LeetCode Algorithms

🔒 = Subscription Content

Problems

#	Name	Solution	Youtube
1	Two Sum
2	Add Two Numbers
3	Longest Substring Without Repeating Characters
5	Longest Palindromic Substring
6	Zigzag Conversion
7	Reverse Integer
8	String to Integer (atoi)
9	Palindrome Number
11	Container With Most Water
12	Integer to Roman
13	Roman To Integer
14	Longest Common Prefix
15	3Sum
16	3Sum Closest
17	Letter Combinations of a Phone Number
18	4Sum
19	Remove Nth Node From End of List
20	ValidParentheses
21	Merge 2 Sorted Lists
22	Generate Parentheses
24	Swap Nodes in Pairs
26	Remove Duplicates From Sorted Array
27	Remove Element
28	Needle in Haystack
29	Divide Two Integers
31	Next Permutation
33	Search in Rotated Sorted Array
34	Find First and Last Position of Element in Sorted Array
35	Search Inserted Position
36	Valid Sudoku
37	Sudoku Solver
38	Count and Say
39	Combination Sum
40	Combination Sum II
42	Trapping Rain Water
43	Multiply Strings
45	Jump Game II
46	Permutations
47	Permutations II
48	Rotate Image
49	Group Anagrams
50	Pow(x,n)
53	Maximum SubArray
54	Spiral Matrix
55	Jump Game
56	Merge Intervals
57	Insert Interval
58	Length of Last Word
59	Spiral Matrix II
61	Rotate List
62	Unique Paths
63	Unique Paths II
64	Minimum Path Sum
66	Plus One
67	Add Binary
69	Sqrt(x)
70	Climbing Stairs
71	Simplify Path
73	Set Matrix Zeroes
74	Search a 2D Matrix
75	Sort Colors
77	Combinations
78	Subsets
79	Word Search
80	Remove Duplicates from Sorted Array II
81	Search in Rotated Sorted Array II
82	Remove Duplicates from Sorted List II
83	Remove Duplicates from Sorted List
86	Partition List
88	Merge Sorted Array
89	Gray Code
90	Subsets II
91	Decode Ways
92	Reverse Linked List II
93	Restore IP Addresses
94	Binary Tree Inorder Traversal
95	Unique Binary Search Trees II
96	Unique Binary Search Trees
97	Interleaving String
98	Validate Binary Search Tree
99	Recover Binary Search Tree
100	Same Tree
101	Symmetric Tree
102	Binary Tree Level Order Traversal
103	Binary Tree Zigzag Level Order Traversal
104	Maximum Depth of Binary Tree
105	Construct Binary Tree from Preorder and Inorder Traversal
106	Construct Binary Tree from Inorder and Postorder Traversal
107	Binary Tree Level Order Traversal II
108	Convert Sorted Array To Binary Search Tree
109	Convert Sorted List to Binary Search Tree
110	Balanced Binary Tree
111	Minimum Depth of Binary Tree
112	Path Sum
113	Path Sum II
114	Flatten Binary Tree to Linked List
116	Populating Next Right Pointers in Each Node
117	Populating Next Right Pointers in Each Node II
118	Pascal's Triangle
119	Pascal's Triangle II
120	Triangle
121	Best Time to Buy and Sell Stocks
122	Best Time to Buy and Sell Stocks II
125	Valid Palindrome
128	Longest Consecutive Sequence
129	Sum Root to Leaf Numbers
130	Surrounded Regions
131	Palindrome Partitioning
133	Clone Graph
134	Gas Station
136	Single Number
137	Single Number II
138	Copy List with Random Pointer
139	Word Break
141	Linked List Cycle
142	Linked List Cycle II
143	Reorder List
144	Binary Tree Preorder Traversal
145	Binary Tree Postorder Traversal
146	LRU Cache
147	Insertion Sort List
148	Sort List
150	Evaluate Reverse Polish Notation
151	Reverse Words in a String
152	Maximum Product Subarray
153	Find Minimum in Rotated Sorted Array
155	Min Stack
156	🔒 Binary Tree Upside Down
157	Read N Characters Given Read4
159	🔒 Longest Substring With At Most Two Distinct Characters
160	Intersection of Two Linked Lists
161	🔒 One Edit Distance
162	Find Peak Element
165	Compare Version Numbers
