Uber LeetCode Questions

362 questions all-time · 45 easy · 215 medium · 102 hard

#	Problem	Difficulty	Frequency	Acceptance
1	Bus Routes Array, Hash Table, Breadth-First Search	Hard	100	0.5%
2	Alien Dictionary Array, String, Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort	Hard	94	0.4%
3	Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit Array, Queue, Sliding Window, Heap (Priority Queue), Ordered Set, Monotonic Queue	Medium	94	0.6%
4	Number of Islands Array, Depth-First Search, Breadth-First Search, Union-Find, Matrix	Medium	90	0.6%
5	Number of Islands II Array, Hash Table, Union-Find	Hard	88	0.4%
6	Squares of a Sorted Array Array, Two Pointers, Sorting	Easy	86	0.7%
7	Construct Quad Tree Array, Divide and Conquer, Tree, Matrix	Medium	85	0.8%
8	Kth Smallest Element in a BST Tree, Depth-First Search, Binary Search Tree, Binary Tree	Medium	82	0.8%
9	First Unique Number Array, Hash Table, Design, Queue, Data Stream	Medium	81	0.6%
10	Find the Closest Palindrome Math, String	Hard	81	0.3%
11	Word Search Array, String, Backtracking, Depth-First Search, Matrix	Medium	77	0.5%
12	LRU Cache Hash Table, Linked List, Design, Doubly-Linked List	Medium	77	0.5%
13	Insert Delete GetRandom O(1) Array, Hash Table, Math, Design, Randomized	Medium	77	0.6%
14	Design Hit Counter Array, Binary Search, Design, Queue, Data Stream	Medium	76	0.7%
15	Word Search II Array, String, Backtracking, Trie, Matrix	Hard	74	0.4%
16	Minimum Edge Reversals So Every Node Is Reachable Dynamic Programming, Depth-First Search, Breadth-First Search, Graph Theory	Hard	74	0.6%
17	Best Time to Buy and Sell Stock Array, Dynamic Programming	Easy	72	0.6%
18	My Calendar I Array, Binary Search, Design, Segment Tree, Ordered Set	Medium	71	0.6%
19	Product of Array Except Self Array, Prefix Sum	Medium	70	0.7%
20	Evaluate Division Array, String, Depth-First Search, Breadth-First Search, Union-Find, Graph Theory, Shortest Path	Medium	70	0.6%
21	Random Pick with Weight Array, Math, Binary Search, Prefix Sum, Randomized	Medium	70	0.5%
22	Count Paths That Can Form a Palindrome in a Tree Hash Table, Bit Manipulation, Tree, Depth-First Search	Hard	70	0.5%
23	Text Justification Array, String, Simulation	Hard	69	0.5%
24	Leftmost Column with at Least a One Array, Binary Search, Matrix, Interactive	Medium	69	0.6%
25	Block Placement Queries Array, Binary Search, Binary Indexed Tree, Segment Tree, Ordered Set	Hard	68	0.4%
26	Course Schedule II Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort	Medium	66	0.6%
27	Valid Sudoku Array, Hash Table, Matrix	Medium	65	0.6%
28	Spiral Matrix Array, Matrix, Simulation	Medium	65	0.6%
29	Making A Large Island Array, Depth-First Search, Breadth-First Search, Union-Find, Matrix	Hard	65	0.6%
30	Course Schedule Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort	Medium	64	0.5%
31	Find Minimum Time to Reach Last Room I Array, Graph Theory, Heap (Priority Queue), Matrix, Shortest Path	Medium	64	0.6%
32	Letter Combinations of a Phone Number Hash Table, String, Backtracking	Medium	63	0.7%
33	Group Anagrams Array, Hash Table, String, Sorting	Medium	63	0.7%
34	Basic Calculator Math, String, Stack, Recursion	Hard	63	0.5%
35	Top K Frequent Words Array, Hash Table, String, Trie, Sorting, Heap (Priority Queue), Bucket Sort, Counting	Medium	63	0.6%
36	Shortest Bridge Array, Depth-First Search, Breadth-First Search, Matrix	Medium	63	0.6%
37	Word Break Array, Hash Table, String, Dynamic Programming, Trie, Memoization	Medium	62	0.5%
38	Meeting Rooms II Array, Two Pointers, Greedy, Sorting, Heap (Priority Queue), Prefix Sum	Medium	62	0.5%
39	Design In-Memory File System Hash Table, String, Design, Trie, Sorting	Hard	62	0.5%
40	Final Prices With a Special Discount in a Shop Array, Stack, Monotonic Stack	Easy	62	0.8%
41	Shuffle an Array Array, Math, Design, Randomized	Medium	60	0.6%
42	The Earliest Moment When Everyone Become Friends Array, Union-Find, Sorting	Medium	60	0.7%
43	Two Sum Array, Hash Table	Easy	59	0.6%
44	Serialize and Deserialize Binary Tree String, Tree, Depth-First Search, Breadth-First Search, Design, Binary Tree	Hard	59	0.6%
