LeetCode

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

LeetCode Topics

Database

0176-second-highest-salary
0180-consecutive-numbers
0185-department-top-three-salaries
0196-delete-duplicate-emails
0197-rising-temperature
0570-managers-with-at-least-5-direct-reports
0577-employee-bonus
0584-find-customer-referee
0585-investments-in-2016
0595-big-countries
0596-classes-more-than-5-students
0602-friend-requests-ii-who-has-the-most-friends
0610-triangle-judgement
0619-biggest-single-number
0620-not-boring-movies
0626-exchange-seats
1135-customers-who-bought-all-products
1153-product-sales-analysis-i
1155-product-sales-analysis-iii
1161-project-employees-i
1182-game-play-analysis-iv
1245-user-activity-for-the-past-30-days-i
1258-article-views-i
1278-product-price-at-a-given-date
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
1462-list-the-products-ordered-in-a-period
1480-movie-rating
1509-replace-employee-id-with-the-unique-identifier
1625-group-sold-products-by-the-date
1664-find-users-with-valid-e-mails
1670-patients-with-a-condition
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
1877-find-followers-count
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
2495-number-of-unique-subjects-taught-by-each-teacher

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
0015-3sum
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0045-jump-game-ii
0046-permutations
0048-rotate-image
0049-group-anagrams
0051-n-queens
0053-maximum-subarray
0054-spiral-matrix
0055-jump-game
0056-merge-intervals
0057-insert-interval
0063-unique-paths-ii
0064-minimum-path-sum
0066-plus-one
0068-text-justification
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0075-sort-colors
0078-subsets
0080-remove-duplicates-from-sorted-array-ii
0081-search-in-rotated-sorted-array-ii
0084-largest-rectangle-in-histogram
0088-merge-sorted-array
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0118-pascals-triangle
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0128-longest-consecutive-sequence
0130-surrounded-regions
0134-gas-station
0135-candy
0136-single-number
0137-single-number-ii
0139-word-break
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0179-largest-number
0188-best-time-to-buy-and-sell-stock-iv
0189-rotate-array
0198-house-robber
0204-count-primes
0209-minimum-size-subarray-sum
0212-word-search-ii
0213-house-robber-ii
0215-kth-largest-element-in-an-array
0216-combination-sum-iii
0217-contains-duplicate
0218-the-skyline-problem
0219-contains-duplicate-ii
0221-maximal-square
0228-summary-ranges
0238-product-of-array-except-self
0239-sliding-window-maximum
0240-search-a-2d-matrix-ii
0283-move-zeroes
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0312-burst-balloons
0322-coin-change
0330-patching-array
0347-top-k-frequent-elements
0368-largest-divisible-subset
0373-find-k-pairs-with-smallest-sums
0380-insert-delete-getrandom-o1
0399-evaluate-division
0407-trapping-rain-water-ii
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0436-find-right-interval
0442-find-all-duplicates-in-an-array
0452-minimum-number-of-arrows-to-burst-balloons
0494-target-sum
0518-coin-change-ii
0539-minimum-time-difference
0540-single-element-in-a-sorted-array
0542-01-matrix
0560-subarray-sum-equals-k
0605-can-place-flowers
0621-task-scheduler
0624-maximum-distance-in-arrays
0628-maximum-product-of-three-numbers
0632-smallest-range-covering-elements-from-k-lists
0643-maximum-average-subarray-i
0689-maximum-sum-of-3-non-overlapping-subarrays
0713-subarray-product-less-than-k
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0719-find-k-th-smallest-pair-distance
0721-accounts-merge
0724-find-pivot-index
0729-my-calendar-i
0731-my-calendar-ii
0735-asteroid-collision
0739-daily-temperatures
0745-find-smallest-letter-greater-than-target
0747-min-cost-climbing-stairs
0780-max-chunks-to-make-sorted
0787-sliding-puzzle
0792-binary-search
0854-making-a-large-island
0859-design-circular-deque
0870-magic-squares-in-grid
0890-lemonade-change
0892-shortest-subarray-with-sum-at-least-k
0906-walking-robot-simulation
0907-koko-eating-bananas
0921-spiral-matrix-iii
0943-sum-of-subarray-minimums
0945-snakes-and-ladders
0952-word-subsets
0954-maximum-sum-circular-subarray
0999-regions-cut-by-slashes
1002-maximum-width-ramp
1016-subarray-sums-divisible-by-k
1025-minimum-cost-for-tickets
1034-subarrays-with-k-different-integers
1036-rotting-oranges
1046-max-consecutive-ones-iii
1063-best-sightseeing-pair
1137-height-checker
1145-number-of-submatrices-that-sum-to-target
1147-flip-columns-for-maximum-number-of-equal-rows
1240-stone-game-ii
1256-rank-transform-of-an-array
1319-unique-number-of-occurrences
1325-path-with-maximum-probability
1350-remove-sub-folders-from-the-filesystem
1392-find-the-difference-of-two-arrays
1396-count-servers-that-communicate
1397-search-suggestions-system
1402-count-square-submatrices-with-all-ones
1435-xor-queries-of-a-subarray
1468-check-if-n-and-its-double-exist
1476-count-negative-numbers-in-a-sorted-matrix
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1497-design-a-stack-with-increment-operation
1524-string-matching-in-an-array
1528-kids-with-the-greatest-number-of-candies
1556-make-two-arrays-equal-by-reversing-subarrays
1570-final-prices-with-a-special-discount-in-a-shop
1586-longest-subarray-of-1s-after-deleting-one-element
1615-range-sum-of-sorted-subarray-sums
1620-check-if-array-pairs-are-divisible-by-k
1663-detect-cycles-in-2d-grid
1677-matrix-diagonal-sum
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1691-minimum-number-of-days-to-disconnect-island
1694-make-sum-divisible-by-p
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1755-defuse-the-bomb
1766-minimum-number-of-removals-to-make-mountain-array
1786-count-the-number-of-consistent-strings
1798-max-number-of-k-sum-pairs
1833-find-the-highest-altitude
1876-map-of-highest-peak
1878-check-if-array-is-sorted-and-rotated
1886-minimum-limit-of-balls-in-a-bag
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1917-maximum-average-pass-ratio
1923-sentence-similarity-iii
1951-find-the-winner-of-the-circular-game
1966-frequency-of-the-most-frequent-element
1972-rotating-the-box
2006-find-the-student-that-will-replace-the-chalk
2035-count-sub-islands
2038-nearest-exit-from-entrance-in-maze
2054-the-number-of-the-smallest-unoccupied-chair
2067-maximum-number-of-points-with-cost
2089-maximum-matrix-sum
2132-convert-1d-array-into-2d-array
2145-grid-game
2155-find-missing-observations
2163-kth-distinct-string-in-an-array
2164-two-best-non-overlapping-events
2170-count-number-of-maximum-bitwise-or-subsets
2188-minimized-maximum-of-products-distributed-to-any-store
2232-adding-spaces-to-a-string
2255-minimum-swaps-to-group-all-1s-together-ii
2292-counting-words-with-a-given-prefix
2343-count-unguarded-cells-in-the-grid
2358-number-of-ways-to-split-array
2375-minimum-obstacle-removal-to-reach-corner
2392-successful-pairs-of-spells-and-potions
2411-spiral-matrix-iv
2428-equal-row-and-column-pairs
2465-shifting-letters-ii
2488-divide-intervals-into-minimum-number-of-groups
2494-sum-of-prefix-scores-of-strings
2503-longest-subarray-with-maximum-bitwise-and
2533-bitwise-xor-of-all-pairings
2545-height-of-binary-tree-after-subtree-removal-queries
2552-maximum-sum-of-distinct-subarrays-with-length-k
2553-total-cost-to-hire-k-workers
2554-minimum-total-distance-traveled
2581-divide-players-into-teams-of-equal-skill
2625-increment-submatrices-by-one
2636-maximum-subsequence-score
2640-maximum-number-of-integers-to-choose-from-a-range-i
2685-first-completely-painted-row-or-column
2691-count-vowel-strings-in-ranges
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
2699-count-the-number-of-fair-pairs
2716-prime-subtraction-operation
2727-number-of-senior-citizens
2755-extra-characters-in-a-string
2764-maximum-number-of-fish-in-a-grid
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
2794-maximum-number-of-moves-in-a-grid
2868-continuous-subarrays
2891-maximum-beauty-of-an-array-after-applying-operation
3219-make-lexicographically-smallest-array-by-swapping-elements
3291-find-if-array-can-be-sorted
3309-count-prefix-and-suffix-pairs-i
3329-find-the-length-of-the-longest-common-prefix
3334-apple-redistribution-into-boxes
3427-special-array-ii
3429-special-array-i
3501-delete-nodes-from-linked-list-present-in-array
3517-shortest-distance-after-road-addition-queries-i
3522-find-the-power-of-k-size-subarrays-i
3555-final-array-state-after-k-multiplication-operations-i

