LeetCode Solutions Summary

Total Problems Solved: 65

List of Problems Solved:

• 40-combination-sum-ii
• 0048-rotate-image
• 0053-maximum-subarray
• 0056-merge-intervals
• 0118-pascals-triangle
• 145-binary-tree-postorder-traversal
• 0197-rising-temperature
• 215-kth-largest-element-in-an-array
• 241-different-ways-to-add-parentheses
• 264-ugly-number-ii
• 273-integer-to-english-words
• 295-find-median-from-data-stream
• 347-top-k-frequent-elements
• 415-add-strings
• 455-assign-cookies
• 0496-next-greater-element-i
• 564-find-the-closest-palindrome
• 0584-find-customer-referee
• 592-fraction-addition-and-subtraction
• 0595-big-countries
• 624-maximum-distance-in-arrays
• 650-2-keys-keyboard
• 664-strange-printer
• 719-find-k-th-smallest-pair-distance
• 725-split-linked-list-in-parts
• 0729-my-calendar-i
• 776-n-ary-tree-postorder-traversal
• 0812-rotate-string
• 890-lemonade-change
• 906-walking-robot-simulation
• 984-most-stones-removed-with-same-row-or-column
• 1153-product-sales-analysis-i
• 1197-parsing-a-boolean-expression
• 1240-stone-game-ii
• 1258-article-views-i
• 1325-path-with-maximum-probability
• 1484-linked-list-in-binary-tree
• 1509-replace-employee-id-with-the-unique-identifier
• 1556-make-two-arrays-equal-by-reversing-subarrays
• 1615-range-sum-of-sorted-subarray-sums
• 1724-customer-who-visited-but-did-not-make-any-transactions
• 1827-invalid-tweets
• 1908-recyclable-and-low-fat-products
• 2006-find-the-student-that-will-replace-the-chalk
• 2035-count-sub-islands
• 2067-maximum-number-of-points-with-cost
• 2089-maximum-matrix-sum
• 2132-convert-1d-array-into-2d-array
• 2155-find-missing-observations
• 2163-kth-distinct-string-in-an-array
• 2179-most-beautiful-item-for-each-query
• 2180-maximum-number-of-tasks-you-can-assign
• 2248-minimum-cost-of-buying-candies-with-discount
• 2343-count-unguarded-cells-in-the-grid
• 2411-spiral-matrix-iv
• 2503-longest-subarray-with-maximum-bitwise-and
• 2552-maximum-sum-of-distinct-subarrays-with-length-k
• 2599-take-k-of-each-character-from-left-and-right
• 2677-cousins-in-binary-tree-ii
• 2803-modify-graph-edge-weights
• 2903-insert-greatest-common-divisors-in-linked-list
• 3174-minimum-number-of-changes-to-make-binary-string-beautiful
• 3451-string-compression-iii
• 3501-delete-nodes-from-linked-list-present-in-array
• 3543-count-substrings-that-satisfy-k-constraint-i

