A collection of LeetCode questions to ace the coding interview! - Created using LeetHub v2

LeetCode Topics

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0013-roman-to-integer
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0020-valid-parentheses
0022-generate-parentheses
0032-longest-valid-parentheses
0049-group-anagrams
0058-length-of-last-word
0067-add-binary
0071-simplify-path
0072-edit-distance
0079-word-search
0091-decode-ways
0151-reverse-words-in-a-string
0168-excel-sheet-column-title
0205-isomorphic-strings
0242-valid-anagram
0290-word-pattern
0344-reverse-string
0345-reverse-vowels-of-a-string
0383-ransom-note
0392-is-subsequence
0567-permutation-in-string
0583-delete-operation-for-two-strings
0649-dota2-senate
0678-valid-parenthesis-string
0680-valid-palindrome-ii
0768-partition-labels
0778-reorganize-string
0990-verifying-an-alien-dictionary
1146-greatest-common-divisor-of-strings
1250-longest-common-subsequence
1304-longest-happy-string
1894-merge-strings-alternately
2001-jump-game-vii

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0032-longest-valid-parentheses
0042-trapping-rain-water
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0062-unique-paths
0063-unique-paths-ii
0064-minimum-path-sum
0070-climbing-stairs
0072-edit-distance
0091-decode-ways
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0152-maximum-product-subarray
0198-house-robber
0337-house-robber-iii
0338-counting-bits
0343-integer-break
0377-combination-sum-iv
0392-is-subsequence
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0494-target-sum
0518-coin-change-ii
0583-delete-operation-for-two-strings
0678-valid-parenthesis-string
0954-maximum-sum-circular-subarray
1020-longest-turbulent-subarray
1236-n-th-tribonacci-number
1250-longest-common-subsequence
2001-jump-game-vii

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0039-combination-sum
0046-permutations
0047-permutations-ii
0077-combinations
0078-subsets
0079-word-search
0494-target-sum
1993-sum-of-all-subset-xor-totals

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0036-valid-sudoku
0041-first-missing-positive
0049-group-anagrams
0073-set-matrix-zeroes
0128-longest-consecutive-sequence
0133-clone-graph
0141-linked-list-cycle
0146-lru-cache
0169-majority-element
0202-happy-number
0205-isomorphic-strings
0219-contains-duplicate-ii
0229-majority-element-ii
0242-valid-anagram
0290-word-pattern
0380-insert-delete-getrandom-o1
0383-ransom-note
0460-lfu-cache
0560-subarray-sum-equals-k
0567-permutation-in-string
0621-task-scheduler
0768-partition-labels
0778-reorganize-string
0816-design-hashset
0817-design-hashmap
0931-maximum-frequency-stack
0990-verifying-an-alien-dictionary
1039-find-the-town-judge
1392-find-the-difference-of-two-arrays
1798-max-number-of-k-sum-pairs

Array

0001-two-sum
0011-container-with-most-water
0015-3sum
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0036-valid-sudoku
0039-combination-sum
0041-first-missing-positive
0042-trapping-rain-water
0045-jump-game-ii
0046-permutations
0047-permutations-ii
0049-group-anagrams
0053-maximum-subarray
0055-jump-game
0056-merge-intervals
0063-unique-paths-ii
0064-minimum-path-sum
0066-plus-one
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0075-sort-colors
0078-subsets
0079-word-search
0080-remove-duplicates-from-sorted-array-ii
0081-search-in-rotated-sorted-array-ii
0084-largest-rectangle-in-histogram
0088-merge-sorted-array
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0128-longest-consecutive-sequence
0130-surrounded-regions
0134-gas-station
0136-single-number
0137-single-number-ii
0150-evaluate-reverse-polish-notation
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0189-rotate-array
0198-house-robber
0209-minimum-size-subarray-sum
0215-kth-largest-element-in-an-array
0219-contains-duplicate-ii
0229-majority-element-ii
0238-product-of-array-except-self
0239-sliding-window-maximum
0274-h-index
0283-move-zeroes
0287-find-the-duplicate-number
0304-range-sum-query-2d-immutable
0377-combination-sum-iv
0380-insert-delete-getrandom-o1
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0463-island-perimeter
0494-target-sum
0518-coin-change-ii
0560-subarray-sum-equals-k
0605-can-place-flowers
0621-task-scheduler
0658-find-k-closest-elements
0682-baseball-game
0724-find-pivot-index
0735-asteroid-collision
0739-daily-temperatures
0772-construct-quad-tree
0816-design-hashset
0817-design-hashmap
0860-design-circular-queue
0890-lemonade-change
0898-transpose-matrix
0907-koko-eating-bananas
0917-boats-to-save-people
0948-sort-an-array
0954-maximum-sum-circular-subarray
0990-verifying-an-alien-dictionary
1014-k-closest-points-to-origin
1020-longest-turbulent-subarray
1036-rotting-oranges
1039-find-the-town-judge
1127-last-stone-weight
1184-car-pooling
1185-find-in-mountain-array
1392-find-the-difference-of-two-arrays
1798-max-number-of-k-sum-pairs
1833-find-the-highest-altitude
1962-single-threaded-cpu
1993-sum-of-all-subset-xor-totals
2058-concatenation-of-array