45	Escape the Spreading Fire Array, Binary Search, Breadth-First Search, Matrix	Hard	59	0.4%
46	Split Message Based on Limit String, Enumeration	Hard	59	0.4%
47	Rotating the Box Array, Two Pointers, Matrix	Medium	59	0.8%
48	Merge k Sorted Lists Linked List, Divide and Conquer, Heap (Priority Queue), Merge Sort	Hard	58	0.6%
49	Search in Rotated Sorted Array Array, Binary Search	Medium	58	0.5%
50	Minimum Window Substring Hash Table, String, Sliding Window	Hard	58	0.5%
51	Valid Anagram Hash Table, String, Sorting	Easy	58	0.7%
52	Top K Frequent Elements Array, Hash Table, Divide and Conquer, Sorting, Heap (Priority Queue), Bucket Sort, Counting, Quickselect	Medium	58	0.7%
53	Cherry Pickup Array, Dynamic Programming, Matrix	Hard	58	0.4%
54	Minimum Number of Operations to Make Array Continuous Array, Hash Table, Binary Search, Sliding Window	Hard	58	0.5%
55	Roman to Integer Hash Table, Math, String	Easy	56	0.7%
56	All O`one Data Structure Hash Table, Linked List, Design, Doubly-Linked List	Hard	56	0.4%
57	The Maze Array, Depth-First Search, Breadth-First Search, Matrix	Medium	56	0.6%
58	Minimum Time to Complete Trips Array, Binary Search	Medium	56	0.4%
59	Divide Nodes Into the Maximum Number of Groups Depth-First Search, Breadth-First Search, Union-Find, Graph Theory	Hard	56	0.7%
60	Sudoku Solver Array, Hash Table, Backtracking, Matrix	Hard	54	0.7%
61	Decode Ways String, Dynamic Programming	Medium	54	0.4%
62	House Robber III Dynamic Programming, Tree, Depth-First Search, Binary Tree	Medium	54	0.6%
63	Delete Node in a BST Tree, Binary Search Tree, Binary Tree	Medium	54	0.5%
64	Exclusive Time of Functions Array, Stack	Medium	54	0.7%
65	Replace Words Array, Hash Table, String, Trie	Medium	54	0.7%
66	Asteroid Collision Array, Stack, Simulation	Medium	54	0.5%
67	Koko Eating Bananas Array, Binary Search	Medium	54	0.5%
68	Time Based Key-Value Store Hash Table, String, Binary Search, Design	Medium	54	0.5%
69	Minimum Operations to Reduce an Integer to 0 Dynamic Programming, Greedy, Bit Manipulation	Medium	54	0.6%
70	String to Integer (atoi) String	Medium	53	0.2%
71	Regular Expression Matching String, Dynamic Programming, Recursion	Hard	53	0.3%
72	Combination Sum Array, Backtracking	Medium	53	0.8%
73	Subsets Array, Backtracking, Bit Manipulation	Medium	53	0.8%
74	Valid Palindrome Two Pointers, String	Easy	53	0.5%
75	Min Stack Stack, Design	Medium	53	0.6%
76	Find Peak Element Array, Binary Search	Medium	53	0.5%
77	Excel Sheet Column Number Math, String	Easy	53	0.7%
78	Trips and Users Database	Hard	53	0.4%
79	Coin Change Array, Dynamic Programming, Breadth-First Search	Medium	53	0.5%
80	Find K Pairs with Smallest Sums Array, Heap (Priority Queue)	Medium	53	0.4%
81	Split Array Largest Sum Array, Binary Search, Dynamic Programming, Greedy, Prefix Sum	Hard	53	0.6%
82	Encode and Decode TinyURL Hash Table, String, Design, Hash Function	Medium	53	0.9%
83	Regions Cut By Slashes Array, Hash Table, Depth-First Search, Breadth-First Search, Union-Find, Matrix	Medium	53	0.8%
84	Rotting Oranges Array, Breadth-First Search, Matrix	Medium	53	0.6%
85	Merge Strings Alternately Two Pointers, String	Easy	53	0.8%
86	Maximum Subarray Min-Product Array, Stack, Monotonic Stack, Prefix Sum	Medium	53	0.4%
87	Meeting Rooms III Array, Hash Table, Sorting, Heap (Priority Queue), Simulation	Hard	53	0.5%
88	Check if a String Is an Acronym of Words Array, String	Easy	53	0.8%
89	Points That Intersect With Cars Array, Hash Table, Prefix Sum	Easy	53	0.7%
90	Minimum Operations to Write the Letter Y on a Grid Array, Hash Table, Matrix, Counting	Medium	53	0.6%
91	Maximize Amount After Two Days of Conversions Array, String, Depth-First Search, Breadth-First Search, Graph Theory	Medium	53	0.6%
92	Maximum Coin Collection Array, Dynamic Programming	Medium	53	0.5%
93	The Maze II Array, Depth-First Search, Breadth-First Search, Graph Theory, Heap (Priority Queue), Matrix, Shortest Path	Medium	53	0.6%
94	Generate Parentheses String, Dynamic Programming, Backtracking	Medium	51	0.8%
95	Swap Nodes in Pairs Linked List, Recursion	Medium	51	0.7%
