README.md

Algorithms

ID	Blog	Solutions	Diffculty	Tags
48	Rotate Image	1 .py	MEDIUM	MATH
1299	Replace Elements with Greatest Element on Right Side	1 .cpp	EASY	ARRAY
1360	Number of Days Between Two Dates	1 .cpp	EASY	DATE
1213	Intersection of Three Sorted Arrays	2 .py .cpp
199	Binary Tree Right Side View	1 .py	MEDIUM	DFS
151	Reverse Words in a String	1 .cpp	MEDIUM	STRING
2521	Distinct Prime Factors of Product of Array	2 .py .rs	MEDIUM	MATH
1491	Average Salary Excluding the Minimum and Maximum Salary	2 .py .cpp	EASY	MATH
96	Unique Binary Search Trees	1 .py	MEDIUM	MATH DP
452	Minimum Number of Arrows to Burst Balloons	1 .py	MEDIUM	GREEDY
359	Logger Rate Limiter	2 .cpp .java
593	Valid Square	2 .cpp .java
307	Range Sum Query - Mutable	1 .py	MEDIUM	MATH SQRT DECOMPOSITION
762	Prime Number of Set Bits in Binary Representation	2 .py .cpp
557	Reverse Words in a String III	3 .cpp .java
1523	Count Odd Numbers in an Interval Range	1 .py	EASY	MATH
11	Container With Most Water	1 .py	MEDIUM	MATH TWO POINTER
2716	Minimize String Length	1 .py	EASY	HASH MAP
1134	Armstrong Number	1 .py
1903	Largest Odd Number in String	1 .py	EASY	GREEDY STRING
1218	Longest Arithmetic Subsequence of Given Difference	1 .cpp
1325	Delete Leaves With a Given Value	1 .java	MEDIUM	RECURSION BINARY TREE DFS
110	Balanced Binary Tree	1 .cpp	EASY	RECURSION BINARY TREE
647	Palindromic Substrings	2 .cpp
2506	Count Pairs Of Similar Strings	1 .rs	EASY	MATH HASH MAP
1492	The kth Factor of n	1 .cpp	MEDIUM
1304	Find N Unique Integers Sum up to Zero	1 .py	EASY	MATH
2409	Count Days Spent Together	1 .py	MEDIUM	LINE SWEEP
443	String Compression	1 .cpp
357	Count Numbers with Unique Digits	1 .py	MEDIUM	DP
1812	Determine Color of a Chessboard Square	1 .cpp	EASY	MATH
559	Maximum Depth of N-ary Tree	1 .py	EASY	BFS
350	Intersection of Two Arrays II	4 .cpp .js .java
1832	Check if the Sentence Is Pangram	1 .py	EASY	STRING HASH MAP
986	Interval List Intersections	1 .cpp	MEDIUM	TWO POINTER
120	Triangle	1 .py	MEDIUM	DP
1046	Last Stone Weight	1 .java	EASY	PRIORITY QUEUE
1215	Stepping Numbers	1 .cpp
1275	Find Winner on a Tic Tac Toe Game	1 .cpp	EASY	BRUTEFORCE GAME
1930	Unique Length-3 Palindromic Subsequences	1 .py	MEDIUM	HASH MAP
1658	Minimum Operations to Reduce X to Zero	1 .py	MEDIUM	TWO POINTER SLIDING WINDOW
576	Out of Boundary Paths	1 .py	MEDIUM	RECURSION DP MEMOIZATION
1099	Two Sum Less Than K	2 .cpp
448	Find All Numbers Disappeared in an Array	1 .py	EASY	HASH MAP
73	Set Matrix Zeroes	1 .py	MEDIUM	HASH MAP
108	Convert Sorted Array to Binary Search Tree	2 .cpp	EASY	RECURSION BINARY TREE
500	Keyboard Row	1 .py	EASY	HASH MAP
1710	Maximum Units on a Truck	1 .cpp	EASY	GREEDY
758	Bold Words in String	1 .cpp
654	Maximum Binary Tree	2 .cpp
1342	Number of Steps to Reduce a Number to Zero	2 .py .cpp	EASY	MATH
1253	Reconstruct a 2-Row Binary Matrix	1 .cpp	MEDIUM	GREEDY
961	N-Repeated Element in Size 2N Array	12 .js .java .cpp .py .php
1558	Minimum Numbers of Function Calls to Make Target Array	1 .cpp	MEDIUM	MATH
504	Base 7	3 .cpp
171	Excel Sheet Column Number	1 .py	EASY
1470	Shuffle the Array	1 .go	EASY	ARRAY
1110	Delete Nodes And Return Forest	1 .cpp
1085	Sum of Digits in the Minimum Number	4 .py .cpp
2605	Form Smallest Number From Two Digit Arrays	1 .py	EASY	SET
1886	Determine Whether Matrix Can Be Obtained By Rotation	1 .py	EASY	MATH
1816	Truncate Sentence	1 .py	EASY	STRING
912	Sort an Array	3 .py .cpp .js
254	Factor Combinations	3 .py .cpp	MEDIUM	DFS
1315	Sum of Nodes with Even-Valued Grandparent	1 .java	MEDIUM	RECURSION DFS
1506	Find Root of N-Ary Tree	1 .cpp	MEDIUM	HASH MAP
1472	Design Browser History	1 .cpp	MEDIUM	DEQUE
560	Subarray Sum Equals K	4 .cpp
1207	Unique Number of Occurrences	1 .cpp
56	Merge Intervals	1 .py	MEDIUM	MATH
148	Sort List	1 .cpp	MEDIUM	RECURSION DIVIDE-AND-CONQUER SORTING
1457	Pseudo-Palindromic Paths in a Binary Tree	2 .py	MEDIUM	BFS DFS
