Interview Intel · Problems

The 1,923 problems
every coding interview recycles.

1,923 unique LeetCode-style problems tagged with which of 469 companies actually asks them. Click any problem to see frequency, company tags, and the honest play.

⏵ Most universally asked (top 60 by # companies)

#	Problem	Diff	# Companies
01	Best Time to Buy and Sell Stock	EASY	120
02	Two Sum	EASY	115
03	LRU Cache	MEDIUM	109
04	Valid Parentheses	EASY	94
05	Longest Substring Without Repeating Characters	MEDIUM	92
06	Merge Intervals	MEDIUM	89
07	Number of Islands	MEDIUM	86
08	Trapping Rain Water	HARD	81
09	Group Anagrams	MEDIUM	80
10	Longest Palindromic Substring	MEDIUM	74
11	3Sum	MEDIUM	66
12	Maximum Subarray	MEDIUM	55
13	Container With Most Water	MEDIUM	52
14	Search in Rotated Sorted Array	MEDIUM	51
15	Longest Common Prefix	EASY	49
16	Merge Sorted Array	EASY	47
17	Insert Delete GetRandom O(1)	MEDIUM	46
18	Spiral Matrix	MEDIUM	46
19	Top K Frequent Elements	MEDIUM	43
20	Median of Two Sorted Arrays	HARD	42
21	Merge k Sorted Lists	HARD	42
22	Merge Two Sorted Lists	EASY	42
23	Product of Array Except Self	MEDIUM	42
24	Kth Largest Element in an Array	MEDIUM	41
25	Meeting Rooms II	MEDIUM	41
26	First Missing Positive	HARD	40
27	Generate Parentheses	MEDIUM	40
28	Coin Change	MEDIUM	37
29	House Robber	MEDIUM	37
30	Letter Combinations of a Phone Number	MEDIUM	37
31	Add Two Numbers	MEDIUM	36
32	Climbing Stairs	EASY	36
33	Decode String	MEDIUM	36
34	Integer to Roman	MEDIUM	36
35	Longest Consecutive Sequence	MEDIUM	36
36	Roman to Integer	EASY	36
37	Jump Game	MEDIUM	35
38	Move Zeroes	EASY	35
39	Reverse Linked List	EASY	35
40	Rotate Image	MEDIUM	35
41	Word Search	MEDIUM	35
42	Best Time to Buy and Sell Stock II	MEDIUM	34
43	Course Schedule	MEDIUM	34
44	Rotting Oranges	MEDIUM	34
45	Sliding Window Maximum	HARD	34
46	Subarray Sum Equals K	MEDIUM	34
47	Text Justification	HARD	34
48	Course Schedule II	MEDIUM	33
49	Min Stack	MEDIUM	33
50	Next Permutation	MEDIUM	33
51	Palindrome Number	EASY	33
52	Sort Colors	MEDIUM	33
53	Valid Anagram	EASY	33
54	Valid Palindrome	EASY	32
55	Valid Sudoku	MEDIUM	32
56	Find First and Last Position of Element in Sorted Array	MEDIUM	31
57	Find Median from Data Stream	HARD	31
58	Jump Game II	MEDIUM	31
59	Minimum Window Substring	HARD	31
60	Word Break	MEDIUM	31

The remaining 1,863 problems are linked from individual company and topic pages.

The 1,923 problemsevery coding interview recycles.

The 1,923 problems
every coding interview recycles.