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0028-find-the-index-of-the-first-occurrence-in-a-string
0031-next-permutation
0061-rotate-list
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0082-remove-duplicates-from-sorted-list-ii
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0202-happy-number
0234-palindrome-linked-list
0283-move-zeroes
0287-find-the-duplicate-number
0295-find-median-from-data-stream
0344-reverse-string
0345-reverse-vowels-of-a-string
0392-is-subsequence
0443-string-compression
0567-permutation-in-string
0680-valid-palindrome-ii
0719-find-k-th-smallest-pair-distance
0908-middle-of-the-linked-list
1468-check-if-n-and-its-double-exist
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1615-range-sum-of-sorted-subarray-sums
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1798-max-number-of-k-sum-pairs
1894-merge-strings-alternately
1923-sentence-similarity-iii
1972-rotating-the-box
2095-minimum-number-of-swaps-to-make-the-string-balanced
2216-delete-the-middle-node-of-a-linked-list
2232-adding-spaces-to-a-string
2236-maximum-twin-sum-of-a-linked-list
2392-successful-pairs-of-spells-and-potions
2414-move-pieces-to-obtain-a-string
2488-divide-intervals-into-minimum-number-of-groups
2553-total-cost-to-hire-k-workers
2581-divide-players-into-teams-of-equal-skill
2699-count-the-number-of-fair-pairs
3018-make-string-a-subsequence-using-cyclic-increments
3195-separate-black-and-white-balls