LeetCode Topics

Array

Problem Name	Difficulty
0001-two-sum
0015-3sum
0031-next-permutation
0033-search-in-rotated-sorted-array	Medium
0048-rotate-image
0053-maximum-subarray
0056-merge-intervals
0073-set-matrix-zeroes
0075-sort-colors
0085-maximal-rectangle
0088-merge-sorted-array
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0135-candy
0152-maximum-product-subarray
0198-house-robber
0200-number-of-islands
0213-house-robber-ii
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0368-largest-divisible-subset
0399-evaluate-division
0416-partition-equal-subset-sum
0463-island-perimeter	Easy
0494-target-sum
0496-next-greater-element-i
0679-24-game
0689-maximum-sum-of-3-non-overlapping-subarrays
0729-my-calendar-i
0733-flood-fill
0780-max-chunks-to-make-sorted
0787-sliding-puzzle
0934-bitwise-ors-of-subarrays
0940-fruit-into-baskets
0945-snakes-and-ladders
0953-verifying-an-alien-dictionary	Easy
1006-vowel-spellchecker
1025-minimum-cost-for-tickets
1049-minimum-domino-rotations-for-equal-row
1200-minimum-absolute-difference
1227-number-of-equivalent-domino-pairs
1319-unique-number-of-occurrences
1330-reverse-subarray-to-maximize-array-value	Hard
1396-count-servers-that-communicate
1468-check-if-n-and-its-double-exist
1477-product-of-the-last-k-numbers
1478-maximum-number-of-events-that-can-be-attended
1510-find-lucky-integer-in-an-array
1524-string-matching-in-an-array
1536-minimum-swaps-to-arrange-a-binary-grid	Medium
1570-final-prices-with-a-special-discount-in-a-shop
1656-count-good-triplets
1722-minimize-hamming-distance-after-swap-operations	Medium
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1819-construct-the-lexicographically-largest-valid-sequence
1855-maximum-distance-between-a-pair-of-values	Medium
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
1927-maximum-ascending-subarray-sum
1980-find-unique-binary-string	Medium
1993-sum-of-all-subset-xor-totals
1995-finding-pairs-with-a-certain-sum
2022-maximum-alternating-subsequence-sum
2089-maximum-matrix-sum
2144-maximum-difference-between-increasing-elements
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2180-maximum-number-of-tasks-you-can-assign
2204-find-subsequence-of-length-k-with-the-largest-sum
2229-maximum-fruits-harvested-after-at-most-k-steps
2232-adding-spaces-to-a-string
2237-longest-palindrome-by-concatenating-two-letter-words
2262-solving-questions-with-brainpower
2277-count-equal-and-divisible-pairs-in-an-array
2280-count-good-triplets-in-an-array
2308-divide-array-into-equal-pairs
2343-count-unguarded-cells-in-the-grid
2358-number-of-ways-to-split-array
2387-partition-array-such-that-maximum-difference-is-k
2402-meeting-rooms-iii
2465-shifting-letters-ii
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2478-longest-nice-subarray
2479-meeting-rooms-iii
2529-range-product-queries-of-powers
2533-bitwise-xor-of-all-pairings
2552-maximum-sum-of-distinct-subarrays-with-length-k
2626-count-the-number-of-good-subarrays
2665-minimum-time-to-repair-cars
2681-put-marbles-in-bags
2691-count-vowel-strings-in-ranges
2695-find-score-of-an-array-after-marking-all-elements
2720-minimize-the-maximum-difference-of-pairs
2770-maximum-number-of-jumps-to-reach-the-last-index	Medium
2868-continuous-subarrays
2891-maximum-beauty-of-an-array-after-applying-operation
2906-construct-product-matrix	Medium
2915-count-of-interesting-subarrays
3070-count-submatrices-with-top-left-element-and-sum-less-than-k	Medium
3093-longest-common-suffix-queries	Hard
3143-longest-unequal-adjacent-groups-subsequence-i
3152-maximum-value-of-an-ordered-triplet-ii
3154-maximum-value-of-an-ordered-triplet-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3219-make-lexicographically-smallest-array-by-swapping-elements
3227-find-missing-and-repeated-values
3278-find-the-number-of-ways-to-place-people-i
3296-minimum-number-of-seconds-to-make-mountain-height-zero	Medium
3300-minimum-element-after-replacement-with-digit-sum	Easy
3307-find-the-maximum-sum-of-node-values
3309-count-prefix-and-suffix-pairs-i
3321-type-of-triangle
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3427-special-array-ii
3429-special-array-i
3517-shortest-distance-after-road-addition-queries-i
3546-equal-sum-grid-partition-i	Medium
3555-final-array-state-after-k-multiplication-operations-i
3621-minimum-operations-to-make-array-values-equal-to-k
3627-find-minimum-time-to-reach-last-room-i
3643-zero-array-transformation-ii
3647-zero-array-transformation-iii
3648-find-the-maximum-number-of-fruits-collected
3741-reschedule-meetings-for-maximum-free-time-ii
3748-sort-matrix-by-diagonals

Binary Search

Problem Name	Difficulty
0033-search-in-rotated-sorted-array	Medium
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0729-my-calendar-i
1468-check-if-n-and-its-double-exist
1855-maximum-distance-between-a-pair-of-values	Medium
1886-minimum-limit-of-balls-in-a-bag
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2180-maximum-number-of-tasks-you-can-assign
2229-maximum-fruits-harvested-after-at-most-k-steps
2280-count-good-triplets-in-an-array
2665-minimum-time-to-repair-cars
2720-minimize-the-maximum-difference-of-pairs
2891-maximum-beauty-of-an-array-after-applying-operation
3267-find-longest-special-substring-that-occurs-thrice-i
3296-minimum-number-of-seconds-to-make-mountain-height-zero	Medium
3427-special-array-ii
3643-zero-array-transformation-ii