96	Maximum Depth of Binary Tree Tree, Depth-First Search, Breadth-First Search, Binary Tree	Easy	51	0.8%
97	Clone Graph Hash Table, Depth-First Search, Breadth-First Search, Graph Theory	Medium	51	0.7%
98	Copy List with Random Pointer Hash Table, Linked List	Medium	51	0.6%
99	Word Break II Array, Hash Table, String, Dynamic Programming, Backtracking, Trie, Memoization	Hard	51	0.6%
100	One Edit Distance Two Pointers, String	Medium	51	0.3%
101	Reverse Words in a String II Two Pointers, String	Medium	51	0.6%
102	Happy Number Hash Table, Math, Two Pointers	Easy	51	0.6%
103	Reverse Linked List Linked List, Recursion	Easy	51	0.8%
104	Implement Trie (Prefix Tree) Hash Table, String, Design, Trie	Medium	51	0.7%
105	Group Shifted Strings Array, Hash Table, String	Medium	51	0.7%
106	Factor Combinations Backtracking	Medium	51	0.5%
107	Palindrome Permutation Hash Table, String, Bit Manipulation	Easy	51	0.7%
108	Word Pattern Hash Table, String	Easy	51	0.4%
109	Word Pattern II Hash Table, String, Backtracking	Medium	51	0.5%
110	Optimal Account Balancing Array, Dynamic Programming, Backtracking, Bit Manipulation, Bitmask	Hard	51	0.5%
111	Longest Palindromic Subsequence String, Dynamic Programming	Medium	51	0.7%
112	Employee Importance Array, Hash Table, Tree, Depth-First Search, Breadth-First Search	Medium	51	0.7%
113	Falling Squares Array, Segment Tree, Ordered Set	Hard	51	0.5%
114	Flood Fill Array, Depth-First Search, Breadth-First Search, Matrix	Easy	51	0.7%
115	Random Pick with Blacklist Array, Hash Table, Math, Binary Search, Sorting, Randomized	Hard	51	0.4%
116	Fixed Point Array, Binary Search	Easy	51	0.6%
117	Parallel Courses Graph Theory, Topological Sort	Medium	51	0.6%
118	Minimum Score Triangulation of Polygon Array, Dynamic Programming	Medium	51	0.7%
119	Remove Zero Sum Consecutive Nodes from Linked List Hash Table, Linked List	Medium	51	0.5%
120	Find the City With the Smallest Number of Neighbors at a Threshold Distance Dynamic Programming, Graph Theory, Shortest Path	Medium	51	0.7%
121	Find the Distance Value Between Two Arrays Array, Two Pointers, Binary Search, Sorting	Easy	51	0.7%
122	Construct K Palindrome Strings Hash Table, String, Greedy, Counting	Medium	51	0.7%
123	Course Schedule IV Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort	Medium	51	0.6%
124	Number of Nodes in the Sub-Tree With the Same Label Hash Table, Tree, Depth-First Search, Breadth-First Search, Counting	Medium	51	0.6%
125	Remove Max Number of Edges to Keep Graph Fully Traversable Union-Find, Graph Theory	Hard	51	0.7%
126	Hopper Company Queries I Database	Hard	51	0.5%
127	Hopper Company Queries II Database	Hard	51	0.4%
128	Hopper Company Queries III Database	Hard	51	0.7%
129	Number Of Ways To Reconstruct A Tree Array, Hash Table, Tree, Graph Theory, Simulation	Hard	51	0.5%
130	Maximum Number of Eaten Apples Array, Greedy, Heap (Priority Queue)	Medium	51	0.4%
131	Maximum XOR for Each Query Array, Bit Manipulation, Prefix Sum	Medium	51	0.8%
132	Minimum Absolute Sum Difference Array, Binary Search, Sorting, Ordered Set	Medium	51	0.3%
133	Nearest Exit from Entrance in Maze Array, Breadth-First Search, Matrix	Medium	51	0.5%
134	Check for Contradictions in Equations Array, String, Depth-First Search, Union-Find, Graph Theory	Hard	51	0.4%
135	Array With Elements Not Equal to Average of Neighbors Array, Greedy, Sorting	Medium	51	0.5%
136	Check If String Is a Prefix of Array Array, Two Pointers, String	Easy	51	0.5%
137	Number of Strings That Appear as Substrings in Word Array, String	Easy	51	0.8%
138	Create Binary Tree From Descriptions Array, Hash Table, Tree, Binary Tree	Medium	51	0.8%
139	Intersection of Multiple Arrays Array, Hash Table, Sorting, Counting	Easy	51	0.7%
140	K Divisible Elements Subarrays Array, Hash Table, Trie, Rolling Hash, Hash Function, Enumeration	Medium	51	0.6%
141	Calculate Digit Sum of a String String, Simulation	Easy	51	0.7%
142	Minimum Sum of Squared Difference Array, Binary Search, Greedy, Sorting, Heap (Priority Queue)	Medium	51	0.3%
143	Number of People That Can Be Seen in a Grid Array, Stack, Matrix, Monotonic Stack	Medium	51	0.5%
