Leetcode problem list

TopSWE 100

Solve these 100 carefully curated problems in order. See you at the top!

Asked at MAANG

and other top 50 tech companies

Checkbox	Number	ID	Title	Tags
Checkbox	1	412	easyfizz buzz	math string simulation
Checkbox	2	1	easytwo sum	array hash table
Checkbox	3	242	easyvalid anagram	string sorting hash table
Checkbox	4	344	easyreverse string	string two pointers
Checkbox	5	125	easyvalid palindrome	string two pointers
Checkbox	6	14	easylongest common prefix	trie string
Checkbox	7	326	easypower of three	math recursion
Checkbox	8	191	easynumber of 1 bits	bit manipulation divide and conquer
Checkbox	9	303	easyrange sum query - immutable	array design prefix sum
Checkbox	10	1013	easyfibonacci number	math recursion memoization +1
Checkbox	11	70	easyclimbing stairs	math memoization dynamic programming
Checkbox	12	747	easymin cost climbing stairs	array dynamic programming
Checkbox	13	121	easybest time to buy and sell stock	array dynamic programming
Checkbox	14	94	easybinary tree inorder traversal	tree stack binary tree +1
Checkbox	15	226	easyinvert binary tree	tree binary tree depth first search +1
Checkbox	16	101	easysymmetric tree	tree binary tree depth first search +1
Checkbox	17	104	easymaximum depth of binary tree	tree binary tree depth first search +1
Checkbox	18	100	easysame tree	tree binary tree depth first search +1
Checkbox	19	112	easypath sum	tree binary tree depth first search +1
Checkbox	20	111	easyminimum depth of binary tree	tree binary tree depth first search +1
Checkbox	21	98	mediumvalidate binary search tree	tree binary tree depth first search +1
Checkbox	22	206	easyreverse linked list	recursion linked list
Checkbox	23	908	easymiddle of the linked list	linked list two pointers
Checkbox	24	102	mediumbinary tree level order traversal	tree binary tree breadth first search
Checkbox	25	2121	easyfind if path exists in graph	graph union find depth first search +1
Checkbox	26	200	mediumnumber of islands	array matrix union find +2
Checkbox	27	695	mediummax area of island	array matrix union find +2
Checkbox	28	2035	mediumcount sub islands	array matrix union find +2
Checkbox	29	20	easyvalid parentheses	stack string
Checkbox	30	238	mediumproduct of array except self	array prefix sum
Checkbox	31	792	easybinary search	array binary search
Checkbox	32	957	mediumminimum add to make parentheses valid	stack string greedy
Checkbox	33	5	mediumlongest palindromic substring	string dynamic programming
Checkbox	34	167	mediumtwo sum ii - input array is sorted	array two pointers binary search
Checkbox	35	11	mediumcontainer with most water	array greedy two pointers
Checkbox	36	15	medium3sum	array sorting two pointers
Checkbox	37	49	mediumgroup anagrams	array string sorting +1
Checkbox	38	215	mediumkth largest element in an array	array sorting quickselect +2
Checkbox	39	1014	mediumk closest points to origin	math array sorting +4
Checkbox	40	380	mediuminsert delete getrandom o(1)	math array design +2
Checkbox	41	278	easyfirst bad version	interactive binary search
Checkbox	42	162	mediumfind peak element	array binary search
Checkbox	43	69	easysqrt(x)	math binary search
Checkbox	44	907	mediumkoko eating bananas	array binary search
Checkbox	45	560	mediumsubarray sum equals k	array hash table prefix sum
Checkbox	46	523	mediumcontinuous subarray sum	math array hash table +1
Checkbox	47	1370	mediumcount number of nice subarrays	math array hash table +1
Checkbox	48	133	mediumclone graph	graph hash table depth first search +1
Checkbox	49	138	mediumcopy list with random pointer	hash table linked list
Checkbox	50	801	mediumis graph bipartite?	graph union find depth first search +1