166	Fraction to Recurring Decimal
167	Two Sum II - Input Array is Sorted
168	Excel Sheet Column Title
169	Majority Element
170	🔒 Two Sum III - Data Structure Design
171	Excel Sheet Column Number
172	Factoring Trailing Zeroes
173	Binary Search Tree Iterator
179	Largest Number
187	Repeated DNA Sequences
189	Rotate Array
190	Reverse Bits
191	Number of One Bits
198	House Robber
199	Binary Tree Right Side View
200	Number of Islands
201	Bitwise AND of Numbers Range
202	Happy Number
203	Remove Linked List Elements
204	Count Primes
205	Isomorphic Strings
206	Reverse Linked List
207	Course Schedule
208	Implement Trie (Prefix Tree)
209	Minimum Size Subarray Sum
210	Course Schedule II
211	Design Add and Search Words Data Structure
213	House Robber II
215	Kth Largest Element in an Array
216	Combination Sum III
217	Contains Duplicate
219	Contains Duplicate II
220	Contains Duplicate III
221	Maximal Square
222	Count Complete Tree Nodes
223	Rectangle Area
225	Implement Stack using Queues
226	Invert Binary Tree
227	Basic Calculator II
229	Majority Element II
230	Kth Smallest Element in a BST
231	Power of Two
232	Implement Queue Using Stacks
234	Palindrome Linked Lists
235	Lowest Common Ancestor of a Binary Search Tree
236	Lowest Common Ancestor of a Binary Tree
237	Delete a Node In A Linked List
238	Product of Array Except Self
240	Search a 2D Matrix II
241	Different Ways to Add Parentheses
242	Valid Anagram
243	🔒 Shortest Word Distance
244	🔒 Shortest Word Distance II
245	🔒 Shortest Word Distance III
246	🔒 Strobogramatic Number
247	🔒 Strobogramatic Number II
249	🔒 Group Shifted Strings
250	🔒 Count Univalue Subtrees
251	🔒 Flatten 2D Vector
252	🔒 Meeting Rooms
253	🔒 Meeting Rooms II
254	🔒 Factor Combinations
255	🔒 Verify Preorder Sequence In Binary Search Tree
256	🔒 Paint House
257	Binary Tree Paths
258	Add Digits
259	🔒 3Sum Smaller
260	Single Number III
261	🔒 Graph Valid Tree
263	Ugly Number
264	Ugly Number II
266	🔒 Palindrome Permutation
267	🔒 Palindrome Permutation II
268	Missing Number
270	🔒 Closest Binary Search Tree Value
271	🔒 Encode and Decode Strings
274	H-Index
275	H-Index II
276	🔒 Paint Fence
277	🔒 Find The Celebrity
278	First Bad Version
279	Perfect Squares
280	🔒 Wiggle Sort
281	🔒 Zigzag Iterator
283	Move Zeroes
284	Peeking Iterator
285	🔒 Inorder Successor in BST
286	🔒 Walls and Gates
287	Find the Duplicate Number
288	🔒 Unique Word Abbreviation
289	Game of Life
290	Word Pattern
291	🔒 Word Pattern II
292	Nim Game
293	🔒 Flip Game
294	🔒 Flip Game II
298	🔒 Binary Tree Longest Consecutive Sequence
299	Bulls and Cows
300	Longest Increasing Subsequence
303	Range Sum Query - Immutable
304	Range Sum Query 2D - Immutable
306	Additive Number
307	Range Sum Query - Mutable
309	Best Time to Buy and Sell Stock with Cooldown
310	Minimum Height Trees
311	🔒 Sparse Matrix Multiplication
313	Super Ugly Number
314	🔒 Binary Tree Vertical Order Traversal
316	Remove Duplicate Letters
318	Maximum Product of Word Lengths
319	Bulb Switcher
320	🔒 Generalized Abbreviation
322	Coin Change
323	🔒 Number of Connected Components in Undirected Graph
324	Wiggle Sort II
325	🔒 Maximum Size Subarray Sum Equals K
326	Power of Three
328	Odd Even Linked List
331	Verify Preorder Serialization of a Binary Tree
331	🔒 Largest BST Subtree
334	Increasing Triplet Subsequence
337	House Robber III
338	Counting Bits
339	🔒 Nested List Weight Sum
340	🔒 Longest Substring with At Most K Distinct Characters
341	Flatten Nested List Iterator
342	Power of Four
343	Integer Break
344	Reverse A String
345	Reverse Vowels of A String