2220	Minimum Bit Flips to Convert Number	1 .py	EASY	MATH
111	Minimum Depth of Binary Tree	1 .cpp	EASY	RECURSION DFS
860	Lemonade Change	1 .cpp
970	Powerful Integers	1 .cpp
2733	Neither Minimum nor Maximum	1 .py	EASY	MATH
1602	Find Nearest Right Node in Binary Tree	1 .cpp	MEDIUM	BFS
113	Path Sum II	2 .js	MEDIUM	RECURSION QUEUE DFS BINARY TREE BFS
1410	HTML Entity Parser	1 .cpp	MEDIUM	STRING
1180	Count Substrings with Only One Distinct Letter	4 .cpp
121	Best Time to Buy and Sell Stock	1 .py	EASY	MATH
3083	Existence of a Substring in a String and Its Reverse	1 .py	EASY	HASH MAP
679	24 Game	1 .cpp
747	Largest Number At Least Twice of Others	1 .cpp
1362	Closest Divisors	1 .cpp	MEDIUM	MATH
2293	Min Max Game	1 .py	EASY	RECURSION
572	Subtree of Another Tree	2 .cpp
513	Find Bottom Left Tree Value	1 .py	MEDIUM	BFS
742	Closest Leaf in a Binary Tree	1 .py	MEDIUM	BFS DFS GRAPH
2848	Points That Intersect With Cars	1 .py	EASY	LINE SWEEP
1443	Minimum Time to Collect All Apples in a Tree	1 .cpp	MEDIUM	DFS TREE
1190	Reverse Substrings Between Each Pair of Parentheses	1 .cpp
733	Flood Fill	2 .cpp
2352	Equal Row and Column Pairs	1 .py	MEDIUM	HASH MAP
1909	Remove One Element to Make the Array Strictly Increasing	1 .py	EASY	MATH BINARY SEARCH
1380	Lucky Numbers in a Matrix	1 .cpp	EASY	MATRIX
438	Find All Anagrams in a String	2 .py .cpp
1175	Prime Arrangements	1 .cpp
26	Remove Duplicates from Sorted Array	1 .py	EASY	TWO POINTER
536	Construct Binary Tree from String	1 .cpp
328	Odd Even Linked List	1 .cpp	MEDIUM	LINKED LIST
1768	Merge Strings Alternately	1 .go	EASY	TWO POINTER
31	Next Permutation	1 .cpp
941	Valid Mountain Array	2 .cpp .java
1854	Maximum Population Year	1 .cpp	EASY	LINE SWEEP
1374	Generate a String With Characters That Have Odd Counts	1 .py	EASY	STRING
131	Palindrome Partitioning	1 .cpp	MEDIUM	DFS
340	Longest Substring with At Most K Distinct Characters	1 .cpp	HARD	TWO POINTER SLIDING WINDOW
791	Custom Sort String	2 .cpp
1469	Find All the Lonely Nodes	1 .cpp	EASY	DFS
1200	Minimum Absolute Difference	2 .py .cpp	EASY	SORTING
3128	Right Triangles	1 .py	MEDIUM	MATH HASH MAP
515	Find Largest Value in Each Tree Row	2 .cpp
2006	Count Number of Pairs With Absolute Difference K	1 .py	EASY	HASH MAP
377	Combination Sum IV	1 .py	MEDIUM	DP
1006	Clumsy Factorial	1 .cpp
2160	Minimum Sum of Four Digit Number After Splitting Digits	1 .py	EASY	MATH
2129	Capitalize the Title	1 .py	EASY	TWO POINTER
2124	Check if All A's Appears Before All B's	1 .py	EASY	STRING
1694	Reformat Phone Number	1 .py	EASY	STRING
387	First Unique Character in a String	1 .py	EASY	HASH MAP
1027	Longest Arithmetic Sequence	1 .cpp	MEDIUM	DP
973	K Closest Points to Origin	2 .cpp .java
215	Kth Largest Element in an Array	2 .cpp	MEDIUM	PARTITION ARRAY BINARY SEARCH
2316	Count Unreachable Pairs of Nodes in an Undirected Graph	2 .py	MEDIUM	BFS DFS GRAPH
1290	Convert Binary Number in a Linked List to Integer	1 .cpp	EASY	LINKED LIST BINARY NUMBER
2446	Determine if Two Events Have Conflict	1 .py	EASY	MATH
594	Longest Harmonious Subsequence	1 .cpp	EASY	HASH MAP
896	Monotonic Array	2 .cpp
1260	Shift 2D Grid	1 .cpp	EASY	GRID SIMULATION
797	All Paths From Source to Target	1 .py	MEDIUM	DFS GRAPH
2728	Count Houses in a Circular Street	1 .rs	EASY	DESIGN
1021	Remove Outermost Parentheses	1 .cpp
543	Diameter of Binary Tree	1 .cpp	EASY	RECURSION DFS
451	Sort Characters By Frequency	2 .cpp
2259	Remove Digit From Number to Maximize Result	1 .py	EASY	BRUTEFORCE
518	Coin Change 2	1 .cpp
537	Complex Number Multiplication	2 .js .cpp
1037	Valid Boomerang	3 .cpp
2824	Count Pairs Whose Sum is Less than Target	1 .py	EASY	TWO POINTER
1314	Matrix Block Sum	1 .cpp	MEDIUM	DP
106	Construct Binary Tree from Inorder and Postorder Traversal	2 .cpp
186	Reverse Words in a String II	2 .cpp
1143	Longest Common Subsequence	1 .cpp	MEDIUM	DP
1167	Minimum Cost to Connect Sticks	2 .py .cpp
1128	Number of Equivalent Domino Pairs	1 .cpp