Sorting

0015-3sum
0049-group-anagrams
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0148-sort-list
0169-majority-element
0179-largest-number
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0242-valid-anagram
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0368-largest-divisible-subset
0435-non-overlapping-intervals
0436-find-right-interval
0452-minimum-number-of-arrows-to-burst-balloons
0539-minimum-time-difference
0621-task-scheduler
0628-maximum-product-of-three-numbers
0632-smallest-range-covering-elements-from-k-lists
0719-find-k-th-smallest-pair-distance
0721-accounts-merge
0780-max-chunks-to-make-sorted
1029-vertical-order-traversal-of-a-binary-tree
1137-height-checker
1256-rank-transform-of-an-array
1397-search-suggestions-system
1468-check-if-n-and-its-double-exist
1556-make-two-arrays-equal-by-reversing-subarrays
1615-range-sum-of-sorted-subarray-sums
1777-determine-if-two-strings-are-close
1798-max-number-of-k-sum-pairs
1966-frequency-of-the-most-frequent-element
2164-two-best-non-overlapping-events
2392-successful-pairs-of-spells-and-potions
2488-divide-intervals-into-minimum-number-of-groups
2554-minimum-total-distance-traveled
2581-divide-players-into-teams-of-equal-skill
2636-maximum-subsequence-score
2640-maximum-number-of-integers-to-choose-from-a-range-i
2695-find-score-of-an-array-after-marking-all-elements
2699-count-the-number-of-fair-pairs
2891-maximum-beauty-of-an-array-after-applying-operation
3219-make-lexicographically-smallest-array-by-swapping-elements
3276-minimum-number-of-pushes-to-type-word-ii
3291-find-if-array-can-be-sorted
3334-apple-redistribution-into-boxes

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0239-sliding-window-maximum
0438-find-all-anagrams-in-a-string
0567-permutation-in-string
0632-smallest-range-covering-elements-from-k-lists
0643-maximum-average-subarray-i
0713-subarray-product-less-than-k
0892-shortest-subarray-with-sum-at-least-k
1034-subarrays-with-k-different-integers
1046-max-consecutive-ones-iii
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1586-longest-subarray-of-1s-after-deleting-one-element
1755-defuse-the-bomb
1966-frequency-of-the-most-frequent-element
2255-minimum-swaps-to-group-all-1s-together-ii
2275-find-substring-with-given-hash-value
2552-maximum-sum-of-distinct-subarrays-with-length-k
2599-take-k-of-each-character-from-left-and-right
2868-continuous-subarrays
2891-maximum-beauty-of-an-array-after-applying-operation
3522-find-the-power-of-k-size-subarrays-i

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0048-rotate-image
0050-powx-n
0062-unique-paths
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0089-gray-code
0096-unique-binary-search-trees
0168-excel-sheet-column-title
0172-factorial-trailing-zeroes
0189-rotate-array
0202-happy-number
0204-count-primes
0224-basic-calculator
0241-different-ways-to-add-parentheses
0264-ugly-number-ii
0273-integer-to-english-words
0279-perfect-squares
0368-largest-divisible-subset
0380-insert-delete-getrandom-o1
0441-arranging-coins
0539-minimum-time-difference
0564-find-the-closest-palindrome
0592-fraction-addition-and-subtraction
0628-maximum-product-of-three-numbers
0650-2-keys-keyboard
0668-kth-smallest-number-in-multiplication-table
0670-maximum-swap
0870-magic-squares-in-grid
1146-greatest-common-divisor-of-strings
1236-n-th-tribonacci-number
1240-stone-game-ii
1411-convert-binary-number-in-a-linked-list-to-integer
1951-find-the-winner-of-the-circular-game
2032-largest-odd-number-in-string
2155-find-missing-observations
2716-prime-subtraction-operation
2903-insert-greatest-common-divisors-in-linked-list
3555-final-array-state-after-k-multiplication-operations-i

Binary Search

0004-median-of-two-sorted-arrays
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
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0222-count-complete-tree-nodes
0240-search-a-2d-matrix-ii
0278-first-bad-version
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0374-guess-number-higher-or-lower
0436-find-right-interval
0441-arranging-coins
0540-single-element-in-a-sorted-array
0668-kth-smallest-number-in-multiplication-table
0713-subarray-product-less-than-k
0719-find-k-th-smallest-pair-distance
0729-my-calendar-i
0731-my-calendar-ii
0745-find-smallest-letter-greater-than-target
0792-binary-search
0892-shortest-subarray-with-sum-at-least-k
0907-koko-eating-bananas
1046-max-consecutive-ones-iii
1397-search-suggestions-system
1468-check-if-n-and-its-double-exist
1476-count-negative-numbers-in-a-sorted-matrix
1615-range-sum-of-sorted-subarray-sums
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1766-minimum-number-of-removals-to-make-mountain-array
1886-minimum-limit-of-balls-in-a-bag
1966-frequency-of-the-most-frequent-element
2006-find-the-student-that-will-replace-the-chalk
2164-two-best-non-overlapping-events
2188-minimized-maximum-of-products-distributed-to-any-store
2392-successful-pairs-of-spells-and-potions
2640-maximum-number-of-integers-to-choose-from-a-range-i
2699-count-the-number-of-fair-pairs
2716-prime-subtraction-operation
2891-maximum-beauty-of-an-array-after-applying-operation
3427-special-array-ii

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0560-subarray-sum-equals-k
0713-subarray-product-less-than-k
0724-find-pivot-index
0731-my-calendar-ii
0892-shortest-subarray-with-sum-at-least-k
1016-subarray-sums-divisible-by-k
1046-max-consecutive-ones-iii
1145-number-of-submatrices-that-sum-to-target
1240-stone-game-ii
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1537-maximum-score-after-splitting-a-string
1694-make-sum-divisible-by-p
1833-find-the-highest-altitude
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1966-frequency-of-the-most-frequent-element
2006-find-the-student-that-will-replace-the-chalk
2059-unique-length-3-palindromic-subsequences
2145-grid-game
2358-number-of-ways-to-split-array
2465-shifting-letters-ii
2488-divide-intervals-into-minimum-number-of-groups
2625-increment-submatrices-by-one
2691-count-vowel-strings-in-ranges
3427-special-array-ii