Stack

0020-valid-parentheses
0032-longest-valid-parentheses
0042-trapping-rain-water
0071-simplify-path
0084-largest-rectangle-in-histogram
0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0150-evaluate-reverse-polish-notation
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0678-valid-parenthesis-string
0682-baseball-game
0735-asteroid-collision
0739-daily-temperatures
0931-maximum-frequency-stack

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0739-daily-temperatures

Divide and Conquer

0053-maximum-subarray
0169-majority-element
0190-reverse-bits
0215-kth-largest-element-in-an-array
0772-construct-quad-tree
0948-sort-an-array
0954-maximum-sum-circular-subarray
1014-k-closest-points-to-origin

Sorting

0015-3sum
0018-4sum
0047-permutations-ii
0049-group-anagrams
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0215-kth-largest-element-in-an-array
0229-majority-element-ii
0242-valid-anagram
0274-h-index
0435-non-overlapping-intervals
0621-task-scheduler
0658-find-k-closest-elements
0778-reorganize-string
0917-boats-to-save-people
0948-sort-an-array
1014-k-closest-points-to-origin
1184-car-pooling
1798-max-number-of-k-sum-pairs
1962-single-threaded-cpu

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0239-sliding-window-maximum
0621-task-scheduler
0658-find-k-closest-elements
0778-reorganize-string
0948-sort-an-array
1014-k-closest-points-to-origin
1127-last-stone-weight
1184-car-pooling
1304-longest-happy-string
1962-single-threaded-cpu

Quickselect

0215-kth-largest-element-in-an-array
1014-k-closest-points-to-origin

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0018-4sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0042-trapping-rain-water
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0141-linked-list-cycle
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0202-happy-number
0283-move-zeroes
0287-find-the-duplicate-number
0344-reverse-string
0345-reverse-vowels-of-a-string
0392-is-subsequence
0567-permutation-in-string
0658-find-k-closest-elements
0680-valid-palindrome-ii
0768-partition-labels
0917-boats-to-save-people
1798-max-number-of-k-sum-pairs
1894-merge-strings-alternately

Matrix

0036-valid-sudoku
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0079-word-search
0130-surrounded-regions
0304-range-sum-query-2d-immutable
0463-island-perimeter
0772-construct-quad-tree
0898-transpose-matrix
1036-rotting-oranges

Greedy

0011-container-with-most-water
0045-jump-game-ii
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0435-non-overlapping-intervals
0605-can-place-flowers
0621-task-scheduler
0649-dota2-senate
0678-valid-parenthesis-string
0680-valid-palindrome-ii
0768-partition-labels
0778-reorganize-string
0890-lemonade-change
0917-boats-to-save-people
1304-longest-happy-string

Bit Manipulation

0067-add-binary
0078-subsets
0136-single-number
0137-single-number-ii
0190-reverse-bits
0201-bitwise-and-of-numbers-range
0287-find-the-duplicate-number
0338-counting-bits
1441-minimum-flips-to-make-a-or-b-equal-to-c
1993-sum-of-all-subset-xor-totals
3394-minimum-array-end

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0239-sliding-window-maximum
0649-dota2-senate
0860-design-circular-queue
0954-maximum-sum-circular-subarray

Sliding Window

0003-longest-substring-without-repeating-characters
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0239-sliding-window-maximum
0567-permutation-in-string
0658-find-k-closest-elements
1020-longest-turbulent-subarray
2001-jump-game-vii

Monotonic Queue

0239-sliding-window-maximum
0954-maximum-sum-circular-subarray

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0092-reverse-linked-list-ii
0141-linked-list-cycle
0146-lru-cache
0206-reverse-linked-list
0460-lfu-cache
0816-design-hashset
0817-design-hashmap
0860-design-circular-queue

Design

0146-lru-cache
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0304-range-sum-query-2d-immutable
0380-insert-delete-getrandom-o1
0460-lfu-cache
0816-design-hashset
0817-design-hashmap
0860-design-circular-queue
0931-maximum-frequency-stack