77	Combinations	1 .py	MEDIUM	BITMASK
117	Populating Next Right Pointers in Each Node II	1 .py	MEDIUM	BFS
89	Gray Code	1 .py	MEDIUM	MATH RECURSION
2578	Split With Minimum Sum	3 .py	EASY	GREEDY MATH HEAP PRIORITY QUEUE SORTING
806	Number of Lines to Write String	3 .cpp .java
1080	Insufficient Nodes in Root to Leaf Paths	1 .java
1365	How Many Numbers Are Smaller Than the Current Number	1 .cpp	EASY	BINARY SEARCH
206	Reverse Linked List	1 .js	EASY	RECURSION LINKED LIST
1456	Maximum Number of Vowels in a Substring of Given Length	1 .py	MEDIUM	SLIDING WINDOW
476	Number Complement	5 .cpp .js .java
1612	Check If Two Expression Trees are Equivalent	1 .cpp	MEDIUM	DFS
409	Longest Palindrome	2 .py .cpp	EASY	HASH MAP
392	Is Subsequence	1 .cpp
814	Binary Tree Pruning	2 .cpp
905	Sort Array By Parity	4 .cpp
1680	Concatenation of Consecutive Binary Numbers	1 .cpp	MEDIUM	MATH
2833	Furthest Point From Origin	1 .py	EASY	MATH HASH MAP
671	Second Minimum Node In a Binary Tree	5 .java
160	Intersection of Two Linked Lists	1 .cpp
1248	Count Number of Nice Subarrays	1 .java	MEDIUM	PREFIX SUM
2133	Check if Every Row and Column Contains All Numbers	1 .py	EASY	MATH
681	Next Closest Time	1 .cpp
2855	Minimum Right Shifts to Sort the Array	1 .py	EASY	ARRAY
22	Generate Parentheses	2 .cpp
661	Image Smoother	2 .cpp .java
1230	Toss Strange Coins	1 .cpp
98	Validate Binary Search Tree	1 .py	MEDIUM	RECURSION
1572	Matrix Diagonal Sum	1 .py	EASY	MATH
1973	Count Nodes Equal to Sum of Descendants	1 .py	MEDIUM	RECURSION DFS
856	Score of Parentheses	4 .cpp
2331	Evaluate Boolean Binary Tree	1 .py	EASY	RECURSION DFS
1338	Reduce Array Size to The Half	1 .py	MEDIUM	HASH MAP
230	Kth Smallest Element in a BST	9 .py .cpp .java	MEDIUM	RECURSION
1379	Find a Corresponding Node of a Binary Tree in a Clone of That Tree	1 .py	EASY	DFS
1566	Detect Pattern of Length M Repeated K or More Times	1 .py	EASY	BRUTEFORCE
2427	Number of Common Factors	1 .py	EASY	MATH GCD
1160	Find Words That Can Be Formed by Characters	1 .cpp
844	Backspace String Compare	3 .cpp .js .java
2490	Circular Sentence	1 .py	EASY	STRING
37	Sudoku Solver	1 .cpp	HARD	DFS BACKTRACKING
709	To Lower Case	3 .cpp .c
482	License Key Formatting	2 .cpp
441	Arranging Coins	1 .py	EASY	MATH
2652	Sum Multiples	1 .py	EASY	MATH
889	Construct Binary Tree from Preorder and Postorder Traversal	1 .cpp	MEDIUM	RECURSION
2481	Minimum Cuts to Divide a Circle	1 .py	EASY	MATH
507	Perfect Number	2 .cpp
1122	Relative Sort Array	3 .cpp
144	Binary Tree Preorder Traversal	1 .rs	EASY	RECURSION DFS
393	UTF-8 Validation	1 .cpp
1791	Find Center of Star Graph	1 .py	MEDIUM	GRAPH
1035	Uncrossed Lines	2 .py	MEDIUM	DP
1550	Three Consecutive Odds	1 .py	EASY	MATH ARRAY
416	Partition Equal Subset Sum	1 .cpp	MEDIUM	DP DFS
706	Design HashMap	1 .py	MEDIUM	DESIGN
1447	Simplified Fractions	1 .py	MEDIUM	MATH GCD
434	Number of Segments in a String	2 .py .cpp
628	Maximum Product of Three Numbers	2 .cpp
1404	Number of Steps to Reduce a Number in Binary Representation to One	1 .cpp	EASY	BINARY
9	Palindrome Number	1 .cpp	EASY
3168	Minimum Number of Chairs in a Waiting Room	1 .py	EASY	PREFIX SUM
270	Closest Binary Search Tree Value	1 .py	MEDIUM	BINARY SEARCH
1941	Check if All Characters Have Equal Number of Occurrences	1 .go	EASY	HASH MAP
94	Binary Tree Inorder Traversal	1 .py	EASY	RECURSION DFS
2348	Number of Zero-Filled Subarrays	1 .py	MEDIUM	MATH
366	Find Leaves of Binary Tree	3 .py .cpp .java	MEDIUM	DFS
987	Vertical Order Traversal of a Binary Tree	1 .cpp
139	Word Break	1 .py	MEDIUM	DFS
1503	Last Moment Before All Ants Fall Out of a Plank	1 .py	MEDIUM	MATH
2520	Count the Digits That Divide a Number	1 .py	EASY	MATH
874	Walking Robot Simulation	1 .cpp	EASY	SIMULATION HASH MAP
994	Rotting Oranges	1 .cpp	EASY	BFS
1196	How Many Apples Can You Put into the Basket	1 .cpp
280	Wiggle Sort	2 .cpp
895	Maximum Frequency Stack	1 .cpp	HARD	STACK HASH MAP
342	Power of Four	2 .cpp
