EPAM Systems LeetCode Questions

46 questions all-time · 16 easy · 27 medium · 3 hard

#	Problem	Difficulty	Frequency	Acceptance
1	Two Sum Array, Hash Table	Easy	100	0.6%
2	Longest Substring Without Repeating Characters Hash Table, String, Sliding Window	Medium	98	0.4%
3	Minimum Operations to Make a Uni-Value Grid Array, Math, Sorting, Matrix	Medium	94	0.7%
4	Valid Parentheses String, Stack	Easy	86	0.4%
5	Longest Palindromic Substring Two Pointers, String, Dynamic Programming	Medium	83	0.4%
6	Longest Common Prefix Array, String, Trie	Easy	83	0.5%
7	Move Zeroes Array, Two Pointers	Easy	83	0.6%
8	Merge Sorted Array Array, Two Pointers, Sorting	Easy	80	0.6%
9	Valid Anagram Hash Table, String, Sorting	Easy	80	0.7%
10	Group Anagrams Array, Hash Table, String, Sorting	Medium	75	0.7%
11	Best Time to Buy and Sell Stock Array, Dynamic Programming	Easy	75	0.6%
12	Rotate Array Array, Math, Two Pointers	Medium	75	0.5%
13	3Sum Array, Two Pointers, Sorting	Medium	63	0.4%
14	Trapping Rain Water Array, Two Pointers, Dynamic Programming, Stack, Monotonic Stack	Hard	63	0.7%
15	House Robber Array, Dynamic Programming	Medium	63	0.5%
16	Partition Equal Subset Sum Array, Dynamic Programming	Medium	63	0.5%
17	Longest Consecutive Sequence Array, Hash Table, Union-Find	Medium	63	0.5%
18	String Compression Two Pointers, String	Medium	63	0.6%
19	Reverse String Two Pointers, String	Easy	63	0.8%
20	First Unique Character in a String Hash Table, String, Queue, Counting	Easy	63	0.7%
21	Merge Intervals Array, Sorting	Medium	63	0.5%
22	Generate Parentheses String, Dynamic Programming, Backtracking	Medium	63	0.8%
23	Reverse Vowels of a String Two Pointers, String	Easy	63	0.6%
24	Add Two Numbers Linked List, Math, Recursion	Medium	53	0.5%
25	Palindrome Number Math	Easy	53	0.6%
26	Maximum Difference Between Node and Ancestor Tree, Depth-First Search, Binary Tree	Medium	53	0.8%
27	Reverse Integer Math	Medium	53	0.3%
28	Two Sum II - Input Array Is Sorted Array, Two Pointers, Binary Search	Medium	53	0.7%
29	Pow(x, n) Math, Recursion	Medium	53	0.4%
30	Duplicate Emails Database	Easy	53	0.7%
31	Count Salary Categories Database	Medium	53	0.6%
32	Multiply Strings Math, String, Simulation	Medium	53	0.4%
33	Maximum Subarray Array, Divide and Conquer, Dynamic Programming	Medium	53	0.5%
34	Reverse Words in a String Two Pointers, String	Medium	53	0.6%
35	Unique Paths Math, Dynamic Programming, Combinatorics	Medium	53	0.7%
36	Edit Distance String, Dynamic Programming	Medium	53	0.6%
37	Roman to Integer Hash Table, Math, String	Easy	53	0.7%
38	Counter	Easy	53	0.8%
39	Reverse Linked List Linked List, Recursion	Easy	53	0.8%
40	Sort Characters By Frequency Hash Table, String, Sorting, Heap (Priority Queue), Bucket Sort, Counting	Medium	53	0.8%
41	Top K Frequent Elements Array, Hash Table, Divide and Conquer, Sorting, Heap (Priority Queue), Bucket Sort, Counting, Quickselect	Medium	53	0.7%
42	Kth Largest Element in an Array Array, Divide and Conquer, Sorting, Heap (Priority Queue), Quickselect	Medium	53	0.7%
43	First Missing Positive Array, Hash Table	Hard	53	0.4%
44	Median of Two Sorted Arrays Array, Binary Search, Divide and Conquer	Hard	53	0.5%
45	Merge Two Sorted Lists Linked List, Recursion	Easy	53	0.7%
46	LRU Cache Hash Table, Linked List, Design, Doubly-Linked List	Medium	53	0.5%

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.