Leetcode

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

LeetCode Topics

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0042-trapping-rain-water
0118-pascals-triangle
0119-pascals-triangle-ii
0123-best-time-to-buy-and-sell-stock-iii
0139-word-break
0140-word-break-ii
0221-maximal-square
0233-number-of-digit-one
0300-longest-increasing-subsequence
0312-burst-balloons
0329-longest-increasing-path-in-a-matrix
0403-frog-jump
0464-can-i-win
0472-concatenated-words
0518-coin-change-ii
0542-01-matrix
0691-stickers-to-spell-word
0698-partition-to-k-equal-sum-subsets
0803-cheapest-flights-within-k-stops
0863-sum-of-distances-in-tree
0877-shortest-path-visiting-all-nodes
1038-number-of-squareful-arrays
1121-partition-array-for-maximum-sum
1348-maximum-score-of-spliced-array
1352-maximum-profit-in-job-scheduling
1402-count-square-submatrices-with-all-ones
1457-minimum-difficulty-of-a-job-schedule
1669-minimum-cost-to-cut-a-stick
2028-the-earliest-and-latest-rounds-where-players-compete
2114-minimum-number-of-work-sessions-to-finish-the-tasks
2397-count-number-of-ways-to-place-houses
2504-find-all-good-indices
2882-ways-to-express-an-integer-as-sum-of-powers
3491-find-the-maximum-length-of-valid-subsequence-ii
3648-find-the-maximum-number-of-fruits-collected
3795-zero-array-transformation-iv
3801-count-beautiful-numbers
3831-find-x-value-of-array-i

Bit Manipulation

0029-divide-two-integers
0078-subsets
0231-power-of-two
0342-power-of-four
0464-can-i-win
0691-stickers-to-spell-word
0698-partition-to-k-equal-sum-subsets
0877-shortest-path-visiting-all-nodes
1038-number-of-squareful-arrays
2114-minimum-number-of-work-sessions-to-finish-the-tasks
2170-count-number-of-maximum-bitwise-or-subsets
2400-minimum-score-after-removals-on-a-tree
2498-smallest-subarrays-with-maximum-bitwise-or
2529-range-product-queries-of-powers
2837-minimum-operations-to-make-the-integer-zero
3601-find-the-k-th-character-in-string-game-ii

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0127-word-ladder
0130-surrounded-regions
0199-binary-tree-right-side-view
0207-course-schedule
0210-course-schedule-ii
0297-serialize-and-deserialize-binary-tree
0310-minimum-height-trees
0329-longest-increasing-path-in-a-matrix
0542-01-matrix
0547-number-of-provinces
0662-maximum-width-of-binary-tree
0684-redundant-connection
0721-accounts-merge
0794-swim-in-rising-water
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0854-making-a-large-island
0877-shortest-path-visiting-all-nodes
0893-all-nodes-distance-k-in-binary-tree
0922-possible-bipartition
0960-minimize-malware-spread
1029-vertical-order-traversal-of-a-binary-tree
1036-rotting-oranges
1073-number-of-enclaves
1171-shortest-path-in-binary-matrix
1308-smallest-string-with-swaps
1414-shortest-path-in-a-grid-with-obstacles-elimination
1424-maximum-candies-you-can-get-from-boxes
2403-count-unreachable-pairs-of-nodes-in-an-undirected-graph

Graph

0207-course-schedule
0210-course-schedule-ii
0310-minimum-height-trees
0329-longest-increasing-path-in-a-matrix
0332-reconstruct-itinerary
0547-number-of-provinces
0684-redundant-connection
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0863-sum-of-distances-in-tree
0877-shortest-path-visiting-all-nodes
0881-loud-and-rich
0922-possible-bipartition
0960-minimize-malware-spread
1424-maximum-candies-you-can-get-from-boxes
2403-count-unreachable-pairs-of-nodes-in-an-undirected-graph
2505-number-of-good-paths

Bitmask

0464-can-i-win
0691-stickers-to-spell-word
0698-partition-to-k-equal-sum-subsets
0877-shortest-path-visiting-all-nodes
1038-number-of-squareful-arrays
2114-minimum-number-of-work-sessions-to-finish-the-tasks