2185	Counting Words With a Given Prefix	1 .py	EASY	STRING
1022	Sum of Root To Leaf Binary Numbers	2 .cpp .java
1118	Number of Days in a Month	1 .cpp
3211	Generate Binary Strings Without Adjacent Zeros	1 .py	MEDIUM	RECURSION DFS
329	Longest Increasing Path in a Matrix	1 .py	HARD	DP
842	Split Array into Fibonacci Sequence	1 .cpp
606	Construct String from Binary Tree	1 .cpp
922	Sort Array By Parity II	3 .cpp
582	Kill Process	2 .cpp
508	Most Frequent Subtree Sum	1 .cpp
914	X of a Kind in a Deck of Cards	1 .py	EASY	MATH GCD
2869	Minimum Operations to Collect Elements	1 .py	EASY	SET HASH MAP
1748	Sum of Unique Elements	1 .py	EASY	MATH
872	Leaf-Similar Trees	1 .py	EASY	DFS
1003	Check If Word Is Valid After Substitutions	1 .cpp	MEDIUM	STACK
1805	Number of Different Integers in a String	1 .py	EASY	STRING
1869	Longer Contiguous Segments of Ones than Zeros	1 .py	EASY	GROUPBY
538	Convert BST to Greater Tree	2 .cpp
908	Smallest Range I	1 .cpp
266	Palindrome Permutation	2 .cpp
2149	Rearrange Array Elements by Sign	1 .py	MEDIUM	ARRAY
252	Meeting Rooms	2 .cpp
477	Total Hamming Distance	1 .cpp
680	Valid Palindrome II	1 .cpp
219	Contains Duplicate II	1 .py	MEDIUM	SLIDING WINDOW
2309	Greatest English Letter in Upper and Lower Case	1 .py	EASY	STRING
2164	Sort Even and Odd Indices Independently	1 .py	EASY	SORTING
5087	Letter Tile Possibilities	1 .cpp
1018	Binary Prefix Divisible By 5	2 .cpp .java
1614	Maximum Nesting Depth of the Parentheses	1 .cpp	EASY	STRING
2436	Minimum Split Into Subarrays With GCD Greater Than One	1 .py	MEDIUM	GREEDY
33	Search in Rotated Sorted Array	2 .cpp .java
811	Subdomain Visit Count	2 .cpp
167	Two Sum II - Input array is sorted	1 .py	EASY	TWO POINTER
2094	Finding 3-Digit Even Numbers	1 .py	EASY	MATH
1935	Maximum Number of Words You Can Type	1 .py	EASY	HASH MAP
13	Roman to Integer	2 .cpp
1339	Maximum Product of Splitted Binary Tree	1 .py	MEDIUM	DFS
1302	Deepest Leaves Sum	2 .cpp	MEDIUM	BFS DFS
2287	Rearrange Characters to Make Target String	1 .py	EASY	HASH MAP
993	Cousins in Binary Tree	2 .cpp
34	Find First and Last Position of Element in Sorted Array	3 .cpp .js
1481	Least Number of Unique Integers after K Removals	1 .py	MEDIUM	HASH MAP
821	Shortest Distance to a Character	2 .cpp
3114	Latest Time You Can Obtain After Replacing Characters	1 .py	EASY	DECISION TREE
1884	Egg Drop With 2 Eggs and N Floors	1 .py	MEDIUM	DP
55	Jump Game	1 .cpp	MEDIUM	GREEDY
2579	Count Total Number of Colored Cells	1 .py	MEDIUM	MATH
663	Equal Tree Partition	1 .py	MEDIUM	DFS
845	Longest Mountain in Array	1 .cpp	MEDIUM	ARRAY
783	Minimum Distance Between BST Nodes	1 .py	EASY	RECURSION DFS
311	Sparse Matrix Multiplication	1 .cpp
1295	Find Numbers with Even Number of Digits	1 .cpp	EASY	ARRAY
3	Longest Substring Without Repeating Characters	1 .py	MEDIUM	TWO POINTER SLIDING WINDOW
1087	Brace Expansion	2 .cpp
21	Merge Two Sorted Lists	4 .cpp
216	Combination Sum III	1 .py	MEDIUM	MATH DFS
1344	Angle Between Hands of a Clock	1 .cpp	MEDIUM	GEOMETRY
159	Longest Substring with At Most Two Distinct Characters	1 .cpp	MEDIUM	TWO POINTER SLIDING WINDOW HASH MAP
27	Remove Element	1 .py	EASY	TWO POINTER
1474	Delete N Nodes After M Nodes of a Linked List	1 .cpp	EASY	LINKED LIST
869	Reordered Power of 2	1 .py	MEDIUM	MATH PERMUTATION
1352	Product of the Last K Numbers	1 .cpp
637	Average of Levels in Binary Tree	3 .cpp
2923	Find Champion I	1 .py	EASY	GRAPH
2571	Minimum Operations to Reduce an Integer to 0	4 .py .rs	MEDIUM	GREEDY RECURSION MATH BINARY DP
189	Rotate Array	1 .py	MEDIUM	ARRAY
883	Projection Area of 3D Shapes	1 .cpp
929	Unique Email Addresses	3 .js .cpp	MEDIUM	HASH MAP
1528	Shuffle String	1 .py	EASY	STRING
43	Multiply Strings	1 .java	MEDIUM	ARRAY
2810	Faulty Keyboard	1 .py	EASY	QUEUE
1704	Determine if String Halves Are Alike	1 .cpp	EASY	STRING
1317	Convert Integer to the Sum of Two No-Zero Integers	1 .java	EASY	BRUTEFORCE
384	Shuffle an Array	1 .py	MEDIUM	RANDOM