Doubly-Linked List

0146-lru-cache
0460-lfu-cache

Merge Sort

0948-sort-an-array

Bucket Sort

0948-sort-an-array

Radix Sort

0948-sort-an-array

Counting Sort

0169-majority-element
0229-majority-element-ii
0274-h-index
0383-ransom-note
0621-task-scheduler
0778-reorganize-string
0948-sort-an-array

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0304-range-sum-query-2d-immutable
0560-subarray-sum-equals-k
0724-find-pivot-index
1184-car-pooling
1833-find-the-highest-altitude
2001-jump-game-vii

Math

0002-add-two-numbers
0009-palindrome-number
0013-roman-to-integer
0050-powx-n
0062-unique-paths
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0150-evaluate-reverse-polish-notation
0168-excel-sheet-column-title
0189-rotate-array
0202-happy-number
0343-integer-break
0380-insert-delete-getrandom-o1
1014-k-closest-points-to-origin
1146-greatest-common-divisor-of-strings
1236-n-th-tribonacci-number
1993-sum-of-all-subset-xor-totals

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0050-powx-n
0206-reverse-linked-list

Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0104-maximum-depth-of-binary-tree
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0230-kth-smallest-element-in-a-bst
0337-house-robber-iii
0450-delete-node-in-a-bst
0543-diameter-of-binary-tree
0772-construct-quad-tree
0784-insert-into-a-binary-search-tree
1450-delete-leaves-with-a-given-value

Depth-First Search

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0104-maximum-depth-of-binary-tree
0130-surrounded-regions
0133-clone-graph
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0207-course-schedule
0210-course-schedule-ii
0230-kth-smallest-element-in-a-bst
0337-house-robber-iii
0463-island-perimeter
0543-diameter-of-binary-tree
1450-delete-leaves-with-a-given-value

Breadth-First Search

0100-same-tree
0104-maximum-depth-of-binary-tree
0130-surrounded-regions
0133-clone-graph
0199-binary-tree-right-side-view
0207-course-schedule
0210-course-schedule-ii
0463-island-perimeter
1036-rotting-oranges

Binary Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0104-maximum-depth-of-binary-tree
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0230-kth-smallest-element-in-a-bst
0337-house-robber-iii
0450-delete-node-in-a-bst
0543-diameter-of-binary-tree
0784-insert-into-a-binary-search-tree
1450-delete-leaves-with-a-given-value

Memoization

0070-climbing-stairs
1236-n-th-tribonacci-number

Binary Search Tree

0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0069-sqrtx
0074-search-a-2d-matrix
0081-search-in-rotated-sorted-array-ii
0098-validate-binary-search-tree
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0230-kth-smallest-element-in-a-bst
0287-find-the-duplicate-number
0374-guess-number-higher-or-lower
0450-delete-node-in-a-bst
0658-find-k-closest-elements
0784-insert-into-a-binary-search-tree
0907-koko-eating-bananas
1185-find-in-mountain-array

Randomized

0380-insert-delete-getrandom-o1

Trie

0014-longest-common-prefix

Simulation

0067-add-binary
0682-baseball-game
0735-asteroid-collision
0898-transpose-matrix
1184-car-pooling
2058-concatenation-of-array

Database

0197-rising-temperature
0570-managers-with-at-least-5-direct-reports
0577-employee-bonus
0584-find-customer-referee
0595-big-countries
0620-not-boring-movies
1153-product-sales-analysis-i
1161-project-employees-i
1258-article-views-i
1317-monthly-transactions-i
1415-students-and-examinations
1509-replace-employee-id-with-the-unique-identifier
1724-customer-who-visited-but-did-not-make-any-transactions
1773-percentage-of-users-attended-a-contest
1801-average-time-of-process-per-machine
1908-recyclable-and-low-fat-products
2087-confirmation-rate

Graph

0133-clone-graph
0207-course-schedule
0210-course-schedule-ii
1039-find-the-town-judge

Union Find

0128-longest-consecutive-sequence
0130-surrounded-regions

Topological Sort

0207-course-schedule
0210-course-schedule-ii

Geometry

1014-k-closest-points-to-origin

Combinatorics

0062-unique-paths
1993-sum-of-all-subset-xor-totals

Interactive

0374-guess-number-higher-or-lower
1185-find-in-mountain-array

Enumeration

1993-sum-of-all-subset-xor-totals

Ordered Set

0931-maximum-frequency-stack

Hash Function

0816-design-hashset
0817-design-hashmap