Array

0015-3sum
0016-3sum-closest
0026-remove-duplicates-from-sorted-array
0033-search-in-rotated-sorted-array
0036-valid-sudoku
0037-sudoku-solver
0041-first-missing-positive
0042-trapping-rain-water
0049-group-anagrams
0056-merge-intervals
0074-search-a-2d-matrix
0078-subsets
0084-largest-rectangle-in-histogram
0088-merge-sorted-array
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0118-pascals-triangle
0119-pascals-triangle-ii
0123-best-time-to-buy-and-sell-stock-iii
0128-longest-consecutive-sequence
0130-surrounded-regions
0139-word-break
0140-word-break-ii
0154-find-minimum-in-rotated-sorted-array-ii
0215-kth-largest-element-in-an-array
0221-maximal-square
0239-sliding-window-maximum
0300-longest-increasing-subsequence
0312-burst-balloons
0329-longest-increasing-path-in-a-matrix
0403-frog-jump
0454-4sum-ii
0472-concatenated-words
0485-max-consecutive-ones
0496-next-greater-element-i
0503-next-greater-element-ii
0518-coin-change-ii
0542-01-matrix
0560-subarray-sum-equals-k
0679-24-game
0691-stickers-to-spell-word
0698-partition-to-k-equal-sum-subsets
0721-accounts-merge
0731-my-calendar-ii
0735-asteroid-collision
0794-swim-in-rising-water
0853-most-profit-assigning-work
0854-making-a-large-island
0881-loud-and-rich
0883-car-fleet
0907-koko-eating-bananas
0940-fruit-into-baskets
0959-3sum-with-multiplicity
0960-minimize-malware-spread
0966-binary-subarrays-with-sum
1034-subarrays-with-k-different-integers
1036-rotting-oranges
1038-number-of-squareful-arrays
1046-max-consecutive-ones-iii
1073-number-of-enclaves
1121-partition-array-for-maximum-sum
1171-shortest-path-in-binary-matrix
1184-car-pooling
1308-smallest-string-with-swaps
1348-maximum-score-of-spliced-array
1352-maximum-profit-in-job-scheduling
1370-count-number-of-nice-subarrays
1402-count-square-submatrices-with-all-ones
1414-shortest-path-in-a-grid-with-obstacles-elimination
1424-maximum-candies-you-can-get-from-boxes
1457-minimum-difficulty-of-a-job-schedule
1538-maximum-points-you-can-obtain-from-cards
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1605-minimum-number-of-days-to-make-m-bouquets
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1669-minimum-cost-to-cut-a-stick
1813-maximum-erasure-value
1918-maximum-score-of-a-good-subarray
1977-minimum-interval-to-include-each-query
1983-maximum-population-year
2114-minimum-number-of-work-sessions-to-finish-the-tasks
2170-count-number-of-maximum-bitwise-or-subsets
2227-sum-of-subarray-ranges
2229-maximum-fruits-harvested-after-at-most-k-steps
2316-count-hills-and-valleys-in-an-array
2320-find-all-k-distant-indices-in-an-array
2387-partition-array-such-that-maximum-difference-is-k
2400-minimum-score-after-removals-on-a-tree
2432-number-of-zero-filled-subarrays
2498-smallest-subarrays-with-maximum-bitwise-or
2504-find-all-good-indices
2505-number-of-good-paths
2529-range-product-queries-of-powers
2689-rearranging-fruits
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3648-find-the-maximum-number-of-fruits-collected
3750-closest-equal-element-queries
3788-maximum-unique-subarray-sum-after-deletion
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii
3795-zero-array-transformation-iv
3831-find-x-value-of-array-i
3886-count-number-of-trapezoids-i

Math

0029-divide-two-integers
0231-power-of-two
0233-number-of-digit-one
0326-power-of-three
0342-power-of-four
0464-can-i-win
0679-24-game
1038-number-of-squareful-arrays
1370-count-number-of-nice-subarrays
1411-convert-binary-number-in-a-linked-list-to-integer
1448-maximum-69-number
2432-number-of-zero-filled-subarrays
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3601-find-the-k-th-character-in-string-game-ii
3754-maximum-manhattan-distance-after-k-changes
3830-find-closest-person
3831-find-x-value-of-array-i
3886-count-number-of-trapezoids-i