346	🔒 Moving Average From Data Stream
347	Top K frequent Elements
348	🔒 Design Tic-Tac-Toe
349	Intersection of 2 Arrays
350	Intersection of 2 Arrays II
351	🔒 Android Unlock Patterns
355	Design Twitter
357	Count Numbers with Unique Digits
359	🔒 Logger Rate Limiter
367	Valid Perfect Square
374	Guess Number Higher or Lower
383	Ransom Note
387	First Unique Character in String
389	Find the Difference
392	Is Subsequence
401	Binary Watch
404	Sum of Left Leaves
405	Convert a Number to Hexadecimal
408	🔒 Valid Word Abbreviation
409	Longest Palindrome
412	Fizz Buzz
414	Third Maximum Number
415	Add Strings
422	🔒 Valid Word Square
430	Flatten a Multilevel Doubly Linked List
434	Number of Segments in a String
441	Arranging Coins
443	String Compression
447	Number of Boomerangs
448	Find All Numbers Disappeared in an Array
453	Minimum Moves to Equal Array Elements
455	Assign Cookies
459	Repeated Substring Pattern
461	Hamming Distance
463	Island Perimeter
475	Heaters
476	Number Complement
482	License Key Formatting
485	Max Consecutive Ones
492	Construct the Rectangle
495	Teemo Attacking
496	Next Greater Element I
500	Keyboard Row
501	Find Mode in Binary Search Tree
504	Base 7
506	Relative Ranks
507	Perfect Number
509	Fibonacci Number
520	Detect Capital
521	Longest Uncommon Subsequence I
530	Minimum Absolute Difference in BST
532	K - Diff Pairs in Array
538	Convert BST to Greater Tree
541	Reverse String II
543	Diameter of Binary Tree
551	Student Attendance Record I
557	Reverse Words in a String III
559	Maximum Depth of N-Ary Tree
561	Array Partition I
563	Binary Tree Tilt
566	Reshape The Matrix
572	Subtree of Another Tree
575	Distribute Candies
581	Shortest Unsorted Continuous Subarray
589	N-Ary Tree Preorder Traversal
590	N-Ary Tree Postorder Traversal
594	Longest Harmonious Subsequence
598	Range Addition II
599	Minimum Index Sum of 2 Lists
604	🔒 Design Compressed String Iterator
605	Can Place Flowers
606	Construct String from Binary Tree
617	Merge Two Binary Trees
624	🔒 Maximum Distance in Arrays
628	Maximum Product of Three Numbers
633	Sum Square Numbers
637	Average of Levels in Binary Tree
643	Maximum Average SubArray I
645	Set Mismatch
653	Two Sum IV - Input is a BST
657	Robot Return to Origin
661	Image Smoother
665	Non Deceasing Array
669	Trim a Binary Search Tree
671	Second Minimum Node in Binary Tree
674	Longest Continuous Increasing Subsequence
680	Valid Palindrome II
682	Baseball Game
686	Repeated String Match
687	Longest Univalue Path
688	Knight Probability in Chessboard
690	Employee Importance
693	Binary Number with Alternating Bits
696	Count Binary Substrings
697	Degree of an Array
700	Search in a Binary Search Tree
703	Kth Largest Element in a Stream
704	Binary Search
705	Design HashSet
706	Design HashMap
709	To Lower Case
716	🔒 Max Stack
717	1-bit and 2-bit Characters
718	Maximum Length of Repeated Subarray
720	Longest Word in Dictionary
724	Find Pivot Index
728	Self Dividing Numbers
733	Flood Fill
743	Network Delay Time
734	Sentence Similarity
744	Find Smallest Letter Greater Than Target
746	Min Cost Climbing Stairs
747	Largest Number at least Twice of Others
748	Shortest Completing Word
758	Bold Words in String
760	Find Anagram Mappings
762	Prime Number of Set Bits in Primary Representation
766	Toeplitz Matrix
771	Jewels and Stones
783	Minimum Distance Between BST Nodes
788	Rotated Digits
796	Rotate String
800	Similar RGB Color
804	Unique Morse Code Words
806	Number of Lines to Write String
811	Subdomain Visit Count
