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DifficultyTopic102 of 102
No.ProblemDifficultyFrequency
2050Parallel Courses IIIHard
100.0%
202Happy Number
Math
Easy
100.0%
210Course Schedule IIMedium
100.0%
588Design In-Memory File SystemHard
87.5%
212Word Search IIHard
87.5%
2742Painting the WallsHard
87.5%
2303Calculate Amount Paid in TaxesEasy
87.5%
42Trapping Rain WaterHard
87.5%
76Minimum Window Substring
StringTreeSliding Window
Hard
87.5%
1600Throne InheritanceMedium
87.5%
2096Step-By-Step Directions From a Binary Tree Node to Another
TreeLinked List
Medium
87.5%
2856Minimum Array Length After Pair Removals
Array
Medium
75.0%
1639Number of Ways to Form a Target String Given a Dictionary
StringMath
Hard
75.0%
1235Maximum Profit in Job SchedulingHard
75.0%
3177Find the Maximum Length of a Good Subsequence II
String
Hard
75.0%
3176Find the Maximum Length of a Good Subsequence I
String
Medium
75.0%
3155Maximum Number of Upgradable Servers
Math
Medium
75.0%
438Find All Anagrams in a String
String
Medium
75.0%
2851String Transformation
String
Hard
75.0%
2062Count Vowel Substrings of a String
StringTree
Easy
75.0%
23Merge k Sorted ListsHard
75.0%
21Merge Two Sorted ListsEasy
62.5%
981Time Based Key-Value StoreMedium
62.5%
545Boundary of Binary Tree
Tree
Medium
62.5%
146LRU CacheMedium
62.5%
224Basic CalculatorHard
62.5%
362Design Hit CounterMedium
62.5%
706Design HashMapEasy
62.5%
207Course ScheduleMedium
62.5%
155Min Stack
Stack/Queue
Medium
62.5%
621Task SchedulerMedium
62.5%
138Copy List with Random PointerMedium
62.5%
849Maximize Distance to Closest PersonMedium
62.5%
695Max Area of Island
Graph
Medium
62.5%
1Two Sum
Sliding Window
Easy
62.5%
1353Maximum Number of Events That Can Be Attended
Math
Medium
62.5%
211Design Add and Search Words Data StructureMedium
62.5%
1233Remove Sub-Folders from the FilesystemMedium
62.5%
71Simplify PathMedium
62.5%
347Top K Frequent Elements
Heap
Medium
62.5%
1136Parallel CoursesMedium
62.5%
1242Web Crawler MultithreadedMedium
62.5%
1236Web CrawlerMedium
62.5%
243Shortest Word DistanceEasy
62.5%
3880Minimum Absolute Difference Between Two ValuesEasy
62.5%
10Regular Expression MatchingHard
50.0%
116Populating Next Right Pointers in Each Node
Linked List
Medium
50.0%
273Integer to English Words
Math
Hard
50.0%
787Cheapest Flights Within K Stops
Heap
Medium
50.0%
380Insert Delete GetRandom O(1)Medium
50.0%
872Leaf-Similar Trees
Tree
Easy
50.0%
528Random Pick with WeightMedium
50.0%
1146Snapshot Array
Array
Medium
50.0%
687Longest Univalue PathMedium
50.0%
540Single Element in a Sorted Array
Array
Medium
50.0%
13Roman to Integer
Math
Easy
50.0%
827Making A Large Island
Graph
Hard
50.0%
917Reverse Only LettersEasy
50.0%
947Most Stones Removed with Same Row or ColumnMedium
50.0%
841Keys and RoomsMedium
50.0%
1751Maximum Number of Events That Can Be Attended II
Math
Hard
50.0%
635Design Log Storage SystemMedium
50.0%
1166Design File SystemMedium
50.0%
994Rotting OrangesMedium
50.0%
1494Parallel Courses IIHard
50.0%
1057Campus BikesMedium
50.0%
261Graph Valid Tree
TreeGraph
Medium
50.0%
641Design Circular DequeMedium
50.0%
3092Most Frequent IDsMedium
50.0%
117Populating Next Right Pointers in Each Node II
Linked List
Medium
37.5%
227Basic Calculator IIMedium
37.5%
253Meeting Rooms IIMedium
37.5%
271Encode and Decode Strings
String
Medium
37.5%
1898Maximum Number of Removable Characters
Math
Medium
37.5%
2265Count Nodes Equal to Average of Subtree
TreeLinked List
Medium
37.5%
11Container With Most WaterMedium
37.5%
295Find Median from Data Stream
Heap
Hard
37.5%
105Construct Binary Tree from Preorder and Inorder Traversal
Tree
Medium
37.5%
2467Most Profitable Path in a Tree
Tree
Medium
37.5%
52N-Queens IIHard
37.5%
408Valid Word AbbreviationEasy
37.5%
208Implement Trie (Prefix Tree)
Tree
Medium
37.5%
286Walls and GatesMedium
37.5%
1631Path With Minimum EffortMedium
37.5%
402Remove K Digits
Math
Medium
37.5%
121Best Time to Buy and Sell StockEasy
37.5%
435Non-overlapping IntervalsMedium
37.5%
881Boats to Save PeopleMedium
37.5%
79Word SearchMedium
37.5%
729My Calendar IMedium
37.5%
1604Alert Using Same Key-Card Three or More Times in a One Hour PeriodMedium
37.5%
622Design Circular Queue
Stack/Queue
Medium
37.5%
276Paint FenceMedium
37.5%
2Add Two Numbers
Math
Medium
37.5%
45Jump Game IIMedium
37.5%
490The MazeMedium
37.5%
2458Height of Binary Tree After Subtree Removal Queries
Tree
Hard
37.5%
1472Design Browser HistoryMedium
37.5%
200Number of Islands
GraphMath
Medium
37.5%
886Possible Bipartition
DP
Medium
37.5%
934Shortest BridgeMedium
37.5%
427Construct Quad Tree
Tree
Medium
37.5%