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0037-sudoku-solver
0049-group-anagrams
0073-set-matrix-zeroes
0076-minimum-window-substring
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0128-longest-consecutive-sequence
0133-clone-graph
0138-copy-list-with-random-pointer
0139-word-break
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0160-intersection-of-two-linked-lists
0169-majority-element
0202-happy-number
0208-implement-trie-prefix-tree
0217-contains-duplicate
0219-contains-duplicate-ii
0242-valid-anagram
0264-ugly-number-ii
0290-word-pattern
0347-top-k-frequent-elements
0380-insert-delete-getrandom-o1
0383-ransom-note
0409-longest-palindrome
0432-all-oone-data-structure
0433-minimum-genetic-mutation
0438-find-all-anagrams-in-a-string
0442-find-all-duplicates-in-an-array
0460-lfu-cache
0560-subarray-sum-equals-k
0567-permutation-in-string
0621-task-scheduler
0632-smallest-range-covering-elements-from-k-lists
0721-accounts-merge
0870-magic-squares-in-grid
0906-walking-robot-simulation
0920-uncommon-words-from-two-sentences
0931-maximum-frequency-stack
0952-word-subsets
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
1016-subarray-sums-divisible-by-k
1029-vertical-order-traversal-of-a-binary-tree
1034-subarrays-with-k-different-integers
1145-number-of-submatrices-that-sum-to-target
1147-flip-columns-for-maximum-number-of-equal-rows
1256-rank-transform-of-an-array
1297-maximum-number-of-balloons
1319-unique-number-of-occurrences
1392-find-the-difference-of-two-arrays
1468-check-if-n-and-its-double-exist
1473-find-the-longest-substring-containing-vowels-in-even-counts
1502-construct-k-palindrome-strings
1556-make-two-arrays-equal-by-reversing-subarrays
1620-check-if-array-pairs-are-divisible-by-k
1668-find-longest-awesome-substring
1694-make-sum-divisible-by-p
1777-determine-if-two-strings-are-close
1786-count-the-number-of-consistent-strings
1798-max-number-of-k-sum-pairs
2054-the-number-of-the-smallest-unoccupied-chair
2059-unique-length-3-palindromic-subsequences
2163-kth-distinct-string-in-an-array
2300-construct-string-with-repeat-limit
2413-smallest-number-in-infinite-set
2428-equal-row-and-column-pairs
2552-maximum-sum-of-distinct-subarrays-with-length-k
2581-divide-players-into-teams-of-equal-skill
2599-take-k-of-each-character-from-left-and-right
2640-maximum-number-of-integers-to-choose-from-a-range-i
2677-cousins-in-binary-tree-ii
2685-first-completely-painted-row-or-column
2695-find-score-of-an-array-after-marking-all-elements
2755-extra-characters-in-a-string
2766-find-the-prefix-common-array-of-two-arrays
3276-minimum-number-of-pushes-to-type-word-ii
3329-find-the-length-of-the-longest-common-prefix
3408-count-the-number-of-special-characters-i
3455-minimum-length-of-string-after-operations
3501-delete-nodes-from-linked-list-present-in-array

Counting Sort

0169-majority-element
0347-top-k-frequent-elements
0383-ransom-note
0621-task-scheduler
0920-uncommon-words-from-two-sentences
1034-subarrays-with-k-different-integers
1137-height-checker
1297-maximum-number-of-balloons
1396-count-servers-that-communicate
1502-construct-k-palindrome-strings
1620-check-if-array-pairs-are-divisible-by-k
1777-determine-if-two-strings-are-close
1786-count-the-number-of-consistent-strings
2163-kth-distinct-string-in-an-array
2300-construct-string-with-repeat-limit
2494-sum-of-prefix-scores-of-strings
3276-minimum-number-of-pushes-to-type-word-ii
3455-minimum-length-of-string-after-operations

Divide and Conquer

0004-median-of-two-sorted-arrays
0023-merge-k-sorted-lists
0053-maximum-subarray
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0148-sort-list
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits
0215-kth-largest-element-in-an-array
0218-the-skyline-problem
0240-search-a-2d-matrix-ii
0347-top-k-frequent-elements
0954-maximum-sum-circular-subarray

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0032-longest-valid-parentheses
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
0096-unique-binary-search-trees
0118-pascals-triangle
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0139-word-break
0152-maximum-product-subarray
0188-best-time-to-buy-and-sell-stock-iv
0198-house-robber
0213-house-robber-ii
0221-maximal-square
0241-different-ways-to-add-parentheses
0264-ugly-number-ii
0279-perfect-squares
0300-longest-increasing-subsequence
0312-burst-balloons
0322-coin-change
0338-counting-bits
0368-largest-divisible-subset
0392-is-subsequence
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0494-target-sum
0518-coin-change-ii
0542-01-matrix
0650-2-keys-keyboard
0664-strange-printer
0689-maximum-sum-of-3-non-overlapping-subarrays
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0747-min-cost-climbing-stairs
0806-domino-and-tromino-tiling
0863-sum-of-distances-in-tree
0943-sum-of-subarray-minimums
0954-maximum-sum-circular-subarray
1025-minimum-cost-for-tickets
1063-best-sightseeing-pair
1236-n-th-tribonacci-number
1240-stone-game-ii
1250-longest-common-subsequence
1402-count-square-submatrices-with-all-ones
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1586-longest-subarray-of-1s-after-deleting-one-element
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1766-minimum-number-of-removals-to-make-mountain-array
2067-maximum-number-of-points-with-cost
2164-two-best-non-overlapping-events
2554-minimum-total-distance-traveled
2562-count-ways-to-build-good-strings
2755-extra-characters-in-a-string
2794-maximum-number-of-moves-in-a-grid

