Yandex

#	Title	Difficulty	Frequency
1	Two Sum	Easy	0.69
2	Add Two Numbers	Medium	0.62
3	Longest Substring Without Repeating Characters	Medium	9.43
5	Longest Palindromic Substring	Medium	0.80
20	Valid Parentheses	Easy	4.47
27	Remove Element	Easy	0.56
33	Search in Rotated Sorted Array	Medium	0.08
42	Trapping Rain Water	Hard	2.75
56	Merge Intervals	Medium	2.60
71	Simplify Path	Medium	3.85
76	Minimum Window Substring	Hard	2.02
93	Restore IP Addresses	Medium	15.01
98	Validate Binary Search Tree	Medium	13.19
101	Symmetric Tree	Easy	3.51
104	Maximum Depth of Binary Tree	Easy	0.77
121	Best Time to Buy and Sell Stock	Easy	7.09
124	Binary Tree Maximum Path Sum	Hard	2.00
125	Valid Palindrome	Easy	11.48
135	Candy	Hard	7.61
146	LRU Cache	Medium	8.12
150	Evaluate Reverse Polish Notation	Medium	2.15
155	Min Stack	Medium	3.22
161	One Edit Distance	Medium	184.47
169	Majority Element	Easy	0.65
200	Number of Islands	Medium	8.89
205	Isomorphic Strings	Easy	14.50
206	Reverse Linked List	Easy	2.55
228	Summary Ranges	Easy	126.56
234	Palindrome Linked List	Easy	3.43
238	Product of Array Except Self	Medium	0.67
239	Sliding Window Maximum	Hard	4.63
242	Valid Anagram	Easy	0.52
283	Move Zeroes	Easy	18.73
300	Longest Increasing Subsequence	Medium	3.14
301	Remove Invalid Parentheses	Hard	14.73
340	Longest Substring with At Most K Distinct Characters	Medium	49.64
347	Top K Frequent Elements	Medium	0.98
350	Intersection of Two Arrays II	Easy	22.06
356	Line Reflection	Medium	289.38
362	Design Hit Counter	Medium	99.78
380	Insert Delete GetRandom O(1)	Medium	47.52
438	Find All Anagrams in a String	Medium	18.81
443	String Compression	Medium	25.49
485	Max Consecutive Ones	Easy	4.40
487	Max Consecutive Ones II	Medium	52.30
560	Subarray Sum Equals K	Medium	19.76
567	Permutation in String	Medium	26.24
657	Robot Return to Origin	Easy	13.26
658	Find K Closest Elements	Medium	84.40
680	Valid Palindrome II	Easy	16.81
692	Top K Frequent Words	Medium	27.01
763	Partition Labels	Medium	8.57
849	Maximize Distance to Closest Person	Medium	166.93
977	Squares of a Sorted Array	Easy	60.40
1329	Sort the Matrix Diagonally	Medium	30.31
2215	Find the Difference of Two Arrays	Easy	30.70
1493	Longest Subarray of 1's After Deleting One Element	Medium	239.56
2241	Design an ATM Machine	Medium	136.33
2636	Promise Pool	Medium	234.29
2625	Flatten Deeply Nested Array	Medium	67.79
2657	Find the Prefix Common Array of Two Arrays	Medium	25.62
2694	Event Emitter	Medium	34.83