1929	Concatenation of Array	1 .py	EASY	ARRAY
362	Design Hit Counter	2 .cpp
2549	Count Distinct Numbers on Board	1 .py	EASY	MATH
1502	Can Make Arithmetic Progression From Sequence	1 .cpp	EASY	SORTING
276	Paint Fence	2 .py .cpp
1008	Construct Binary Search Tree from Preorder Traversal	3 .cpp .java
339	Nested List Weight Sum	1 .cpp
1356	Sort Integers by The Number of 1 Bits	1 .cpp	EASY	BIT HACKS SORTING
2558	Take Gifts From the Richest Pile	1 .py	EASY	HEAP
325	Maximum Size Subarray Sum Equals k	5 .cpp
938	Range Sum of BST	2 .cpp
394	Decode String	1 .cpp
2595	Number of Even and Odd Bits	1 .py	EASY	MATH BINARY
38	Count and Say	1 .py	MEDIUM	RECURSION
1800	Maximum Ascending Subarray Sum	1 .py	EASY	GREEDY
1188	Design Bounded Blocking Queue	1 .py	MEDIUM	THREADING
532	K-diff Pairs in an Array	3 .cpp
408	Valid Word Abbreviation	1 .cpp
2802	Find The K-th Lucky Number	3 .py	MEDIUM	MATH BINARY TREE RECURSION BINARY
1570	Dot Product of Two Sparse Vectors	1 .cpp
873	Length of Longest Fibonacci Subsequence	2 .cpp	MEDIUM	FIBONACCI DP LONGEST INCREASE SEQUENCE BRUTEFORCE
1017	Convert to Base -2	2 .cpp
1291	Sequential Digits	2 .cpp	MEDIUM	BFS DFS
875	Koko Eating Bananas	1 .py	MEDIUM	BINARY SEARCH
49	Group Anagrams	2 .py .cpp	MEDIUM	SORTING
125	Valid Palindrome	1 .cpp
566	Reshape the Matrix	4 .cpp
1539	Kth Missing Positive Number	1 .cpp	EASY	HASH MAP
1926	Nearest Exit from Entrance in Maze	1 .py	MEDIUM	BFS
1100	Find K-Length Substrings With No Repeated Characters	2 .cpp
1415	The k-th Lexicographical String of All Happy Strings of Length n	1 .cpp	MEDIUM	RECURSION DFS
1991	Find the Middle Index in Array	1 .py	EASY	PREFIX SUM
1458	Max Dot Product of Two Subsequences	1 .cpp	HARD	DP
83	Remove Duplicates from Sorted List	2 .py	EASY	TWO POINTER HASH MAP
1822	Sign of the Product of an Array	1 .go	EASY	MATH
2744	Find Maximum Number of String Pairs	1 .py	EASY	STRING HASH MAP
1624	Largest Substring Between Two Equal Characters	2 .py .cpp	EASY	HASH MAP
74	Search a 2D Matrix	3 .cpp
1413	Minimum Value to Get Positive Step by Step Sum	1 .cpp	EASY	PREFIX SUM
501	Find Mode in Binary Search Tree	3 .cpp
297	Serialize and Deserialize Binary Tree	1 .cpp
2255	Count Prefixes of a Given String	1 .py	EASY	TRIE
2609	Find the Longest Balanced Substring of a Binary String	1 .py	EASY	MATH STRING
876	Middle of the Linked List	2 .cpp
2264	Largest 3-Same-Digit Number in String	1 .py	EASY	MATH BRUTEFORCE
374	Guess Number Higher or Lower	2 .cpp
1876	Substrings of Size Three with Distinct Characters	1 .py	EASY	STRING
1133	Largest Unique Number	5 .py .cpp .js
1282	Group the People Given the Group Size They Belong To	1 .cpp	MEDIUM	GREEDY HASH MAP
16	3Sum Closest	1 .cpp
1605	Find Valid Matrix Given Row and Column Sums	1 .cpp	MEDIUM	GREEDY
1269	Number of Ways to Stay in the Same Place After Some Steps	1 .py	HARD	RECURSION DP
15	3Sum	2 .cpp
1392	Longest Happy Prefix	1 .py
2022	Convert 1D Array Into 2D Array	1 .py	EASY	ARRAY
1120	Maximum Average Subtree	2 .py .cpp	MEDIUM	DFS
2553	Separate the Digits in an Array	1 .py	EASY	MATH
442	Find All Duplicates in an Array	1 .py	MEDIUM
228	Summary Ranges	1 .cpp	MEDIUM	TWO POINTER
261	Graph Valid Tree	2 .cpp
965	Univalued Binary Tree	2 .cpp
492	Construct the Rectangle	3 .java
999	Available Captures for Rook	1 .cpp
1267	Count Servers that Communicate	1 .py	MEDIUM	HASH MAP
1002	Find Common Characters	2 .cpp .java	EASY	STRING ARRAY
520	Detect Capital	1 .js	EASY	REGEXP STRING
633	Sum of Square Numbers	2 .cpp
1222	Queens That Can Attack the King	1 .cpp	MEDIUM	ARRAY HASH MAP
322	Coin Change	2 .cpp
819	Most Common Word	2 .cpp
2582	Pass the Pillow	1 .py	EASY	MATH
133	Clone Graph	2 .cpp .java
1725	Number Of Rectangles That Can Form The Largest Square	1 .py	EASY	MATH
525	Contiguous Array	1 .cpp	MEDIUM	PREFIX SUM ARRAY HASH MAP
237	Delete Node in a Linked List	1 .py	EASY	LINKED LIST
690	Employee Importance	4 .cpp .java