Bit Manipulation

0067-add-binary
0078-subsets
0089-gray-code
0136-single-number
0137-single-number-ii
0190-reverse-bits
0191-number-of-1-bits
0201-bitwise-and-of-numbers-range
0222-count-complete-tree-nodes
0287-find-the-duplicate-number
0338-counting-bits
0476-number-complement
1435-xor-queries-of-a-subarray
1441-minimum-flips-to-make-a-or-b-equal-to-c
1473-find-the-longest-substring-containing-vowels-in-even-counts
1668-find-longest-awesome-substring
1786-count-the-number-of-consistent-strings
2059-unique-length-3-palindromic-subsequences
2170-count-number-of-maximum-bitwise-or-subsets
2323-minimum-bit-flips-to-convert-number
2503-longest-subarray-with-maximum-bitwise-and
2509-minimize-xor
2533-bitwise-xor-of-all-pairings
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
3291-find-if-array-can-be-sorted
3394-minimum-array-end

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
0135-candy
0179-largest-number
0330-patching-array
0409-longest-palindrome
0435-non-overlapping-intervals
0452-minimum-number-of-arrows-to-burst-balloons
0605-can-place-flowers
0621-task-scheduler
0624-maximum-distance-in-arrays
0632-smallest-range-covering-elements-from-k-lists
0649-dota2-senate
0670-maximum-swap
0680-valid-palindrome-ii
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0780-max-chunks-to-make-sorted
0890-lemonade-change
0957-minimum-add-to-make-parentheses-valid
1304-longest-happy-string
1502-construct-k-palindrome-strings
1766-minimum-number-of-removals-to-make-mountain-array
1917-maximum-average-pass-ratio
1966-frequency-of-the-most-frequent-element
2032-largest-odd-number-in-string
2089-maximum-matrix-sum
2095-minimum-number-of-swaps-to-make-the-string-balanced
2221-check-if-a-parentheses-string-can-be-valid
2300-construct-string-with-repeat-limit
2488-divide-intervals-into-minimum-number-of-groups
2509-minimize-xor
2636-maximum-subsequence-score
2640-maximum-number-of-integers-to-choose-from-a-range-i
2716-prime-subtraction-operation
3195-separate-black-and-white-balls
3276-minimum-number-of-pushes-to-type-word-ii
3334-apple-redistribution-into-boxes

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0006-zigzag-conversion
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0020-valid-parentheses
0022-generate-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0032-longest-valid-parentheses
0049-group-anagrams
0058-length-of-last-word
0065-valid-number
0067-add-binary
0068-text-justification
0072-edit-distance
0076-minimum-window-substring
0125-valid-palindrome
0139-word-break
0151-reverse-words-in-a-string
0168-excel-sheet-column-title
0179-largest-number
0208-implement-trie-prefix-tree
0212-word-search-ii
0214-shortest-palindrome
0224-basic-calculator
0241-different-ways-to-add-parentheses
0242-valid-anagram
0273-integer-to-english-words
0290-word-pattern
0344-reverse-string
0345-reverse-vowels-of-a-string
0383-ransom-note
0392-is-subsequence
0394-decode-string
0399-evaluate-division
0409-longest-palindrome
0433-minimum-genetic-mutation
0438-find-all-anagrams-in-a-string
0443-string-compression
0539-minimum-time-difference
0564-find-the-closest-palindrome
0567-permutation-in-string
0592-fraction-addition-and-subtraction
0649-dota2-senate
0664-strange-printer
0680-valid-palindrome-ii
0721-accounts-merge
0812-rotate-string
0920-uncommon-words-from-two-sentences
0952-word-subsets
0957-minimum-add-to-make-parentheses-valid
1146-greatest-common-divisor-of-strings
1197-parsing-a-boolean-expression
1250-longest-common-subsequence
1297-maximum-number-of-balloons
1302-delete-characters-to-make-fancy-string
1304-longest-happy-string
1350-remove-sub-folders-from-the-filesystem
1397-search-suggestions-system
1473-find-the-longest-substring-containing-vowels-in-even-counts
1502-construct-k-palindrome-strings
1524-string-matching-in-an-array
1537-maximum-score-after-splitting-a-string
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1668-find-longest-awesome-substring
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1777-determine-if-two-strings-are-close
1786-count-the-number-of-consistent-strings
1894-merge-strings-alternately
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1923-sentence-similarity-iii
2032-largest-odd-number-in-string
2059-unique-length-3-palindromic-subsequences
2076-sum-of-digits-of-string-after-convert
2095-minimum-number-of-swaps-to-make-the-string-balanced
2163-kth-distinct-string-in-an-array
2221-check-if-a-parentheses-string-can-be-valid
2232-adding-spaces-to-a-string
2275-find-substring-with-given-hash-value
2292-counting-words-with-a-given-prefix
2300-construct-string-with-repeat-limit
2414-move-pieces-to-obtain-a-string
2465-shifting-letters-ii
2470-removing-stars-from-a-string
2494-sum-of-prefix-scores-of-strings
2580-circular-sentence
2599-take-k-of-each-character-from-left-and-right
2691-count-vowel-strings-in-ranges
2727-number-of-senior-citizens
2755-extra-characters-in-a-string
2800-minimum-string-length-after-removing-substrings
3018-make-string-a-subsequence-using-cyclic-increments
3174-minimum-number-of-changes-to-make-binary-string-beautiful
3195-separate-black-and-white-balls
3276-minimum-number-of-pushes-to-type-word-ii
3309-count-prefix-and-suffix-pairs-i
3329-find-the-length-of-the-longest-common-prefix
3408-count-the-number-of-special-characters-i
3451-string-compression-iii
3455-minimum-length-of-string-after-operations

