Python
  12	1046.	Easy	Last Stone Weight	Python
  13	525.	Medium	Contiguous Array
  14	1427.	Easy	Perform String Shifts	Python
  15	238.	Medium	Product of Array Except Self	Python
  16	678.	Medium	Valid Parenthesis String	Python
  17	200.	Medium	Number of Islands
  18	64.	Medium	Minimum Path Sum	Python

• May LeetCoding Challenge : 2020

  Day	Sl No.	Level	Questions	Solution
  1	278.	Easy	278. First Bad Version	Python
  2	771.	Easy	Jewels and Stones	Python
  3	383.	Easy	Ransom Note	Python
  4	476.	Easy	Number Complement	Python
  5	387.	Easy	First Unique Character in a String	Python
  6	169.	Easy	Majority Element	Python
  8	1232.	Easy	Check If It Is a Straight Line	Python
  9	367.	Easy	Valid Perfect Square	Python
  12	540.	Medium	Single Element in a Sorted Array	Python
  22	451.	Medium	Sort Characters By Frequency	Python

• June LeetCoding Challenge : 2020

  Day	Sl No.	Level	Questions	Solution
  1	226.	Easy	Invert Binary Tree	Python
  2	237.	Easy	Delete Node in a Linked List	Python | C++
  3	1029.	Easy	Two City Scheduling	Python
  4	344.	Easy	Revese String	Python
  5	528.	Medium	Random Pick with Weight	Python
  8	231.	Easy	Power of Two	Python
  16	468.	Medium	Validate IP Address	Python

• July LeetCoding Challenge : 2020

  Day	Sl No.	Level	Questions	Solution
  1	441.	Easy	Arranging Coins	Python
  6	66.	Easy	Plus One	Python
  26	258.	Easy	Add Digits	Python

• August LeetCoding Challenge : 2020

  Day	Sl No.	Level	Questions	Solution
  1	520.	Easy	Detect Capital	Python
  2	705.	Easy	Design HashSet	Python
  2	125.	Easy	Valid Palindrome	Python
  3	342.	Easy	Power of Four	Python
  5	442.	Medium	Find All Duplicates in an Array	Python