Matrix

0036-valid-sudoku
0037-sudoku-solver
0074-search-a-2d-matrix
0130-surrounded-regions
0221-maximal-square
0329-longest-increasing-path-in-a-matrix
0542-01-matrix
0794-swim-in-rising-water
0854-making-a-large-island
1036-rotting-oranges
1073-number-of-enclaves
1171-shortest-path-in-binary-matrix
1402-count-square-submatrices-with-all-ones
1414-shortest-path-in-a-grid-with-obstacles-elimination
3648-find-the-maximum-number-of-fruits-collected

Hash Table

0003-longest-substring-without-repeating-characters
0036-valid-sudoku
0037-sudoku-solver
0041-first-missing-positive
0049-group-anagrams
0076-minimum-window-substring
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0127-word-ladder
0128-longest-consecutive-sequence
0139-word-break
0140-word-break-ii
0141-linked-list-cycle
0142-linked-list-cycle-ii
0424-longest-repeating-character-replacement
0454-4sum-ii
0496-next-greater-element-i
0560-subarray-sum-equals-k
0691-stickers-to-spell-word
0721-accounts-merge
0893-all-nodes-distance-k-in-binary-tree
0940-fruit-into-baskets
0959-3sum-with-multiplicity
0960-minimize-malware-spread
0966-binary-subarrays-with-sum
1029-vertical-order-traversal-of-a-binary-tree
1034-subarrays-with-k-different-integers
1038-number-of-squareful-arrays
1308-smallest-string-with-swaps
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1813-maximum-erasure-value
2505-number-of-good-paths
2689-rearranging-fruits
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3750-closest-equal-element-queries
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes
3788-maximum-unique-subarray-sum-after-deletion
3886-count-number-of-trapezoids-i

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0020-valid-parentheses
0022-generate-parentheses
0049-group-anagrams
0076-minimum-window-substring
0127-word-ladder
0139-word-break
0140-word-break-ii
0297-serialize-and-deserialize-binary-tree
0316-remove-duplicate-letters
0402-remove-k-digits
0424-longest-repeating-character-replacement
0472-concatenated-words
0680-valid-palindrome-ii
0691-stickers-to-spell-word
0721-accounts-merge
1058-lexicographically-smallest-equivalent-string
1159-smallest-subsequence-of-distinct-characters
1308-smallest-string-with-swaps
1371-minimum-remove-to-make-valid-parentheses
1460-number-of-substrings-containing-all-three-characters
1818-maximum-score-from-removing-substrings
2346-largest-3-same-digit-number-in-string
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3683-find-the-lexicographically-largest-string-from-the-box-i
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes

Trie

0139-word-break
0140-word-break-ii
0472-concatenated-words

Memoization

0139-word-break
0140-word-break-ii
0329-longest-increasing-path-in-a-matrix
0464-can-i-win
0691-stickers-to-spell-word
0698-partition-to-k-equal-sum-subsets
2028-the-earliest-and-latest-rounds-where-players-compete

Two Pointers

0005-longest-palindromic-substring
0015-3sum
0016-3sum-closest
0026-remove-duplicates-from-sorted-array
0042-trapping-rain-water
0061-rotate-list
0088-merge-sorted-array
0141-linked-list-cycle
0142-linked-list-cycle-ii
0234-palindrome-linked-list
0680-valid-palindrome-ii
0853-most-profit-assigning-work
0959-3sum-with-multiplicity
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1918-maximum-score-of-a-good-subarray
2320-find-all-k-distant-indices-in-an-array
3683-find-the-lexicographically-largest-string-from-the-box-i

Enumeration

2170-count-number-of-maximum-bitwise-or-subsets
2837-minimum-operations-to-make-the-integer-zero
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3683-find-the-lexicographically-largest-string-from-the-box-i

Union Find

0128-longest-consecutive-sequence
0130-surrounded-regions
0547-number-of-provinces
0684-redundant-connection
0721-accounts-merge
0794-swim-in-rising-water
0801-is-graph-bipartite
0854-making-a-large-island
0922-possible-bipartition
0960-minimize-malware-spread
1058-lexicographically-smallest-equivalent-string
1073-number-of-enclaves
1308-smallest-string-with-swaps
2403-count-unreachable-pairs-of-nodes-in-an-undirected-graph
2505-number-of-good-paths

Stack

0020-valid-parentheses
0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0094-binary-tree-inorder-traversal
0155-min-stack
0234-palindrome-linked-list
0316-remove-duplicate-letters
0402-remove-k-digits
0496-next-greater-element-i
0503-next-greater-element-ii
0735-asteroid-collision
0883-car-fleet
1159-smallest-subsequence-of-distinct-characters
1371-minimum-remove-to-make-valid-parentheses
1818-maximum-score-from-removing-substrings
1918-maximum-score-of-a-good-subarray
2227-sum-of-subarray-ranges
3445-lexicographically-minimum-string-after-removing-stars

