Bloomberg

#	Title	Difficulty	Frequency
1	Two Sum	Easy	0.69
2	Add Two Numbers	Medium	1.39
3	Longest Substring Without Repeating Characters	Medium	7.70
4	Median of Two Sorted Arrays	Hard	6.32
5	Longest Palindromic Substring	Medium	7.01
9	Palindrome Number	Easy	0.47
11	Container With Most Water	Medium	1.45
13	Roman to Integer	Easy	8.10
14	Longest Common Prefix	Easy	1.48
15	3Sum	Medium	2.30
16	3Sum Closest	Medium	3.13
17	Letter Combinations of a Phone Number	Medium	6.08
18	4Sum	Medium	5.23
20	Valid Parentheses	Easy	1.48
24	Swap Nodes in Pairs	Medium	16.99
26	Remove Duplicates from Sorted Array	Easy	0.47
27	Remove Element	Easy	0.56
33	Search in Rotated Sorted Array	Medium	0.08
34	Find First and Last Position of Element in Sorted Array	Medium	1.09
42	Trapping Rain Water	Hard	10.58
45	Jump Game II	Medium	1.46
46	Permutations	Medium	2.99
48	Rotate Image	Medium	2.93
53	Maximum Subarray	Medium	1.57
56	Merge Intervals	Medium	7.07
58	Length of Last Word	Easy	0.98
66	Plus One	Easy	0.92
67	Add Binary	Easy	1.84
70	Climbing Stairs	Easy	4.10
74	Search a 2D Matrix	Medium	0.67
79	Word Search	Medium	4.50
90	Subsets II	Medium	2.24
96	Unique Binary Search Trees	Medium	5.72
98	Validate Binary Search Tree	Medium	1.14
112	Path Sum	Easy	2.39
118	Pascal's Triangle	Easy	3.60
121	Best Time to Buy and Sell Stock	Easy	2.24
122	Best Time to Buy and Sell Stock II	Medium	1.36
125	Valid Palindrome	Easy	0.60
128	Longest Consecutive Sequence	Medium	3.43
130	Surrounded Regions	Medium	2.92
136	Single Number	Easy	1.04
139	Word Break	Medium	5.11
140	Word Break II	Hard	42.40
143	Reorder List	Medium	2.68
146	LRU Cache	Medium	2.09
155	Min Stack	Medium	1.44
169	Majority Element	Easy	0.65
200	Number of Islands	Medium	5.78
203	Remove Linked List Elements	Easy	2.81
206	Reverse Linked List	Easy	1.44
207	Course Schedule	Medium	1.56
211	Design Add and Search Words Data Structure	Medium	4.96
230	Kth Smallest Element in a BST	Medium	1.96
231	Power of Two	Easy	2.15
234	Palindrome Linked List	Easy	3.43
236	Lowest Common Ancestor of a Binary Tree	Medium	11.98
238	Product of Array Except Self	Medium	2.67
268	Missing Number	Easy	1.13
300	Longest Increasing Subsequence	Medium	1.41
308	Range Sum Query 2D - Mutable	Hard	157.92
347	Top K Frequent Elements	Medium	2.20
380	Insert Delete GetRandom O(1)	Medium	8.21
392	Is Subsequence	Easy	2.77
394	Decode String	Medium	67.56
405	Convert a Number to Hexadecimal	Easy	22.70
560	Subarray Sum Equals K	Medium	1.77
570	Managers with at Least 5 Direct Reports	Medium	2.53
611	Valid Triangle Number	Medium	19.97
740	Delete and Earn	Medium	7.11
808	Soup Servings	Medium	26.29
852	Peak Index in a Mountain Array	Medium	6.55
908	Smallest Range I	Easy	35.77
1029	Two City Scheduling	Medium	38.78
1035	Uncrossed Lines	Medium	16.43
1244	Design A Leaderboard	Medium	46.26
1274	Number of Ships in a Rectangle	Hard	216.59
1207	Unique Number of Occurrences	Easy	2.79
1498	Number of Subsequences That Satisfy the Given Sum Condition	Medium	33.77
1799	Maximize Score After N Operations	Hard	58.78
1802	Maximum Value at a Given Index in a Bounded Array	Medium	21.02
2149	Rearrange Array Elements by Sign	Medium	4.52
2583	Kth Largest Sum in a Binary Tree	Medium	26.47
2621	Sleep	Easy	4.98
2646	Minimize the Total Price of the Trips	Hard	99.26