Design

Problem Name	Difficulty
0676-implement-magic-dictionary
0729-my-calendar-i
1477-product-of-the-last-k-numbers
1622-fancy-sequence	Hard
1995-finding-pairs-with-a-certain-sum

Segment Tree

Problem Name	Difficulty
0729-my-calendar-i
1622-fancy-sequence	Hard
2280-count-good-triplets-in-an-array

Ordered Set

Problem Name	Difficulty
0729-my-calendar-i
2280-count-good-triplets-in-an-array
2868-continuous-subarrays

Hash Table

Problem Name	Difficulty
0001-two-sum
0073-set-matrix-zeroes
0133-clone-graph
0141-linked-list-cycle
0496-next-greater-element-i
0676-implement-magic-dictionary
0768-partition-labels
0940-fruit-into-baskets
0953-verifying-an-alien-dictionary	Easy
1006-vowel-spellchecker
1218-lowest-common-ancestor-of-deepest-leaves
1227-number-of-equivalent-domino-pairs
1264-maximum-number-of-words-you-can-type
1319-unique-number-of-occurrences
1460-number-of-substrings-containing-all-three-characters
1468-check-if-n-and-its-double-exist
1502-construct-k-palindrome-strings
1510-find-lucky-integer-in-an-array
1915-check-if-one-string-swap-can-make-strings-equal
1980-find-unique-binary-string	Medium
1986-largest-color-value-in-a-directed-graph
1995-finding-pairs-with-a-certain-sum
2059-unique-length-3-palindromic-subsequences
2204-find-subsequence-of-length-k-with-the-largest-sum
2237-longest-palindrome-by-concatenating-two-letter-words
2300-construct-string-with-repeat-limit
2308-divide-array-into-equal-pairs
2402-meeting-rooms-iii
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2479-meeting-rooms-iii
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2552-maximum-sum-of-distinct-subarrays-with-length-k
2599-take-k-of-each-character-from-left-and-right
2626-count-the-number-of-good-subarrays
2677-cousins-in-binary-tree-ii
2695-find-score-of-an-array-after-marking-all-elements
2915-count-of-interesting-subarrays
3120-count-the-number-of-special-characters-i	Easy
3227-find-missing-and-repeated-values
3267-find-longest-special-substring-that-occurs-thrice-i
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3455-minimum-length-of-string-after-operations
3548-find-the-count-of-good-integers
3621-minimum-operations-to-make-array-values-equal-to-k
3629-total-characters-in-string-after-transformations-i
3753-maximum-difference-between-even-and-odd-frequency-i

Stack

Problem Name	Difficulty
0085-maximal-rectangle
0496-next-greater-element-i
0780-max-chunks-to-make-sorted
1197-parsing-a-boolean-expression
1570-final-prices-with-a-special-discount-in-a-shop
1653-minimum-deletions-to-make-string-balanced
2520-using-a-robot-to-print-the-lexicographically-smallest-string
3445-lexicographically-minimum-string-after-removing-stars
3447-clear-digits

Monotonic Stack

Problem Name	Difficulty
0085-maximal-rectangle
0496-next-greater-element-i
0780-max-chunks-to-make-sorted
1570-final-prices-with-a-special-discount-in-a-shop