Checkbox	51	399	mediumevaluate division	array graph union find +3
Checkbox	52	53	mediummaximum subarray	array divide and conquer dynamic programming
Checkbox	53	152	mediummaximum product subarray	array dynamic programming
Checkbox	54	62	mediumunique paths	math combinatorics dynamic programming
Checkbox	55	64	mediumminimum path sum	array matrix dynamic programming
Checkbox	56	3	mediumlongest substring without repeating characters	string hash table sliding window
Checkbox	57	1046	mediummax consecutive ones iii	array prefix sum binary search +1
Checkbox	58	2134	mediummaximize the confusion of an exam	string prefix sum binary search +1
Checkbox	59	2478	mediumlongest nice subarray	array sliding window bit manipulation
Checkbox	60	912	mediumrandom pick with weight	math array prefix sum +2
Checkbox	61	139	mediumword break	trie array string +3
Checkbox	62	198	mediumhouse robber	array dynamic programming
Checkbox	63	322	mediumcoin change	array dynamic programming breadth first search
Checkbox	64	300	mediumlongest increasing subsequence	array binary search dynamic programming
Checkbox	65	1250	mediumlongest common subsequence	string dynamic programming
Checkbox	66	235	mediumlowest common ancestor of a binary search tree	tree binary tree depth first search +1
Checkbox	67	124	hardbinary tree maximum path sum	tree binary tree depth first search +1
Checkbox	68	122	mediumbest time to buy and sell stock ii	array greedy dynamic programming
Checkbox	69	55	mediumjump game	array greedy dynamic programming
Checkbox	70	210	mediumcourse schedule ii	graph topological sort depth first search +1
Checkbox	71	1325	mediumpath with maximum probability	array graph shortest path +1
Checkbox	72	1753	mediumpath with minimum effort	array matrix union find +4
Checkbox	73	56	mediummerge intervals	array sorting
Checkbox	74	57	mediuminsert interval	array
Checkbox	75	1028	mediuminterval list intersections	array two pointers
Checkbox	76	146	mediumlru cache	design hash table linked list +1
Checkbox	77	173	mediumbinary search tree iterator	tree stack design +3
Checkbox	78	155	mediummin stack	stack design
Checkbox	79	225	easyimplement stack using queues	stack queue design
Checkbox	80	17	mediumletter combinations of a phone number	string hash table backtracking
Checkbox	81	39	mediumcombination sum	array backtracking
Checkbox	82	46	mediumpermutations	array backtracking
Checkbox	83	78	mediumsubsets	array backtracking bit manipulation
Checkbox	84	131	mediumpalindrome partitioning	string backtracking dynamic programming
Checkbox	85	208	mediumimplement trie (prefix tree)	trie string design +1
Checkbox	86	224	hardbasic calculator	math stack string +1
Checkbox	87	739	mediumdaily temperatures	array stack monotonic stack
Checkbox	88	937	mediumonline stock span	stack design data stream +1
Checkbox	89	416	mediumpartition equal subset sum	array dynamic programming
Checkbox	90	684	mediumredundant connection	graph union find depth first search +1
Checkbox	91	295	hardfind median from data stream	design sorting data stream +2
Checkbox	92	42	hardtrapping rain water	array stack two pointers +2
Checkbox	93	149	hardmax points on a line	math array geometry +1
Checkbox	94	297	hardserialize and deserialize binary tree	tree string design +3
Checkbox	95	1352	hardmaximum profit in job scheduling	array sorting binary search +1
Checkbox	96	239	hardsliding window maximum	array queue sliding window +2
Checkbox	97	72	mediumedit distance	string dynamic programming
Checkbox	98	84	hardlargest rectangle in histogram	array stack monotonic stack
Checkbox	99	726	hardnumber of atoms	stack string sorting +1
Checkbox	100	460	hardlfu cache	design hash table linked list +1
			Congratulations!