144	Count Subarrays With Fixed Bounds Array, Queue, Sliding Window, Monotonic Queue	Hard	51	0.7%
145	Maximize Win From Two Segments Array, Binary Search, Sliding Window	Medium	51	0.4%
146	Number of Ways to Reach Destination in the Grid Math, Dynamic Programming, Combinatorics	Hard	51	0.6%
147	Find Pattern in Infinite Stream I Array, Sliding Window, Rolling Hash, String Matching, Interactive, Hash Function	Medium	51	0.6%
148	Find Pattern in Infinite Stream II Array, Sliding Window, Rolling Hash, String Matching, Interactive, Hash Function	Hard	51	0.7%
149	Maximum Increasing Triplet Value Array, Ordered Set	Medium	51	0.4%
150	Match Alphanumerical Pattern in Matrix I Array, Hash Table, String, Matrix	Medium	51	0.7%
151	Minimum Operations to Make Binary Array Elements Equal to One I Array, Bit Manipulation, Queue, Sliding Window, Prefix Sum	Medium	51	0.8%
152	Minimum Operations to Make Binary Array Elements Equal to One II Array, Dynamic Programming, Greedy	Medium	51	0.7%
153	Find the Number of Ways to Place People II Array, Math, Geometry, Sorting, Enumeration	Hard	51	0.6%
154	Find Minimum Time to Reach Last Room II Array, Graph Theory, Heap (Priority Queue), Matrix, Shortest Path	Medium	51	0.7%
155	Binary Tree Right Side View Tree, Depth-First Search, Breadth-First Search, Binary Tree	Medium	49	0.7%
156	Open the Lock Array, Hash Table, String, Breadth-First Search	Medium	49	0.6%
157	Number of Black Blocks Array, Hash Table, Enumeration	Medium	49	0.4%
158	Minimum Cost to Equalize Arrays Using Swaps Array, Hash Table, Greedy, Counting	Medium	49	0.5%
159	Merge Intervals Array, Sorting	Medium	46	0.5%
160	Largest Rectangle in Histogram Array, Stack, Monotonic Stack	Hard	46	0.5%
161	Word Ladder Hash Table, String, Breadth-First Search	Hard	46	0.5%
162	Sliding Window Maximum Array, Queue, Sliding Window, Heap (Priority Queue), Monotonic Queue	Hard	46	0.5%
163	Find Median from Data Stream Two Pointers, Design, Sorting, Heap (Priority Queue), Data Stream	Hard	46	0.5%
164	Best Time to Buy and Sell Stock using Strategy Array, Sliding Window, Prefix Sum	Medium	46	0.6%
165	Rotate Image Array, Math, Matrix	Medium	43	0.8%
166	Dungeon Game Array, Dynamic Programming, Matrix	Hard	43	0.4%
167	Find All Possible Recipes from Given Supplies Array, Hash Table, String, Graph Theory, Topological Sort	Medium	43	0.6%
168	Subarray Sums Divisible by K Array, Hash Table, Prefix Sum	Medium	43	0.6%
169	Boundary of Binary Tree Tree, Depth-First Search, Binary Tree	Medium	43	0.5%
170	Longest Path With Different Adjacent Characters Array, String, Tree, Depth-First Search, Graph Theory, Topological Sort	Hard	43	0.5%
171	Minimum Cost to Make at Least One Valid Path in a Grid Array, Breadth-First Search, Graph Theory, Heap (Priority Queue), Matrix, Shortest Path	Hard	43	0.7%
172	Trapping Rain Water Array, Two Pointers, Dynamic Programming, Stack, Monotonic Stack	Hard	40	0.7%
173	Insert Interval Array	Medium	40	0.5%
174	Longest Consecutive Sequence Array, Hash Table, Union-Find	Medium	40	0.5%
175	Candy Array, Greedy	Hard	40	0.5%
176	House Robber Array, Dynamic Programming	Medium	40	0.5%
177	Number of Matching Subsequences Array, Hash Table, String, Binary Search, Dynamic Programming, Trie, Sorting	Medium	40	0.5%
178	Verifying an Alien Dictionary Array, Hash Table, String	Easy	40	0.6%
179	Minimum Cost For Tickets Array, Dynamic Programming	Medium	40	0.7%
180	Collect Coins in a Tree Array, Tree, Graph Theory, Topological Sort	Hard	40	0.4%
181	Design Memory Allocator Array, Hash Table, Design, Simulation	Medium	40	0.5%
182	Basic Calculator II Math, String, Stack	Medium	40	0.5%
183	Longest Palindromic Substring Two Pointers, String, Dynamic Programming	Medium	37	0.4%
184	Find First and Last Position of Element in Sorted Array Array, Binary Search	Medium	37	0.5%
185	Binary Tree Maximum Path Sum Dynamic Programming, Tree, Depth-First Search, Binary Tree	Hard	37	0.4%
186	The Skyline Problem Array, Divide and Conquer, Binary Indexed Tree, Segment Tree, Sweep Line, Sorting, Heap (Priority Queue), Ordered Set	Hard	37	0.5%