3074	Apple Redistribution into Boxes	2 .py	EASY	GREEDY BINARY SEARCH
395	Longest Substring with At Least K Repeating Characters	1 .cpp	MEDIUM	DIVIDE-AND-CONQUER
1328	Break a Palindrome	1 .js	MEDIUM
867	Transpose Matrix	1 .cpp
988	Smallest String Starting From Leaf	1 .cpp	MEDIUM	DFS
1265	Print Immutable Linked List in Reverse	2 .cpp	MEDIUM	RECURSION LINKED LIST STACK
1952	Three Divisors	1 .py	EASY	MATH
1400	Construct K Palindrome Strings	1 .cpp	MEDIUM	PALINDROME BITSET
1925	Count Square Sum Triples	1 .py	EASY	MATH
946	Validate Stack Sequences	1 .cpp	MEDIUM	GREEDY STACK
2847	Smallest Number With Given Digit Product	1 .py	MEDIUM	MATH GREEDY
39	Combination Sum	1 .cpp
1288	Remove Covered Intervals	1 .cpp	MEDIUM	LINE SWEEP SORTING
6	ZigZag Conversion	1 .cpp	MEDIUM	STRING SIMULATION
991	Broken Calculator	1 .cpp
944	Delete Columns to Make Sorted	1 .cpp
931	Minimum Falling Path Sum	1 .cpp
1221	Split a String in Balanced Strings	1 .cpp
146	LRU Cache	1 .cpp	MEDIUM	LINKED LIST LRU
2980	Check if Bitwise OR Has Trailing Zeros	1 .py	EASY	MATH
779	K-th Symbol in Grammar	1 .py	MEDIUM	RECURSION
1060	Missing Element in Sorted Array	2 .cpp
1220	Count Vowels Permutation	1 .cpp	HARD	DP
1154	Day of the Year	1 .cpp	EASY	MATH DATE
3046	Split the Array	1 .py	EASY	HASH MAP
915	Partition Array into Disjoint Intervals	1 .cpp
24	Swap Nodes in Pairs	1 .cpp	MEDIUM	RECURSION
51	N-Queens	1 .cpp	HARD	RECURSION DFS BACKTRACKING
2706	Buy Two Chocolates	1 .py	EASY	SEARCH
59	Spiral Matrix II	1 .java	MEDIUM	SIMULATION
353	Design Snake Game	1 .cpp
2335	Minimum Amount of Time to Fill Cups	1 .py	EASY	MATH
2229	Check if an Array Is Consecutive	1 .py	EASY	SORTING
1880	Check if Word Equals Summation of Two Words	1 .py	EASY	MATH
1513	Number of Substrings With Only 1s	1 .py	MEDIUM	MATH
1387	Sort Integers by The Power Value	1 .cpp	MEDIUM	RECURSION DP
250	Count Univalue Subtrees	5 .cpp .java
884	Uncommon Words from Two Sentences	2 .java
1399	Count Largest Group	1 .cpp	EASY
892	Surface Area of 3D Shapes	3 .py .cpp	EASY	MATH COUNTING GEOMETRY
1047	Remove All Adjacent Duplicates In String	4 .py .cpp
205	Isomorphic Strings	1 .cpp
969	Pancake Sorting	1 .cpp	MEDIUM	ARRAY
2894	Divisible and Non-divisible Sums Difference	1 .py	EASY	MATH
1261	Find Elements in a Contaminated Binary Tree	1 .cpp	MEDIUM	DFS
2165	Smallest Value of the Rearranged Number	1 .py	MEDIUM	SORTING
3174	Clear Digits	1 .py	EASY	STACK
437	Path Sum III	1 .cpp
1273	Delete Tree Nodes	1 .cpp
1272	Remove Interval	1 .cpp	MEDIUM	INTERVAL
347	Top K Frequent Elements	2 .cpp
389	Find the Difference	1 .py	EASY	XOR
2864	Maximum Odd Binary Number	1 .py	EASY	MATH BINARY
207	Course Schedule	1 .py	MEDIUM	TOPOLOGICAL SORT GRAPH
3232	Find if Digit Game Can Be Won	1 .py	EASY	MATH GAME
1228	Missing Number In Arithmetic Progression	1 .cpp
766	Toeplitz Matrix	2 .cpp
724	Find Pivot Index	2 .cpp
942	DI String Match	2 .cpp .java
47	Permutations II	1 .cpp	MEDIUM	PERMUTATION DFS HASH MAP
1026	Maximum Difference Between Node and Ancestor	1 .cpp
1437	Check If All 1's Are at Least Length K Places Away	1 .cpp	MEDIUM	ARRAY
290	Word Pattern	1 .cpp	EASY	HASH MAP
129	Sum Root to Leaf Numbers	1 .py	MEDIUM	BFS
1020	Partition Array Into Three Parts With Equal Sum	1 .cpp
2011	Final Value of Variable After Performing Operations	1 .py	EASY	LAMBDA
1436	Destination City	1 .cpp	EASY	TREE
2248	Intersection of Multiple Arrays	1 .py	EASY	HASH MAP
1171	Remove Zero Sum Consecutive Nodes from Linked List	1 .cpp	MEDIUM	PREFIX SUM LINKED LIST
653	Two Sum IV Input is a BST	6 .cpp .java
1185	Day of the Week	1 .cpp
190	Reverse Bits	1 .py	EASY	MATH
744	Find Smallest Letter Greater Than Target	4 .js .cpp
976	Largest Perimeter Triangle	3 .py .cpp .java	EASY	TRIANGLE GREEDY ARRAY SORTING
348	Design Tic-Tac-Toe	1 .cpp
1281	Subtract the Product and Sum of Digits of an Integer	1 .cpp	EASY	MATH
346	Moving Average from Data Stream	1 .cpp	EASY	DEQUE
2753	Count Houses in a Circular Street II	1 .py	HARD	DESIGN