Trie

0014-longest-common-prefix
0139-word-break
0208-implement-trie-prefix-tree
0212-word-search-ii
0386-lexicographical-numbers
0440-k-th-smallest-in-lexicographical-order
1350-remove-sub-folders-from-the-filesystem
1397-search-suggestions-system
2494-sum-of-prefix-scores-of-strings
2755-extra-characters-in-a-string
3309-count-prefix-and-suffix-pairs-i
3329-find-the-length-of-the-longest-common-prefix

Interactive

0278-first-bad-version
0374-guess-number-higher-or-lower

Matrix

0037-sudoku-solver
0048-rotate-image
0054-spiral-matrix
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0130-surrounded-regions
0212-word-search-ii
0221-maximal-square
0240-search-a-2d-matrix-ii
0407-trapping-rain-water-ii
0542-01-matrix
0787-sliding-puzzle
0854-making-a-large-island
0870-magic-squares-in-grid
0921-spiral-matrix-iii
0945-snakes-and-ladders
0999-regions-cut-by-slashes
1036-rotting-oranges
1145-number-of-submatrices-that-sum-to-target
1147-flip-columns-for-maximum-number-of-equal-rows
1396-count-servers-that-communicate
1402-count-square-submatrices-with-all-ones
1476-count-negative-numbers-in-a-sorted-matrix
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1663-detect-cycles-in-2d-grid
1677-matrix-diagonal-sum
1691-minimum-number-of-days-to-disconnect-island
1876-map-of-highest-peak
1972-rotating-the-box
2035-count-sub-islands
2038-nearest-exit-from-entrance-in-maze
2089-maximum-matrix-sum
2132-convert-1d-array-into-2d-array
2145-grid-game
2343-count-unguarded-cells-in-the-grid
2375-minimum-obstacle-removal-to-reach-corner
2411-spiral-matrix-iv
2428-equal-row-and-column-pairs
2625-increment-submatrices-by-one
2685-first-completely-painted-row-or-column
2764-maximum-number-of-fish-in-a-grid
2794-maximum-number-of-moves-in-a-grid

Simulation

0054-spiral-matrix
0067-add-binary
0068-text-justification
0592-fraction-addition-and-subtraction
0735-asteroid-collision
0906-walking-robot-simulation
0921-spiral-matrix-iii
1951-find-the-winner-of-the-circular-game
2006-find-the-student-that-will-replace-the-chalk
2076-sum-of-digits-of-string-after-convert
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2232-adding-spaces-to-a-string
2343-count-unguarded-cells-in-the-grid
2411-spiral-matrix-iv
2428-equal-row-and-column-pairs
2470-removing-stars-from-a-string
2553-total-cost-to-hire-k-workers
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
2800-minimum-string-length-after-removing-substrings
3555-final-array-state-after-k-multiplication-operations-i

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
0214-shortest-palindrome
0812-rotate-string
1524-string-matching-in-an-array
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group
0061-rotate-list
0082-remove-duplicates-from-sorted-list-ii
0083-remove-duplicates-from-sorted-list
0092-reverse-linked-list-ii
0117-populating-next-right-pointers-in-each-node-ii
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0148-sort-list
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0234-palindrome-linked-list
0328-odd-even-linked-list
0432-all-oone-data-structure
0460-lfu-cache
0725-split-linked-list-in-parts
0859-design-circular-deque
0908-middle-of-the-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer
1484-linked-list-in-binary-tree
2216-delete-the-middle-node-of-a-linked-list
2236-maximum-twin-sum-of-a-linked-list
2411-spiral-matrix-iv
2903-insert-greatest-common-divisors-in-linked-list
3501-delete-nodes-from-linked-list-present-in-array

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group
0050-powx-n
0206-reverse-linked-list
0224-basic-calculator
0234-palindrome-linked-list
0241-different-ways-to-add-parentheses
0273-integer-to-english-words
0394-decode-string
1197-parsing-a-boolean-expression
1951-find-the-winner-of-the-circular-game

Stack

0020-valid-parentheses
0032-longest-valid-parentheses
0084-largest-rectangle-in-histogram
0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0155-min-stack
0173-binary-search-tree-iterator
0224-basic-calculator
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0394-decode-string
0735-asteroid-collision
0739-daily-temperatures
0776-n-ary-tree-postorder-traversal
0780-max-chunks-to-make-sorted
0931-maximum-frequency-stack
0937-online-stock-span
0943-sum-of-subarray-minimums
0957-minimum-add-to-make-parentheses-valid
1002-maximum-width-ramp
1197-parsing-a-boolean-expression
1497-design-a-stack-with-increment-operation
1570-final-prices-with-a-special-discount-in-a-shop
1679-shortest-subarray-to-be-removed-to-make-array-sorted
2095-minimum-number-of-swaps-to-make-the-string-balanced
2221-check-if-a-parentheses-string-can-be-valid
2236-maximum-twin-sum-of-a-linked-list
2470-removing-stars-from-a-string
2800-minimum-string-length-after-removing-substrings

Design

0146-lru-cache
0155-min-stack
0173-binary-search-tree-iterator
0208-implement-trie-prefix-tree
0232-implement-queue-using-stacks
0295-find-median-from-data-stream
0380-insert-delete-getrandom-o1
0432-all-oone-data-structure
0460-lfu-cache
0729-my-calendar-i
0731-my-calendar-ii
0789-kth-largest-element-in-a-stream
0859-design-circular-deque
0931-maximum-frequency-stack
0937-online-stock-span
0969-number-of-recent-calls
1497-design-a-stack-with-increment-operation
2413-smallest-number-in-infinite-set