812	Largest Triangle Area
819	Most Common Word
821	Shortest Distance to Character
824	Goat Latin
830	Positions of Large Groups
832	Flipping an Image
836	Rectangle Overlap
840	Magic Squares in Grid
844	Backspace String Compare
849	Maximize Distance to Closest Person
852	Peak Index in Mountain Array
859	Buddy Strings
860	Lemonade Change
867	Transpose Matrix
868	Binary Gap
872	Leaf-Similar Trees
874	Walking Robot Simulation
876	Middle of the Linked List
883	Projection Area of 3D Shapes
884	Uncommon Words from 2 Sentences
888	Fair Candy Swap
892	Surface Area of 3D Shapes
893	Groups of Special Equivalent Strings
896	Monotonic Array
897	Increasing Order Search Tree
905	Sort Array by Parity
908	Smallest Range I
914	X of a kind in a Deck of Cards
917	Reverse Only Letters
922	Sort Array by Parity II
925	Long Pressed Name
929	Unique Email Addresses
933	Number of Recent Calls
937	Reorder Data In Log Files
938	Range Sum of BST
941	Valid Mountain Array
942	DI String Match
944	Delete Columns to Make Sorted
949	Largest Time for Given Digits
953	Verifying an Alien Dictionary
961	N-Repeated Elements in Size 2N Array
965	Univalued Binary Tree
970	Powerful Integers
976	Largest Perimeter Triangle
977	Squares of a Sorted Array
985	Sum of Even Numbers after Queries
989	Add to Array Form of Integer
993	Cousins in Binary Tree
994	Rotting Oranges
997	Find the Town Judge
999	Available Captures for Rook
1002	Find Common Characters
1005	Maximize Sum of Array After K Negations
1009	Complement of Base 10 Integer
1010	Pairs of Songs With Total Durations Divisible by 60
1013	Partition Array into Three Parts with equal Sum
1018	Binary Prefix Divisible by 5
1021	Remove Outermost Parenthesis
1022	Sum of Root to Leaf Binary Numbers
1025	Divisor Game
1029	Two City Scheduling
1030	Matrix Cells in Distance Order
1033	Moving Stones Until Consecutive
1037	Valid Boomerang
1042	Flower Planting with no Adjacent
1046	Last Stone Weight
1047	Remove All adjacent Duplicates in String
1051	Height Checker
1056	🔒 Confusing Number
1064	🔒 Fixed Point
1065	🔒 Index Pairs of a String
1071	Greatest Common Divisors of Strings
1078	Occurrence After Bigram
1085	🔒 Sum of Digits in Minimum Number
1086	🔒 High Five
1089	Duplicate Zeroes
1099	🔒 Two Sum Less Than K
1103	Distribute Candies to People
1108	Defanging an IP Address
1118	🔒 Number of Days in a Month
1119	🔒 Remove Vowels From String
1122	Relative Sort Array
1128	Number of Equivalent Domino Pairs
1133	🔒 Largest Unique Number
1134	🔒 Armstrong Number
1137	Nth Tribonacci Number
1143	Longest Common Subsequence
1150	Check if Number is Majority Element in Sorted Array
1154	Day of The Year
1160	Find Words That Can Be Formed By Characters
1165	Single Row Keyboard
1170	Compare Strings By Frequency of the Smallest Character
1175	Prime Arrangements
1176	🔒 Diet Plan Performance
1180	🔒 Count Substrings with only one Distinct Letter
1184	Distance Between Bus Stops
1185	Day of the Week
1189	Maximum Number of Balloons
1196	🔒 How Many Apples Can You Put into the Basket
1200	Minimum Absolute Difference
1201	Ugly Number III
1207	Unique Number of Occurrences
1213	🔒 Intersection of Three Sorted Arrays
1217	Minimum Cost to Move Chips to The Same Position
1221	Split A String In Balanced Strings
1228	🔒 Missing A Number In Arithmetic Progression
1232	Check If It Is A Straight Line
1237	Find Positive Integer Solutions for a Given Equation
1243	🔒 Array Transformation
1249	Minimum Remove to Make Valid Parentheses
1252	Cells With Odd Values In Matrix
1260	Shift 2D Grid