334	Increasing Triplet Subsequence	2 .py .cpp	MEDIUM	MATH
1897	Redistribute Characters to Make All Strings Equal	2 .py .go	EASY	STRING HASH MAP
2600	K Items With the Maximum Sum	1 .py	EASY	MATH
917	Reverse Only Letters	3 .cpp .java
701	Insert into a Binary Search Tree	2 .cpp	MEDIUM	RECURSION TREE
516	Longest Palindromic Subsequence	1 .py	MEDIUM	DP
1161	Maximum Level Sum of a Binary Tree	1 .cpp
2510	Check if There is a Path With Equal Number of 0's And 1's	1 .py	MEDIUM	DP
746	Min Cost Climbing Stairs	2 .cpp
2710	Remove Trailing Zeros From a String	1 .py	EASY	STRING
1971	Find if Path Exists in Graph	1 .py	EASY	BFS GRAPH
367	Valid Perfect Square	4 .cpp
2032	Two Out of Three	1 .py	EASY	HASH MAP
693	Binary Number with Alternating Bits	2 .cpp
1984	Minimum Difference Between Highest and Lowest of K Scores	1 .py	EASY	SORTING
2437	Number of Valid Clock Times	1 .py	EASY	MATH
445	Add Two Numbers II	1 .cpp	MEDIUM	LINKED LIST STACK
684	Redundant Connection	1 .cpp	MEDIUM	UNION FIND
2544	Alternating Digit Sum	1 .py	EASY	MATH
247	Strobogrammatic Number II	1 .cpp	MEDIUM	RECURSION
300	Longest Increasing Subsequence	1 .cpp
12	Integer to Roman	1 .py	MEDIUM	MATH STRING
951	Flip Equivalent Binary Trees	2 .cpp
50	Pow(x, n)	1 .cpp	MEDIUM	RECURSION
1094	Car Pooling	2 .cpp	MEDIUM	GREEDY HASH MAP
201	Bitwise AND of Numbers Range	1 .cpp	MEDIUM	BIT
859	Buddy Strings	1 .cpp
1005	Maximize Sum Of Array After K Negations	2 .cpp	EASY	PRIORITY QUEUE ARRAY
2177	Find Three Consecutive Integers That Sum to a Given Number	1 .py	MEDIUM	MATH
401	Binary Watch	1 .cpp
933	Number of Recent Calls	2 .cpp .java
1346	Check If N and Its Double Exist	1 .go	EASY	HASH MAP
2139	Minimum Moves to Reach Target Score	1 .py	MEDIUM	GREEDY
841	Keys and Rooms	1 .cpp
937	Reorder Data in Log Files	1 .cpp	EASY	SORTING
2915	Length of the Longest Subsequence That Sums to Target	1 .py	MEDIUM	DP KNAPSACK
609	Find Duplicate File in System	1 .js	MEDIUM	HASH MAP
1244	Design A Leaderboard	1 .cpp	MEDIUM	MULTI SET HASH MAP
958	Check Completeness of a Binary Tree	2 .cpp .java
2099	Find Subsequence of Length K With the Largest Sum	1 .py	EASY	SLIDING WINDOW
1208	Get Equal Substrings Within Budget	1 .cpp
1920	Build Array from Permutation	1 .py	EASY	ARRAY
256	Paint House	1 .cpp
704	Binary Search	1 .java
217	Contains Duplicate	1 .js	EASY	HASH MAP
1071	Greatest Common Divisor of Strings	1 .cpp
1485	Clone Binary Tree With Random Pointer	1 .cpp	MEDIUM	RECURSION HASH MAP
18	4Sum	1 .cpp
1490	Clone N-ary Tree	1 .cpp	MEDIUM	RECURSION DFS HASH MAP
150	Evaluate Reverse Polish Notation	1 .py	MEDIUM	STACK
1837	Sum of Digits in Base K	1 .py	EASY	MATH
634	Find the Derangement of An Array	1 .py	MEDIUM	MATH DP
2696	Minimum String Length After Removing Substrings	1 .py	EASY	STACK
1137	N-th Tribonacci Number	2 .cpp
953	Verifying an Alien Dictionary	1 .cpp
3101	Count Alternating Subarrays	1 .py	MEDIUM	DP
23	Merge k Sorted Lists	1 .cpp	HARD	RECURSION DIVIDE-AND-CONQUER
760	Find Anagram Mappings	3 .cpp .java
2924	Find Champion II	1 .py	MEDIUM	GRAPH
1165	Single-Row Keyboard	2 .cpp	EASY	STRING HASH MAP
52	N-Queens II	1 .cpp	HARD	RECURSION DFS BACKTRACKING
2265	Count Nodes Equal to Average of Subtree	1 .py	MEDIUM	DFS
1135	Connecting Cities With Minimum Cost	2 .cpp
743	Network Delay Time	1 .py	MEDIUM	GRAPH
669	Trim a Binary Search Tree	1 .cpp
415	Add Strings	2 .py .cpp	EASY	MATH
1874	Minimize Product Sum of Two Arrays	1 .go	MEDIUM	GREEDY
921	Minimum Add to Make Parentheses Valid	1 .cpp
2485	Find the Pivot Integer	1 .py	EASY	MATH
836	Rectangle Overlap	1 .cpp	EASY	GEOMETRY
246	Strobogrammatic Number	2 .cpp
2101	Detonate the Maximum Bombs	1 .py	MEDIUM	DFS
703	Kth Largest Element in a Stream	1 .cpp
5453	Running Sum of 1d Array	1 .cpp	EASY	PREFIX SUM
1396	Design Underground System	1 .cpp	MEDIUM	HASH MAP
650	2 Keys Keyboard	1 .py	MEDIUM	DP
2717	Semi-Ordered Permutation	1 .py	EASY	MATH