Ordered Set

0218-the-skyline-problem
0729-my-calendar-i
0731-my-calendar-ii
0931-maximum-frequency-stack
2868-continuous-subarrays

Queue

0232-implement-queue-using-stacks
0239-sliding-window-maximum
0649-dota2-senate
0859-design-circular-deque
0892-shortest-subarray-with-sum-at-least-k
0954-maximum-sum-circular-subarray
0969-number-of-recent-calls
1951-find-the-winner-of-the-circular-game
2868-continuous-subarrays

Monotonic Queue

0239-sliding-window-maximum
0892-shortest-subarray-with-sum-at-least-k
0954-maximum-sum-circular-subarray
2868-continuous-subarrays

Depth-First Search

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0100-same-tree
0104-maximum-depth-of-binary-tree
0112-path-sum
0117-populating-next-right-pointers-in-each-node-ii
0129-sum-root-to-leaf-numbers
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
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0386-lexicographical-numbers
0399-evaluate-division
0437-path-sum-iii
0515-find-largest-value-in-each-tree-row
0547-number-of-provinces
0617-merge-two-binary-trees
0684-redundant-connection
0721-accounts-merge
0776-n-ary-tree-postorder-traversal
0799-minimum-distance-between-bst-nodes
0801-is-graph-bipartite
0820-find-eventual-safe-states
0854-making-a-large-island
0863-sum-of-distances-in-tree
0904-leaf-similar-trees
0984-most-stones-removed-with-same-row-or-column
0988-flip-equivalent-binary-trees
0999-regions-cut-by-slashes
1029-vertical-order-traversal-of-a-binary-tree
1116-maximum-level-sum-of-a-binary-tree
1350-remove-sub-folders-from-the-filesystem
1396-count-servers-that-communicate
1484-linked-list-in-binary-tree
1544-count-good-nodes-in-binary-tree
1558-course-schedule-iv
1576-reorder-routes-to-make-all-paths-lead-to-the-city-zero
1663-detect-cycles-in-2d-grid
1691-minimum-number-of-days-to-disconnect-island
2035-count-sub-islands
2201-valid-arrangement-of-pairs
2246-maximum-employees-to-be-invited-to-a-meeting
2493-reverse-odd-levels-of-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2677-cousins-in-binary-tree-ii
2764-maximum-number-of-fish-in-a-grid
3058-maximum-number-of-k-divisible-components
3439-find-minimum-diameter-after-merging-two-trees

Breadth-First Search

0100-same-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0112-path-sum
0117-populating-next-right-pointers-in-each-node-ii
0130-surrounded-regions
0133-clone-graph
0199-binary-tree-right-side-view
0207-course-schedule
0226-invert-binary-tree
0279-perfect-squares
0322-coin-change
0399-evaluate-division
0407-trapping-rain-water-ii
0433-minimum-genetic-mutation
0515-find-largest-value-in-each-tree-row
0542-01-matrix
0547-number-of-provinces
0617-merge-two-binary-trees
0684-redundant-connection
0721-accounts-merge
0787-sliding-puzzle
0799-minimum-distance-between-bst-nodes
0801-is-graph-bipartite
0820-find-eventual-safe-states
0854-making-a-large-island
0945-snakes-and-ladders
0999-regions-cut-by-slashes
1029-vertical-order-traversal-of-a-binary-tree
1036-rotting-oranges
1116-maximum-level-sum-of-a-binary-tree
1396-count-servers-that-communicate
1484-linked-list-in-binary-tree
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1544-count-good-nodes-in-binary-tree
1558-course-schedule-iv
1576-reorder-routes-to-make-all-paths-lead-to-the-city-zero
1663-detect-cycles-in-2d-grid
1691-minimum-number-of-days-to-disconnect-island
1876-map-of-highest-peak
2035-count-sub-islands
2038-nearest-exit-from-entrance-in-maze
2375-minimum-obstacle-removal-to-reach-corner
2493-reverse-odd-levels-of-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2583-divide-nodes-into-the-maximum-number-of-groups
2677-cousins-in-binary-tree-ii
2764-maximum-number-of-fish-in-a-grid
3439-find-minimum-diameter-after-merging-two-trees
3517-shortest-distance-after-road-addition-queries-i

Union Find

0128-longest-consecutive-sequence
0130-surrounded-regions
0399-evaluate-division
0547-number-of-provinces
0684-redundant-connection
0721-accounts-merge
0801-is-graph-bipartite
0854-making-a-large-island
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
1396-count-servers-that-communicate
1663-detect-cycles-in-2d-grid
2035-count-sub-islands
2583-divide-nodes-into-the-maximum-number-of-groups
2764-maximum-number-of-fish-in-a-grid
3219-make-lexicographically-smallest-array-by-swapping-elements

Data Stream

0295-find-median-from-data-stream
0789-kth-largest-element-in-a-stream
0937-online-stock-span
0969-number-of-recent-calls

Strongly Connected Component

1691-minimum-number-of-days-to-disconnect-island

Tree

0094-binary-tree-inorder-traversal
0096-unique-binary-search-trees
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0100-same-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0112-path-sum
0117-populating-next-right-pointers-in-each-node-ii
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0437-path-sum-iii
0450-delete-node-in-a-bst
0515-find-largest-value-in-each-tree-row
0617-merge-two-binary-trees
0776-n-ary-tree-postorder-traversal
0783-search-in-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0799-minimum-distance-between-bst-nodes
0863-sum-of-distances-in-tree
0904-leaf-similar-trees
0988-flip-equivalent-binary-trees
1029-vertical-order-traversal-of-a-binary-tree
1116-maximum-level-sum-of-a-binary-tree
1484-linked-list-in-binary-tree
1544-count-good-nodes-in-binary-tree
2493-reverse-odd-levels-of-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2677-cousins-in-binary-tree-ii
3058-maximum-number-of-k-divisible-components
3439-find-minimum-diameter-after-merging-two-trees