187	Longest Increasing Path in a Matrix Array, Dynamic Programming, Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort, Memoization, Matrix	Hard	37	0.6%
188	Reconstruct Itinerary Array, String, Depth-First Search, Graph Theory, Sorting, Heap (Priority Queue), Eulerian Circuit	Hard	37	0.4%
189	LFU Cache Hash Table, Linked List, Design, Doubly-Linked List	Hard	37	0.5%
190	Task Scheduler Array, Hash Table, Greedy, Sorting, Heap (Priority Queue), Counting	Medium	37	0.6%
191	Sliding Puzzle Array, Dynamic Programming, Backtracking, Breadth-First Search, Memoization, Matrix	Hard	37	0.7%
192	Min Cost to Connect All Points Array, Union-Find, Graph Theory, Minimum Spanning Tree	Medium	37	0.7%
193	Most Profitable Path in a Tree Array, Tree, Depth-First Search, Breadth-First Search, Graph Theory	Medium	37	0.7%
194	Brightest Position on Street Array, Sorting, Prefix Sum, Ordered Set	Medium	37	0.6%
195	Number of Adjacent Elements With the Same Color Array	Medium	37	0.6%
196	Number of Provinces Depth-First Search, Breadth-First Search, Union-Find, Graph Theory	Medium	37	0.7%
197	24 Game Array, Math, Backtracking	Hard	37	0.6%
198	Maximum Points You Can Obtain from Cards Array, Sliding Window, Prefix Sum	Medium	37	0.6%
199	Burst Balloons Array, Dynamic Programming	Hard	37	0.6%
200	Maximum Number of Points From Grid Queries Array, Two Pointers, Breadth-First Search, Union-Find, Sorting, Heap (Priority Queue), Matrix	Hard	37	0.6%
201	Longest Common Prefix Array, String, Trie	Easy	32	0.5%
202	Next Permutation Array, Two Pointers	Medium	32	0.5%
203	Longest Valid Parentheses String, Dynamic Programming, Stack	Hard	32	0.4%
204	Permutations Array, Backtracking	Medium	32	0.8%
205	Maximum Subarray Array, Divide and Conquer, Dynamic Programming	Medium	32	0.5%
206	Minimum Path Sum Array, Dynamic Programming, Matrix	Medium	32	0.7%
207	Find Minimum in Rotated Sorted Array Array, Binary Search	Medium	32	0.5%
208	Shortest Palindrome String, Rolling Hash, String Matching, Hash Function	Hard	32	0.4%
209	Move Zeroes Array, Two Pointers	Easy	32	0.6%
210	Walls and Gates Array, Breadth-First Search, Matrix	Medium	32	0.6%
211	Subarray Sum Equals K Array, Hash Table, Prefix Sum	Medium	32	0.5%
212	Is Graph Bipartite? Depth-First Search, Breadth-First Search, Union-Find, Graph Theory	Medium	32	0.6%
213	Cheapest Flights Within K Stops Dynamic Programming, Depth-First Search, Breadth-First Search, Graph Theory, Heap (Priority Queue), Shortest Path	Medium	32	0.4%
214	Exam Room Design, Heap (Priority Queue), Ordered Set	Medium	32	0.4%
215	Interval List Intersections Array, Two Pointers, Sweep Line	Medium	32	0.7%
216	Subarrays with K Different Integers Array, Hash Table, Sliding Window, Counting	Hard	32	0.7%
217	Count Nice Pairs in an Array Array, Hash Table, Math, Counting	Medium	32	0.5%
218	Maximum Earnings From Taxi Array, Hash Table, Binary Search, Dynamic Programming, Sorting	Medium	32	0.5%
219	Number of Flowers in Full Bloom Array, Hash Table, Binary Search, Sorting, Prefix Sum, Ordered Set	Hard	32	0.6%
220	Find the Length of the Longest Common Prefix Array, Hash Table, String, Trie	Medium	32	0.6%
221	Smallest String With Swaps Array, Hash Table, String, Depth-First Search, Breadth-First Search, Union-Find, Sorting	Medium	32	0.6%
222	Word Ladder II Hash Table, String, Backtracking, Breadth-First Search	Hard	32	0.3%
223	Add Digits Math, Simulation, Number Theory	Easy	32	0.7%
224	Design File System Hash Table, String, Design, Trie	Medium	32	0.7%
225	Water and Jug Problem Math, Depth-First Search, Breadth-First Search	Medium	32	0.5%
226	Rotated Digits Math, Dynamic Programming	Medium	32	0.6%
227	Detonate the Maximum Bombs Array, Math, Depth-First Search, Breadth-First Search, Graph Theory, Geometry	Medium	32	0.5%
228	Find Critical and Pseudo-Critical Edges in Minimum Spanning Tree Union-Find, Graph Theory, Sorting, Minimum Spanning Tree, Strongly Connected Component	Hard	32	0.7%
229	Replace Non-Coprime Numbers in Array Array, Math, Stack, Number Theory	Hard	32	0.6%
230	Maximum Profit in Job Scheduling Array, Binary Search, Dynamic Programming, Sorting	Hard	32	0.5%