1266	Minimum Time Visiting All Points
1271	🔒 Hexspeak
1275	Find Winner On a Tic Tac Toe Game
1281	Subtract the Product and Sum of Digits of a Integer
1287	Element Appearing More Than 25% in Sorted Array
1290	Convert Binary Number In A Linked List to Integer
1295	Find Numbers With Even Numbers of Digits
1299	Replace Elements With Greatest Element on Right Side
1304	Find N Unique Integers Sum Up To Zero
1309	Decrypt String From Alphabet To Integer Mapping
1313	Decompress Run-Length Encoded Strings
1317	Convert Integer to Sum Of Two Non-Zero Integers
1323	Maximum 69 Number
1331	Rank Transform of An Array
1332	Remove Palindromic Subsequences
1337	The K Weakest Rows In A Matrix
1342	Number of Steps to Reduce a Number to Zero
1346	Check if N and It's Double Exist
1351	Count Negative Numbers In A Sorted Matrix
1356	Sort Integers by Number of 1 Bits
1360	Number of Days Between Two Dates
1365	How Many Numbers Are Smaller Than Current Number
1370	Increasing Decreasing String
1374	Generate A String With Characters That Have Odd Count
1376	Time Needed to Inform All Employees
1380	Lucky Numbers In A Matrix
1385	Find The Distance Value Between 2 Arrays
1389	Create Target Array in Given Order
1394	Find Lucky Integer In An Array
1399	Count Largest Group
1403	Minimum Subsequence in Non-Increasing Order
1408	String Matching In An Array
1413	Minimum Value To Get Positive Step By Step Sum
1417	Reformat The String
1422	Maximum Score After Splitting A String
1426	🔒 Counting Elements
1427	🔒 Performing String Shifts
1431	Kids With The Greatest Number Of Candies
1436	Destination City
1437	Check If All 1's Are at Least Length K Places Away
1441	Build An Array With Stack Operation
1446	Consecutive Characters
1450	Number of Students Doing Homework at Given Time
1455	Check If Word Occurs as Prefix of any Word in Sentence
1460	Make 2 Arrays Equal by Reversing Sub Arrays
1464	Maximum Product of 2 Elements in Array
1469	🔒 Find All Lonely Nodes
1470	Shuffle The Array
1474	Delete N Nodes After M Nodes In A Linked List
1475	Final Prices With Special Discount in a Shop
1480	Running Sum of 1D Array
1486	XOR Operations in An Array
1491	Average Salary Excluding the Minimum and Maximum Salary
1496	Path Crossing
1502	Can Make Arithmetic Progression From Sequence
1507	Reformat Date
1512	Number of Good Pairs
1518	Water Bottles
1523	Count Odd Numbers In Interval Range
1528	Shuffle Strings
1534	Count Good Triplets
1539	Kth Missing Positive Number
1544	Make The String Great
1550	Three Consecutive Odds
1556	Thousand Separator
1560	Most Visited Sector in a Circular Track
1566	Detect Pattern of Length M Repeated K or More Times
1572	Matrix Diagonal Sum
1576	Replace All ?'s to Avoid Consecutive Repeating Characters
1582	Special Positions in a Binary Matrix
1588	Sum of All Odd Length Subarrays
1592	Rearrange Spaces Between Words
1598	Crawler Log Folder
1600	Throne Inheritance
1603	Design Parking System
1608	Special Array With X Elements Greater Than or Equal X
1614	Maximum Nesting Depth of the Parentheses
1619	Mean of Array After Removing Some Elements
1624	Largest Substring Between Two Equal Characters
1629	Slowest Key
1636	Sort Array by Increasing Frequency
1640	Check Array Formation Through Concatenation
1646	Get Maximum in Generated Array
1652	Defuse the Bomb
1656	Design an Ordered Stream
1662	Check If Two String Arrays are Equivalent
1668	Maximum Repeating Substring
1672	Richest Customer Wealth
1678	Goal Parser Interpretation
1684	Count the Number of Consistent Strings
1688	Count of Matches in Tournament