251	Flatten 2D Vector	2 .cpp
643	Maximum Average Subarray I	4 .js .cpp .java
1184	Distance Between Bus Stops	1 .py	EASY	MATH GRAPH
541	Reverse String II	1 .cpp
1518	Water Bottles	1 .java	EASY	SIMULATION
1522	Diameter of N-Ary Tree	1 .cpp	MEDIUM	DFS
945	Minimum Increment to Make Array Unique	1 .py	MEDIUM	GREEDY SORTING
105	Construct Binary Tree from Preorder and Inorder Traversal	1 .cpp
2529	Maximum Count of Positive Integer and Negative Integer	1 .py	EASY	BINARY SEARCH
2368	Reachable Nodes With Restrictions	1 .py	MEDIUM	DFS GRAPH
897	Increasing Order Search Tree	4 .py .cpp	EASY	RECURSION
1598	Crawler Log Folder	1 .cpp	EASY	SIMULATION
997	Find the Town Judge	1 .java
101	Symmetric Tree	1 .py	EASY	RECURSION DFS
103	Binary Tree Zigzag Level Order Traversal	3 .py .cpp	MEDIUM	BFS
82	Remove Duplicates from Sorted List II	1 .cpp	MEDIUM	LINKED LIST
1232	Check If It Is a Straight Line	1 .cpp	EASY	GEOMETRY
1249	Minimum Remove to Make Valid Parentheses	1 .cpp	MEDIUM	GREEDY PARENTHESES
949	Largest Time for Given Digits	1 .cpp	EASY	PERMUTATION
589	N-ary Tree Preorder Traversal	1 .py	EASY	STACK
799	Champagne Tower	1 .py	MEDIUM	DP
1422	Maximum Score After Splitting a String	1 .cpp	EASY	PREFIX SUM
1197	Minimum Knight Moves	1 .py	MEDIUM	DP
812	Largest Triangle Area	1 .cpp
830	Positions of Large Groups	2 .cpp .java
1576	Replace All ?'s to Avoid Consecutive Repeating Characters	1 .cpp	EASY	STRING
985	Sum of Even Numbers After Queries	2 .js .java
28	Implement strStr()	1 .cpp
2443	Sum of Number and Its Reverse	1 .py	MEDIUM	BRUTEFORCE
1382	Balance a Binary Search Tree	2 .py .cpp	MEDIUM	RECURSION BINARY TREE
242	Valid Anagram	1 .cpp	EASY	STRING HASH MAP
1796	Second Largest Digit in a String	1 .cpp	EASY	STRING HASH MAP
967	Numbers With Same Consecutive Differences	1 .py	MEDIUM	DFS
2769	Find the Maximum Achievable Number	1 .py	EASY	MATH GREEDY
433	Minimum Genetic Mutation	1 .py	MEDIUM	BFS
804	Unique Morse Code Words	2 .cpp .java
166	Fraction to Recurring Decimal	1 .java	MEDIUM	MATH HASH MAP
91	Decode Ways	1 .cpp
2639	Find the Width of Columns of a Grid	1 .py	EASY	MATH MATRIX
170	Two Sum III - Data structure design	3 .cpp	EASY	DESIGN
264	Ugly Number II	1 .py	MEDIUM	MATH HEAP
700	Search in a Binary Search Tree	6 .cpp .js .java
686	Repeated String Match	2 .js
2697	Lexicographically Smallest Palindrome	1 .py	EASY	TWO POINTER
645	Set Mismatch	3 .cpp
1119	Remove Vowels from a String	1 .cpp
1237	Find Positive Integer Solution for a Given Equation	2 .cpp	EASY	TWO POINTER BINARY SEARCH

Database

ID	Blog	Solutions	Diffculty	Tags
608	Tree Node	4 .sql	MEDIUM	SQL
3054	Binary Tree Nodes	1 .sql	MEDIUM	SQL
612	Shortest Distance in a Plane	4 .sql	MEDIUM	SQL
176	Second Highest Salary	1 .sql	EASY	MATH SQL
577	Employee Bonus	1 .sql	EASY	SQL
570	Managers with at Least 5 Direct Reports	2 .sql	MEDIUM	SQL
584	Find Customer Referee	1 .sql	EASY	SQL
627	Swap Salary	2 .sql	EASY	SQL
619	Biggest Single Number	1 .sql	EASY	SQL

Total 585 Questions: 9 Database, 576 Algorithms

By Difficulty

• MEDIUM
• EASY
• HARD

By Programming Language

• .py
• .cpp
• .rs
• .java
• .js
• .php
• .go
• .sql
• .c

By Tag

• MATH
• ARRAY
• DATE
• DFS
• STRING
• DP
• GREEDY
• SQRT DECOMPOSITION
• TWO POINTER
• HASH MAP
• RECURSION
• BINARY TREE
• LINE SWEEP
• BFS
• PRIORITY QUEUE
• BRUTEFORCE
• GAME
• SLIDING WINDOW
• MEMOIZATION
• SET
• DEQUE
• DIVIDE-AND-CONQUER
• SORTING
• QUEUE
• GRAPH
• TREE
• BINARY SEARCH
• MATRIX
• LINKED LIST
• SQL
• PARTITION
• BINARY NUMBER
• GRID
• SIMULATION
• DESIGN
• BITMASK
• HEAP
• PREFIX SUM
• GCD
• BACKTRACKING
• BINARY
• STACK
• GROUPBY
• DECISION TREE
• GEOMETRY
• PERMUTATION
• RANDOM
• BIT HACKS
• THREADING
• FIBONACCI
• LONGEST INCREASE SEQUENCE
• TRIE
• REGEXP
• PALINDROME
• BITSET
• LRU
• SEARCH
• COUNTING
• INTERVAL
• XOR
• TOPOLOGICAL SORT
• LAMBDA
• TRIANGLE
• UNION FIND
• BIT
• KNAPSACK
• MULTI SET
• PARENTHESES

Index generated by script at 23/10/2024 21:54:07