231	Shortest Path to Get All Keys Array, Bit Manipulation, Breadth-First Search, Matrix	Hard	32	0.5%
232	Maximum Number of Alloys Array, Binary Search	Medium	32	0.4%
233	Median of Two Sorted Arrays Array, Binary Search, Divide and Conquer	Hard	27	0.5%
234	Reverse Integer Math	Medium	27	0.3%
235	Valid Parentheses String, Stack	Easy	27	0.4%
236	Remove Element Array, Two Pointers	Easy	27	0.6%
237	Sqrt(x) Math, Binary Search	Easy	27	0.4%
238	Longest Repeating Character Replacement Hash Table, String, Sliding Window	Medium	27	0.6%
239	Find Eventual Safe States Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort	Medium	27	0.7%
240	Capacity To Ship Packages Within D Days Array, Binary Search	Medium	27	0.7%
241	Analyze User Website Visit Pattern Array, Hash Table, String, Sorting	Medium	27	0.4%
242	Minimum Number of Taps to Open to Water a Garden Array, Dynamic Programming, Greedy	Hard	27	0.5%
243	Design Parking System Design, Simulation, Counting	Easy	27	0.9%
244	Furthest Building You Can Reach Array, Greedy, Heap (Priority Queue)	Medium	27	0.5%
245	Frequency of the Most Frequent Element Array, Binary Search, Greedy, Sliding Window, Sorting, Prefix Sum	Medium	27	0.4%
246	Count the Number of Good Subarrays Array, Hash Table, Sliding Window	Medium	27	0.7%
247	Put Marbles in Bags Array, Greedy, Sorting, Heap (Priority Queue)	Hard	27	0.7%
248	Minimum Absolute Difference Between Elements With Constraint Array, Binary Search, Ordered Set	Medium	27	0.4%
249	Find the Most Competitive Subsequence Array, Stack, Greedy, Monotonic Stack	Medium	27	0.5%
250	Design Browser History Array, Linked List, Stack, Design, Doubly-Linked List, Data Stream	Medium	27	0.8%
251	Design Search Autocomplete System String, Depth-First Search, Design, Trie, Sorting, Heap (Priority Queue), Data Stream	Hard	27	0.5%
252	Meeting Scheduler Array, Two Pointers, Sorting	Medium	27	0.6%
253	Maximum Frequency Stack Hash Table, Stack, Design, Ordered Set	Hard	27	0.7%
254	Design a Text Editor Linked List, String, Stack, Design, Simulation, Doubly-Linked List	Hard	27	0.5%
255	Remove Comments Array, String	Medium	27	0.4%
256	Surrounded Regions Array, Depth-First Search, Breadth-First Search, Union-Find, Matrix	Medium	27	0.5%
257	Number of Subarrays That Match a Pattern I Array, Rolling Hash, String Matching, Hash Function	Medium	27	0.7%
258	Cache With Time Limit	Medium	27	0.8%
259	Add Strings Math, String, Simulation	Easy	27	0.5%
260	Largest 1-Bordered Square Array, Dynamic Programming, Matrix	Medium	27	0.5%
261	Graph Connectivity With Threshold Array, Math, Union-Find, Number Theory	Hard	27	0.5%
262	Simplify Path String, Stack	Medium	27	0.5%
263	Shortest Path in Binary Matrix Array, Breadth-First Search, Matrix	Medium	27	0.5%
264	Random Point in Non-overlapping Rectangles Array, Math, Binary Search, Reservoir Sampling, Prefix Sum, Ordered Set, Randomized	Medium	27	0.4%
265	Maximum Number of Events That Can Be Attended Array, Greedy, Sorting, Heap (Priority Queue)	Medium	27	0.4%
266	Count Primes Array, Math, Enumeration, Number Theory	Medium	27	0.4%
267	IPO Array, Greedy, Sorting, Heap (Priority Queue)	Hard	27	0.5%
268	Design A Leaderboard Hash Table, Design, Sorting	Medium	27	0.7%
269	Minimum Jumps to Reach End via Prime Teleportation Array, Hash Table, Math, Breadth-First Search, Number Theory	Medium	27	0.4%
270	Minimum Knight Moves Breadth-First Search	Medium	27	0.4%
271	Count the Number of Infection Sequences Array, Math, Combinatorics	Hard	27	0.4%
272	Binary Searchable Numbers in an Unsorted Array Array, Binary Search, Stack, Monotonic Stack	Medium	27	0.6%
273	Add Two Numbers Linked List, Math, Recursion	Medium	19	0.5%
274	Longest Substring Without Repeating Characters Hash Table, String, Sliding Window	Medium	19	0.4%
275	Container With Most Water Array, Two Pointers, Greedy	Medium	19	0.6%
276	Remove Duplicates from Sorted Array Array, Two Pointers	Easy	19	0.6%
277	Climbing Stairs Math, Dynamic Programming, Memoization	Easy	19	0.5%
278	Set Matrix Zeroes Array, Hash Table, Matrix	Medium	19	0.6%
279	Kth Largest Element in an Array Array, Divide and Conquer, Sorting, Heap (Priority Queue), Quickselect	Medium	19	0.7%