1694	Reformat Phone Number
1700	Number of Students Unable to Eat Lunch
1704	Determine if String Halves Are Alike
1708	🔒 Largest Subarray Length K
1710	Maximum Units on a Truck
1716	Calculate Money in Leetcode Bank
1720	Decode XORed Array
1725	Number Of Rectangles That Can Form The Largest Square
1732	Find the Highest Altitude
1736	Latest Time by Replacing Hidden Digits
1742	Maximum Number of Balls in a Box
1748	Sum of Unique Elements
1752	Check if Array Is Sorted and Rotated
1758	Minimum Changes To Make Alternating Binary String
1763	Longest Nice Substring
1768	Merge Strings Alternately
1773	Count Items Matching a Rule
1779	Find Nearest Point That Has the Same X or Y Coordinate
1784	Check if Binary String Has at Most One Segment of Ones
1790	Check if One String Swap Can Make Strings Equal
1791	Find Center of Star Graph
1796	Second Largest Digit in a String
1800	Maximum Ascending Subarray Sum
1805	Number of Different Integers in a String
1812	Determine Color of a Chessboard Square
1816	Truncate Sentence
1822	Sign of the Product of an Array
1826	🔒 Faulty Sensor
1827	Minimum Operations to Make the Array Increasing
1832	Check if the Sentence Is Pangram
1837	Sum of Digits in Base K
1844	Replace All Digits with Characters
1848	Minimum Distance to the Target Element
1854	Maximum Population Year
1859	Sorting the Sentence
1863	Sum of All Subset XOR Totals
1869	Longer Contiguous Segments of Ones than Zeros
1876	Substrings of Size Three with Distinct Characters
1880	Check if Word Equals Summation of Two Words
1886	Determine Whether Matrix Can Be Obtained By Rotation
1893	Check if All the Integers in a Range Are Covered
1897	Redistribute Characters to Make All Strings Equal
1903	Largest Odd Number in String
1909	Remove One Element to Make the Array Strictly Increasing
1913	Maximum Product Difference Between Two Pairs
1920	Build Array from Permutation
1925	Count Square Sum Triples
1929	Concatenation of Array
1933	🔒 Check If String Is Decomposable Into Value EqualSubstrings
1935	Maximum Number of Words You Can Type
1941	Check if All Characters Have Equal Number of Occurrences
1945	Sum of Digits of String After Convert
1952	Three Divisors
1957	Delete Characters to Make Fancy String
1961	Check If String Is a Prefix of Array
1967	Number of Strings That Appear as Substrings in Word
1971	Find if Path Exists in Graph
1974	Minimum Time to Type Word Using Special Typewriter
1979	Find Greatest Common Divisor of Array
1984	Minimum Difference Between Highest and Lowest of K Scores
1991	Find the Middle Index in Array
1995	Count Special Quadruplets
2000	Reverse Prefix of Word
2006	Count Number of Pairs With Absolute Difference K
2011	Final Value of Variable After Performing Operations
2016	Maximum Difference Between Increasing Elements
2022	Convert 1D Array Into 2D Array
2027	Minimum Moves to Convert String
2032	Two Out of Three
2037	Minimum Number of Moves to Seat Everyone
2042	Check if Numbers Are Ascending in a Sentence
2047	Number of Valid Words in a Sentence
2053	Kth Distinct String in an Array
2057	Smallest Index With Equal Value
2062	Count Vowel Substrings of a String
2068	Check Whether Two Strings are Almost Equivalent
2073	Time Needed to Buy Tickets
2078	Two Furthest Houses With Different Colors
2085	Count Common Words With One Occurrence
2089	Find Target Indices After Sorting Array
2094	Finding 3-Digit Even Numbers
2099	Find Subsequence of Length K With the Largest Sum
2103	Rings and Rods
2108	Find First Palindromic String in the Array