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#	Title	Difficulty	Frequency
1	Two Sum	Easy	31.05
2	Add Two Numbers	Medium	3.81
3	Longest Substring Without Repeating Characters	Medium	0.39
4	Median of Two Sorted Arrays	Hard	19.17
5	Longest Palindromic Substring	Medium	7.01
7	Reverse Integer	Medium	7.19
11	Container With Most Water	Medium	2.57
12	Integer to Roman	Medium	5.16
13	Roman to Integer	Easy	40.39
14	Longest Common Prefix	Easy	4.05
15	3Sum	Medium	8.91
17	Letter Combinations of a Phone Number	Medium	3.47
18	4Sum	Medium	2.36
19	Remove Nth Node From End of List	Medium	2.22
20	Valid Parentheses	Easy	8.93
21	Merge Two Sorted Lists	Easy	1.42
22	Generate Parentheses	Medium	3.24
23	Merge k Sorted Lists	Hard	22.37
25	Reverse Nodes in k-Group	Hard	8.93
26	Remove Duplicates from Sorted Array	Easy	0.47
27	Remove Element	Easy	1.27
31	Next Permutation	Medium	3.53
33	Search in Rotated Sorted Array	Medium	0.33
34	Find First and Last Position of Element in Sorted Array	Medium	1.09
35	Search Insert Position	Easy	1.86
39	Combination Sum	Medium	1.35
48	Rotate Image	Medium	7.92
50	Pow(x, n)	Medium	2.25
52	N-Queens II	Hard	8.02
55	Jump Game	Medium	1.01
56	Merge Intervals	Medium	21.31
57	Insert Interval	Medium	5.11
62	Unique Paths	Medium	25.00
68	Text Justification	Hard	19.71
70	Climbing Stairs	Easy	1.49
78	Subsets	Medium	3.31
86	Partition List	Medium	6.12
88	Merge Sorted Array	Easy	3.08
104	Maximum Depth of Binary Tree	Easy	0.77
121	Best Time to Buy and Sell Stock	Easy	3.21
128	Longest Consecutive Sequence	Medium	5.30
136	Single Number	Easy	4.08
137	Single Number II	Medium	12.89
140	Word Break II	Hard	12.40
146	LRU Cache	Medium	29.14
150	Evaluate Reverse Polish Notation	Medium	2.15
185	Department Top Three Salaries	Hard	6.49
189	Rotate Array	Medium	0.75
198	House Robber	Medium	6.92
200	Number of Islands	Medium	8.89
207	Course Schedule	Medium	13.26
208	Implement Trie (Prefix Tree)	Medium	2.84
210	Course Schedule II	Medium	6.27
212	Word Search II	Hard	5.32
213	House Robber II	Medium	16.47
215	Kth Largest Element in an Array	Medium	3.22
217	Contains Duplicate	Easy	1.88
224	Basic Calculator	Hard	7.58
238	Product of Array Except Self	Medium	0.67
239	Sliding Window Maximum	Hard	4.63
253	Meeting Rooms II	Medium	39.76
258	Add Digits	Easy	10.80
283	Move Zeroes	Easy	0.82
300	Longest Increasing Subsequence	Medium	1.41
312	Burst Balloons	Hard	7.91
315	Count of Smaller Numbers After Self	Hard	9.44
322	Coin Change	Medium	1.16
329	Longest Increasing Path in a Matrix	Hard	15.44
359	Logger Rate Limiter	Easy	213.85
365	Water and Jug Problem	Medium	26.29
366	Find Leaves of Binary Tree	Medium	58.98
384	Shuffle an Array	Medium	41.89
394	Decode String	Medium	3.79
402	Remove K Digits	Medium	6.17
415	Add Strings	Easy	6.17
424	Longest Repeating Character Replacement	Medium	2.06
454	4Sum II	Medium	30.75
485	Max Consecutive Ones	Easy	1.98
540	Single Element in a Sorted Array	Medium	5.98
542	01 Matrix	Medium	4.02
554	Brick Wall	Medium	22.83
560	Subarray Sum Equals K	Medium	1.77
567	Permutation in String	Medium	2.42
647	Palindromic Substrings	Medium	3.97
685	Redundant Connection II	Hard	24.07
692	Top K Frequent Words	Medium	16.08
715	Range Module	Hard	177.88
739	Daily Temperatures	Medium	2.20
759	Employee Free Time	Hard	75.38
427	Construct Quad Tree	Medium	45.08
808	Soup Servings	Medium	26.29
707	Design Linked List	Medium	6.98
833	Find And Replace in String	Medium	68.76
489	Robot Room Cleaner	Hard	51.08
837	New 21 Game	Medium	44.18
843	Guess the Word	Hard	118.34
844	Backspace String Compare	Easy	6.41
862	Shortest Subarray with Sum at Least K	Hard	34.16
863	All Nodes Distance K in Binary Tree	Medium	6.70
875	Koko Eating Bananas	Medium	1.83
876	Middle of the Linked List	Easy	1.24
528	Random Pick with Weight	Medium	13.05
934	Shortest Bridge	Medium	106.90
938	Range Sum of BST	Easy	14.93
958	Check Completeness of a Binary Tree	Medium	16.99
974	Subarray Sums Divisible by K	Medium	13.44
975	Odd Even Jump	Hard	140.51
987	Vertical Order Traversal of a Binary Tree	Hard	4.79
1007	Minimum Domino Rotations For Equal Row	Medium	37.83
1011	Capacity To Ship Packages Within D Days	Medium	10.92
1101	The Earliest Moment When Everyone Become Friends	Medium	71.02
1136	Parallel Courses	Medium	144.48
1110	Delete Nodes And Return Forest	Medium	180.43
1148	Article Views I	Easy	1.21
1207	Unique Number of Occurrences	Easy	6.16
1514	Path with Maximum Probability	Medium	16.43
1249	Minimum Remove to Make Valid Parentheses	Medium	22.88
1254	Number of Closed Islands	Medium	43.10
1376	Time Needed to Inform All Employees	Medium	15.97
1480	Running Sum of 1d Array	Easy	4.27
1509	Minimum Difference Between Largest and Smallest Value in Three Moves	Medium	5.05
1639	Number of Ways to Form a Target String Given a Dictionary	Hard	47.38
1672	Richest Customer Wealth	Easy	2.54
1679	Max Number of K-Sum Pairs	Medium	3.83
1768	Merge Strings Alternately	Easy	4.22
1803	Count Pairs With XOR in a Range	Hard	84.73
1825	Finding MK Average	Hard	76.21
1834	Single-Threaded CPU	Medium	59.38
1857	Largest Color Value in a Directed Graph	Hard	32.54
2007	Find Original Array From Doubled Array	Medium	62.80
1971	Find if Path Exists in Graph	Easy	13.60
2013	Detect Squares	Medium	50.50
2101	Detonate the Maximum Bombs	Medium	193.40
2235	Add Two Integers	Easy	2.67
2332	The Latest Time to Catch a Bus	Medium	70.44
2402	Meeting Rooms III	Hard	223.19
2407	Longest Increasing Subsequence II	Hard	33.65
2448	Minimum Cost to Make Array Equal	Hard	32.81
2458	Height of Binary Tree After Subtree Removal Queries	Hard	236.85
2620	Counter	Easy	4.23
2667	Create Hello World Function	Easy	4.37
2713	Maximum Strictly Increasing Cells in a Matrix	Hard	166.65