Binary Search Tree

0096-unique-binary-search-trees
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0108-convert-sorted-array-to-binary-search-tree
0173-binary-search-tree-iterator
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0450-delete-node-in-a-bst
0783-search-in-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0799-minimum-distance-between-bst-nodes

Heap (Priority Queue)

0023-merge-k-sorted-lists
0215-kth-largest-element-in-an-array
0218-the-skyline-problem
0239-sliding-window-maximum
0264-ugly-number-ii
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0373-find-k-pairs-with-smallest-sums
0407-trapping-rain-water-ii
0621-task-scheduler
0632-smallest-range-covering-elements-from-k-lists
0789-kth-largest-element-in-a-stream
0892-shortest-subarray-with-sum-at-least-k
1304-longest-happy-string
1325-path-with-maximum-probability
1397-search-suggestions-system
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1917-maximum-average-pass-ratio
2054-the-number-of-the-smallest-unoccupied-chair
2164-two-best-non-overlapping-events
2300-construct-string-with-repeat-limit
2375-minimum-obstacle-removal-to-reach-corner
2413-smallest-number-in-infinite-set
2488-divide-intervals-into-minimum-number-of-groups
2553-total-cost-to-hire-k-workers
2636-maximum-subsequence-score
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
2803-modify-graph-edge-weights
2868-continuous-subarrays
3555-final-array-state-after-k-multiplication-operations-i

Binary Tree

0094-binary-tree-inorder-traversal
0096-unique-binary-search-trees
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0100-same-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0112-path-sum
0117-populating-next-right-pointers-in-each-node-ii
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0437-path-sum-iii
0450-delete-node-in-a-bst
0515-find-largest-value-in-each-tree-row
0617-merge-two-binary-trees
0783-search-in-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0799-minimum-distance-between-bst-nodes
0904-leaf-similar-trees
0988-flip-equivalent-binary-trees
1029-vertical-order-traversal-of-a-binary-tree
1116-maximum-level-sum-of-a-binary-tree
1484-linked-list-in-binary-tree
1544-count-good-nodes-in-binary-tree
2493-reverse-odd-levels-of-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2677-cousins-in-binary-tree-ii

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0051-n-queens
0052-n-queens-ii
0078-subsets
0089-gray-code
0212-word-search-ii
0216-combination-sum-iii
0494-target-sum
2170-count-number-of-maximum-bitwise-or-subsets

Doubly-Linked List

0146-lru-cache
0432-all-oone-data-structure
0460-lfu-cache

Quickselect

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements

Merge Sort

0023-merge-k-sorted-lists
0148-sort-list

Game Theory

1240-stone-game-ii

Monotonic Stack

0084-largest-rectangle-in-histogram
0739-daily-temperatures
0780-max-chunks-to-make-sorted
0937-online-stock-span
0943-sum-of-subarray-minimums
1002-maximum-width-ramp
1570-final-prices-with-a-special-discount-in-a-shop
1679-shortest-subarray-to-be-removed-to-make-array-sorted

Graph

0133-clone-graph
0207-course-schedule
0399-evaluate-division
0547-number-of-provinces
0684-redundant-connection
0801-is-graph-bipartite
0820-find-eventual-safe-states
0863-sum-of-distances-in-tree
0984-most-stones-removed-with-same-row-or-column
1325-path-with-maximum-probability
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1558-course-schedule-iv
1576-reorder-routes-to-make-all-paths-lead-to-the-city-zero
2201-valid-arrangement-of-pairs
2246-maximum-employees-to-be-invited-to-a-meeting
2375-minimum-obstacle-removal-to-reach-corner
2583-divide-nodes-into-the-maximum-number-of-groups
2803-modify-graph-edge-weights
3189-find-champion-ii
3439-find-minimum-diameter-after-merging-two-trees
3517-shortest-distance-after-road-addition-queries-i

Shortest Path

0399-evaluate-division
1325-path-with-maximum-probability
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2375-minimum-obstacle-removal-to-reach-corner
2803-modify-graph-edge-weights

Number Theory

0204-count-primes
2716-prime-subtraction-operation
2903-insert-greatest-common-divisors-in-linked-list

Memoization

0070-climbing-stairs
0139-word-break
0241-different-ways-to-add-parentheses
1236-n-th-tribonacci-number

Brainteaser

2503-longest-subarray-with-maximum-bitwise-and
2533-bitwise-xor-of-all-pairings

Combinatorics

0062-unique-paths

Rolling Hash

0214-shortest-palindrome
2275-find-substring-with-given-hash-value
3309-count-prefix-and-suffix-pairs-i

Hash Function

0214-shortest-palindrome
2275-find-substring-with-given-hash-value
3309-count-prefix-and-suffix-pairs-i

Segment Tree

0218-the-skyline-problem
0729-my-calendar-i
0731-my-calendar-ii

Enumeration

0204-count-primes
2170-count-number-of-maximum-bitwise-or-subsets

Randomized

0380-insert-delete-getrandom-o1

Topological Sort

0207-course-schedule
0820-find-eventual-safe-states
1558-course-schedule-iv
2246-maximum-employees-to-be-invited-to-a-meeting

Bucket Sort

0347-top-k-frequent-elements

Iterator

0173-binary-search-tree-iterator

Eulerian Circuit

2201-valid-arrangement-of-pairs

Binary Indexed Tree

0218-the-skyline-problem

Line Sweep

0218-the-skyline-problem