Greedy

0316-remove-duplicate-letters
0402-remove-k-digits
0680-valid-palindrome-ii
0853-most-profit-assigning-work
1159-smallest-subsequence-of-distinct-characters
1448-maximum-69-number
1818-maximum-score-from-removing-substrings
2387-partition-array-such-that-maximum-difference-is-k
2689-rearranging-fruits
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3788-maximum-unique-subarray-sum-after-deletion

Heap (Priority Queue)

0023-merge-k-sorted-lists
0215-kth-largest-element-in-an-array
0239-sliding-window-maximum
0794-swim-in-rising-water
0803-cheapest-flights-within-k-stops
1184-car-pooling
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1977-minimum-interval-to-include-each-query
3445-lexicographically-minimum-string-after-removing-stars

Counting

0959-3sum-with-multiplicity
1034-subarrays-with-k-different-integers
1983-maximum-population-year
3360-minimum-deletions-to-make-string-k-special
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes

Linked List

0023-merge-k-sorted-lists
0025-reverse-nodes-in-k-group
0061-rotate-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0234-palindrome-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer

Recursion

0025-reverse-nodes-in-k-group
0231-power-of-two
0233-number-of-digit-one
0234-palindrome-linked-list
0326-power-of-three
0342-power-of-four
3601-find-the-k-th-character-in-string-game-ii

Database

0175-combine-two-tables
0176-second-highest-salary
0181-employees-earning-more-than-their-managers
0182-duplicate-emails
0183-customers-who-never-order
0196-delete-duplicate-emails
0197-rising-temperature
0570-managers-with-at-least-5-direct-reports
0577-employee-bonus
0584-find-customer-referee
0586-customer-placing-the-largest-number-of-orders
0595-big-countries
0602-friend-requests-ii-who-has-the-most-friends
0610-triangle-judgement
0620-not-boring-movies
0626-exchange-seats
1155-product-sales-analysis-iii
1179-game-play-analysis-i
1258-article-views-i
1292-immediate-food-delivery-ii
1317-monthly-transactions-i
1327-last-person-to-fit-in-the-bus
1338-queries-quality-and-percentage
1390-average-selling-price
1415-students-and-examinations
1480-movie-rating
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
1811-fix-names-in-a-table
1827-invalid-tweets
1882-the-number-of-employees-which-report-to-each-employee
1908-recyclable-and-low-fat-products
1942-primary-department-for-each-employee
2057-count-salary-categories
2087-confirmation-rate
2127-employees-whose-manager-left-the-company

Depth-First Search

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0130-surrounded-regions
0199-binary-tree-right-side-view
0207-course-schedule
0210-course-schedule-ii
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0310-minimum-height-trees
0329-longest-increasing-path-in-a-matrix
0332-reconstruct-itinerary
0472-concatenated-words
0543-diameter-of-binary-tree
0547-number-of-provinces
0662-maximum-width-of-binary-tree
0684-redundant-connection
0721-accounts-merge
0794-swim-in-rising-water
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0854-making-a-large-island
0863-sum-of-distances-in-tree
0881-loud-and-rich
0893-all-nodes-distance-k-in-binary-tree
0922-possible-bipartition
0960-minimize-malware-spread
1029-vertical-order-traversal-of-a-binary-tree
1073-number-of-enclaves
1308-smallest-string-with-swaps
2400-minimum-score-after-removals-on-a-tree
2403-count-unreachable-pairs-of-nodes-in-an-undirected-graph

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0316-remove-duplicate-letters
0402-remove-k-digits
0496-next-greater-element-i
0503-next-greater-element-ii
0883-car-fleet
1159-smallest-subsequence-of-distinct-characters
1918-maximum-score-of-a-good-subarray
2227-sum-of-subarray-ranges