280	Search a 2D Matrix II Array, Binary Search, Divide and Conquer, Matrix	Medium	19	0.6%
281	Longest Increasing Subsequence Array, Binary Search, Dynamic Programming	Medium	19	0.6%
282	Patching Array Array, Greedy	Hard	19	0.5%
283	Matchsticks to Square Array, Dynamic Programming, Backtracking, Bit Manipulation, Bitmask	Medium	19	0.4%
284	Predict the Winner Array, Math, Dynamic Programming, Recursion, Game Theory	Medium	19	0.6%
285	Next Greater Element I Array, Hash Table, Stack, Monotonic Stack	Easy	19	0.8%
286	Freedom Trail String, Dynamic Programming, Depth-First Search, Breadth-First Search	Hard	19	0.6%
287	01 Matrix Array, Dynamic Programming, Breadth-First Search, Matrix	Medium	19	0.5%
288	Find K Closest Elements Array, Two Pointers, Binary Search, Sliding Window, Sorting, Heap (Priority Queue)	Medium	19	0.5%
289	Candy Crush Array, Two Pointers, Matrix, Simulation	Medium	19	0.8%
290	Swim in Rising Water Array, Binary Search, Depth-First Search, Breadth-First Search, Union-Find, Heap (Priority Queue), Matrix	Hard	19	0.7%
291	Possible Bipartition Depth-First Search, Breadth-First Search, Union-Find, Graph Theory	Medium	19	0.5%
292	Stone Game II Array, Math, Dynamic Programming, Prefix Sum, Game Theory	Medium	19	0.7%
293	Simple Bank System Array, Hash Table, Design, Simulation	Medium	19	0.7%
294	Time Needed to Buy Tickets Array, Queue, Simulation	Easy	19	0.7%
295	Amount of New Area Painted Each Day Array, Segment Tree, Ordered Set	Hard	19	0.6%
296	Amount of Time for Binary Tree to Be Infected Hash Table, Tree, Depth-First Search, Breadth-First Search, Binary Tree	Medium	19	0.7%
297	House Robber II Array, Dynamic Programming	Medium	19	0.5%
298	Paint House Array, Dynamic Programming	Medium	19	0.6%
299	Get Biggest Three Rhombus Sums in a Grid Array, Math, Sorting, Heap (Priority Queue), Matrix, Prefix Sum	Medium	19	0.7%
300	Meeting Rooms Array, Sorting	Easy	19	0.6%
301	Find the Celebrity Two Pointers, Graph Theory, Interactive	Medium	19	0.5%
302	Count Different Palindromic Subsequences String, Dynamic Programming	Hard	19	0.5%
303	Spiral Matrix III Array, Matrix, Simulation	Medium	19	0.8%
304	Minimize Malware Spread Array, Hash Table, Depth-First Search, Breadth-First Search, Union-Find, Graph Theory	Hard	19	0.4%
305	Minimize Malware Spread II Array, Hash Table, Depth-First Search, Breadth-First Search, Union-Find, Graph Theory	Hard	19	0.5%
306	Count Palindromic Subsequences String, Dynamic Programming	Hard	19	0.4%
307	Count Prefix and Suffix Pairs II Array, String, Trie, Rolling Hash, String Matching, Hash Function	Hard	19	0.3%
308	Number of Distinct Substrings in a String String, Trie, Rolling Hash, Suffix Array, Hash Function	Medium	19	0.6%
309	Promise Pool	Medium	19	0.8%
310	Maximum Manhattan Distance After K Changes Hash Table, Math, String, Counting	Medium	19	0.5%
311	Shortest Path in a Grid with Obstacles Elimination Array, Breadth-First Search, Matrix	Hard	19	0.5%
312	Valid Palindrome II Two Pointers, String, Greedy	Easy	19	0.4%
313	Maximize Sum Of Array After K Negations Array, Greedy, Sorting	Easy	19	0.5%
314	Number of Subarrays with Bounded Maximum Array, Two Pointers	Medium	19	0.6%
315	Design Snake Game Array, Hash Table, Design, Queue, Simulation	Medium	19	0.4%
316	Reverse Nodes in k-Group Linked List, Recursion	Hard	19	0.7%
317	Find the Maximum Length of Valid Subsequence II Array, Dynamic Programming	Medium	19	0.6%
318	Integer Replacement Dynamic Programming, Greedy, Bit Manipulation, Memoization	Medium	19	0.4%
319	2 Keys Keyboard Math, Dynamic Programming	Medium	19	0.6%
320	Binary Tree Longest Consecutive Sequence II Tree, Depth-First Search, Binary Tree	Medium	19	0.5%
321	Maximum Average Subarray I Array, Sliding Window	Easy	19	0.5%
322	Ones and Zeroes Array, String, Dynamic Programming	Medium	19	0.5%
323	Count Integers in Intervals Design, Segment Tree, Ordered Set	Hard	19	0.4%
324	Human Traffic of Stadium Database	Hard	19	0.5%
325	Repeated String Match String, String Matching	Medium	19	0.4%
326	Insert Delete GetRandom O(1) - Duplicates allowed Array, Hash Table, Math, Design, Randomized	Hard	19	0.4%
327	Find the Safest Path in a Grid Array, Binary Search, Breadth-First Search, Union-Find, Heap (Priority Queue), Matrix	Medium	19	0.5%
328	Closest Binary Search Tree Value Binary Search, Tree, Depth-First Search, Binary Search Tree, Binary Tree	Easy	19	0.5%
329	Accounts Merge Array, Hash Table, String, Depth-First Search, Breadth-First Search, Union-Find, Sorting	Medium	19	0.6%
330	Minimum Difference in Sums After Removal of Elements Array, Dynamic Programming, Heap (Priority Queue)	Hard	19	0.7%
331	Linked List Components Array, Hash Table, Linked List	Medium	19	0.6%
332	Count Binary Substrings Two Pointers, String	Easy	19	0.7%
333	Bomb Enemy Array, Dynamic Programming, Matrix	Medium	19	0.5%
334	Find All People With Secret Depth-First Search, Breadth-First Search, Union-Find, Graph Theory, Sorting	Hard	19	0.5%
335	Magnetic Force Between Two Balls Array, Binary Search, Sorting	Medium	19	0.7%
336	Rearranging Fruits Array, Hash Table, Greedy, Sort	Hard	19	0.6%
337	Process Restricted Friend Requests Union-Find, Graph Theory	Hard	19	0.6%
338	Longest Subsequence With Limited Sum Array, Binary Search, Greedy, Sorting, Prefix Sum	Easy	19	0.7%
339	Vertical Order Traversal of a Binary Tree Hash Table, Tree, Depth-First Search, Breadth-First Search, Sorting, Binary Tree	Hard	19	0.5%
340	Checking Existence of Edge Length Limited Paths Array, Two Pointers, Union-Find, Graph Theory, Sorting	Hard	19	0.6%
341	Find K-th Smallest Pair Distance Array, Two Pointers, Binary Search, Sorting	Hard	19	0.5%
342	Shortest Distance from All Buildings Array, Breadth-First Search, Matrix	Hard	19	0.4%
343	Painting a Grid With Three Different Colors Dynamic Programming	Hard	19	0.8%
344	Find All Anagrams in a String Hash Table, String, Sliding Window	Medium	19	0.5%
345	Minimize the Maximum Edge Weight of Graph Binary Search, Depth-First Search, Breadth-First Search, Graph Theory, Shortest Path	Medium	19	0.4%
346	Fizz Buzz Math, String, Simulation	Easy	19	0.8%
347	Find a Peak Element II Array, Binary Search, Matrix	Medium	19	0.6%
348	Next Greater Element II Array, Stack, Monotonic Stack	Medium	19	0.7%
349	Graph Valid Tree Depth-First Search, Breadth-First Search, Union-Find, Graph Theory	Medium	19	0.5%
350	Populating Next Right Pointers in Each Node II Linked List, Tree, Depth-First Search, Breadth-First Search, Binary Tree	Medium	19	0.6%
351	Minimum Fuel Cost to Report to the Capital Tree, Depth-First Search, Breadth-First Search, Graph Theory	Medium	19	0.7%
352	Number of Ways to Form a Target String Given a Dictionary Array, String, Dynamic Programming	Hard	19	0.6%
353	Search a 2D Matrix Array, Binary Search, Matrix	Medium	19	0.5%
354	Search Suggestions System Array, String, Binary Search, Trie, Sorting, Heap (Priority Queue)	Medium	19	0.7%
355	Zero Array Transformation II Array, Two Pointers, Binary Search, Prefix Sum	Medium	19	0.4%
356	Remove Sub-Folders from the Filesystem Array, String, Depth-First Search, Trie	Medium	19	0.8%
357	Goat Latin String	Easy	19	0.7%
358	Make Lexicographically Smallest Array by Swapping Elements Array, Union-Find, Sorting	Medium	19	0.6%
359	Number of Wonderful Substrings Hash Table, String, Bit Manipulation, Prefix Sum	Medium	19	0.7%
360	Minimum Number of Refueling Stops Array, Dynamic Programming, Greedy, Heap (Priority Queue)	Hard	19	0.4%
361	Sort Colors Array, Two Pointers, Sorting	Medium	19	0.7%
362	Design Twitter Hash Table, Linked List, Design, Heap (Priority Queue)	Medium	19	0.4%

How to read this list

The tabs at the top split the questions by how recently people said they were asked in interviews. "Last 30 Days" is the past month, "Last 3 Months" is the past quarter, and so on. "All Time" is every question on record for this company.

Frequency is a score from 0 to 100 for how often a question showed up in that time window. A higher number means it came up more often, so the list starts with the most common questions first. Acceptance is the share of submissions that pass on LeetCode. Click any question to open it on LeetCode.