Binary Search

0033-search-in-rotated-sorted-array
0074-search-a-2d-matrix
0154-find-minimum-in-rotated-sorted-array-ii
0300-longest-increasing-subsequence
0731-my-calendar-ii
0732-my-calendar-iii
0794-swim-in-rising-water
0853-most-profit-assigning-work
0907-koko-eating-bananas
1046-max-consecutive-ones-iii
1352-maximum-profit-in-job-scheduling
1605-minimum-number-of-days-to-make-m-bouquets
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1918-maximum-score-of-a-good-subarray
1977-minimum-interval-to-include-each-query
2229-maximum-fruits-harvested-after-at-most-k-steps
2498-smallest-subarrays-with-maximum-bitwise-or
3750-closest-equal-element-queries
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Sorting

0015-3sum
0016-3sum-closest
0049-group-anagrams
0056-merge-intervals
0088-merge-sorted-array
0215-kth-largest-element-in-an-array
0721-accounts-merge
0853-most-profit-assigning-work
0883-car-fleet
0959-3sum-with-multiplicity
1029-vertical-order-traversal-of-a-binary-tree
1184-car-pooling
1308-smallest-string-with-swaps
1352-maximum-profit-in-job-scheduling
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1669-minimum-cost-to-cut-a-stick
1977-minimum-interval-to-include-each-query
2387-partition-array-such-that-maximum-difference-is-k
2505-number-of-good-paths
2689-rearranging-fruits
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3360-minimum-deletions-to-make-string-k-special

Design

0155-min-stack
0297-serialize-and-deserialize-binary-tree
0731-my-calendar-ii
0732-my-calendar-iii

Simulation

0735-asteroid-collision
1184-car-pooling
3790-fruits-into-baskets-ii

Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0199-binary-tree-right-side-view
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0450-delete-node-in-a-bst
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0784-insert-into-a-binary-search-tree
0863-sum-of-distances-in-tree
0893-all-nodes-distance-k-in-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
2400-minimum-score-after-removals-on-a-tree
2505-number-of-good-paths

Game Theory

0464-can-i-win

Queue

0239-sliding-window-maximum
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0239-sliding-window-maximum
0424-longest-repeating-character-replacement
0940-fruit-into-baskets
0966-binary-subarrays-with-sum
1034-subarrays-with-k-different-integers
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1538-maximum-points-you-can-obtain-from-cards
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1813-maximum-erasure-value
2229-maximum-fruits-harvested-after-at-most-k-steps
2498-smallest-subarrays-with-maximum-bitwise-or

Monotonic Queue

0239-sliding-window-maximum
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Prefix Sum

0560-subarray-sum-equals-k
0731-my-calendar-ii
0732-my-calendar-iii
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1184-car-pooling
1370-count-number-of-nice-subarrays
1538-maximum-points-you-can-obtain-from-cards
1983-maximum-population-year
2229-maximum-fruits-harvested-after-at-most-k-steps
2504-find-all-good-indices
2529-range-product-queries-of-powers

Topological Sort

0207-course-schedule
0210-course-schedule-ii
0310-minimum-height-trees
0329-longest-increasing-path-in-a-matrix
0881-loud-and-rich

Geometry

3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3886-count-number-of-trapezoids-i

Backtracking

0022-generate-parentheses
0037-sudoku-solver
0078-subsets
0140-word-break-ii
0679-24-game
0691-stickers-to-spell-word
0698-partition-to-k-equal-sum-subsets
1038-number-of-squareful-arrays
2114-minimum-number-of-work-sessions-to-finish-the-tasks
2170-count-number-of-maximum-bitwise-or-subsets

Divide and Conquer

0023-merge-k-sorted-lists
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0215-kth-largest-element-in-an-array

Merge Sort

0023-merge-k-sorted-lists

Line Sweep

1977-minimum-interval-to-include-each-query

Segment Tree

0731-my-calendar-ii
0732-my-calendar-iii
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Ordered Set

0731-my-calendar-ii
0732-my-calendar-iii
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Shortest Path

0803-cheapest-flights-within-k-stops

Binary Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0199-binary-tree-right-side-view
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0450-delete-node-in-a-bst
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0784-insert-into-a-binary-search-tree
0893-all-nodes-distance-k-in-binary-tree
1029-vertical-order-traversal-of-a-binary-tree

Binary Search Tree

0098-validate-binary-search-tree
0230-kth-smallest-element-in-a-bst
0450-delete-node-in-a-bst
0784-insert-into-a-binary-search-tree

Quickselect

0215-kth-largest-element-in-an-array

Eulerian Circuit

0332-reconstruct-itinerary

Brainteaser

2837-minimum-operations-to-make-the-integer-zero