String

Problem Name	Difficulty
0093-restore-ip-addresses
0399-evaluate-division
0676-implement-magic-dictionary
0712-minimum-ascii-delete-sum-for-two-strings
0768-partition-labels
0793-swap-adjacent-in-lr-string
0812-rotate-string
0868-push-dominoes
0953-verifying-an-alien-dictionary	Easy
1006-vowel-spellchecker
1197-parsing-a-boolean-expression
1250-longest-common-subsequence
1264-maximum-number-of-words-you-can-type
1460-number-of-substrings-containing-all-three-characters
1502-construct-k-palindrome-strings
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
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
1653-minimum-deletions-to-make-string-balanced
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1758-minimum-changes-to-make-alternating-binary-string	Easy
1871-jump-game-vii	Medium
1894-merge-strings-alternately
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1915-check-if-one-string-swap-can-make-strings-equal
1980-find-unique-binary-string	Medium
2059-unique-length-3-palindromic-subsequences
2140-longest-subsequence-repeated-k-times
2232-adding-spaces-to-a-string
2237-longest-palindrome-by-concatenating-two-letter-words
2260-divide-a-string-into-groups-of-size-k
2300-construct-string-with-repeat-limit
2346-largest-3-same-digit-number-in-string
2414-move-pieces-to-obtain-a-string
2465-shifting-letters-ii
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2599-take-k-of-each-character-from-left-and-right
2691-count-vowel-strings-in-ranges
3018-make-string-a-subsequence-using-cyclic-increments
3093-longest-common-suffix-queries	Hard
3120-count-the-number-of-special-characters-i	Easy
3143-longest-unequal-adjacent-groups-subsequence-i
3174-minimum-number-of-changes-to-make-binary-string-beautiful
3243-count-the-number-of-powerful-integers
3267-find-longest-special-substring-that-occurs-thrice-i
3309-count-prefix-and-suffix-pairs-i
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3447-clear-digits
3455-minimum-length-of-string-after-operations
3617-find-the-original-typed-string-i
3629-total-characters-in-string-after-transformations-i
3637-count-number-of-balanced-permutations
3753-maximum-difference-between-even-and-odd-frequency-i

Recursion

Problem Name	Difficulty
0206-reverse-linked-list
0231-power-of-two
0326-power-of-three
0342-power-of-four
1013-fibonacci-number
1197-parsing-a-boolean-expression
2050-count-good-numbers
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii

Tree

Problem Name	Difficulty
0100-same-tree
0199-binary-tree-right-side-view
0515-find-largest-value-in-each-tree-row
1218-lowest-common-ancestor-of-deepest-leaves
2493-reverse-odd-levels-of-binary-tree
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2677-cousins-in-binary-tree-ii
3307-find-the-maximum-sum-of-node-values
3439-find-minimum-diameter-after-merging-two-trees

Depth-First Search

Problem Name	Difficulty
0100-same-tree
0133-clone-graph
0199-binary-tree-right-side-view
0200-number-of-islands
0386-lexicographical-numbers
0399-evaluate-division
0463-island-perimeter	Easy
0515-find-largest-value-in-each-tree-row
0676-implement-magic-dictionary
0733-flood-fill
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
1218-lowest-common-ancestor-of-deepest-leaves
1396-count-servers-that-communicate
1558-course-schedule-iv
1722-minimize-hamming-distance-after-swap-operations	Medium
2439-longest-cycle-in-a-graph
2493-reverse-odd-levels-of-binary-tree
2677-cousins-in-binary-tree-ii
3439-find-minimum-diameter-after-merging-two-trees

Breadth-First Search

Problem Name	Difficulty
0100-same-tree
0133-clone-graph
0199-binary-tree-right-side-view
0200-number-of-islands
0399-evaluate-division
0463-island-perimeter	Easy
0515-find-largest-value-in-each-tree-row
0733-flood-fill
0787-sliding-puzzle
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0945-snakes-and-ladders
1218-lowest-common-ancestor-of-deepest-leaves
1396-count-servers-that-communicate
1558-course-schedule-iv
2439-longest-cycle-in-a-graph
2493-reverse-odd-levels-of-binary-tree
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2677-cousins-in-binary-tree-ii
3439-find-minimum-diameter-after-merging-two-trees
3517-shortest-distance-after-road-addition-queries-i

Binary Tree

Problem Name	Difficulty
0100-same-tree
0199-binary-tree-right-side-view
0515-find-largest-value-in-each-tree-row
1218-lowest-common-ancestor-of-deepest-leaves
2493-reverse-odd-levels-of-binary-tree
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2677-cousins-in-binary-tree-ii

String Matching

Problem Name	Difficulty
0812-rotate-string
1524-string-matching-in-an-array
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
3309-count-prefix-and-suffix-pairs-i

Dynamic Programming

Problem Name	Difficulty
0053-maximum-subarray
0070-climbing-stairs
0085-maximal-rectangle
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0152-maximum-product-subarray
0198-house-robber
0213-house-robber-ii
0300-longest-increasing-subsequence
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0494-target-sum
0689-maximum-sum-of-3-non-overlapping-subarrays
0712-minimum-ascii-delete-sum-for-two-strings
0799-champagne-tower
0803-cheapest-flights-within-k-stops
0868-push-dominoes
0934-bitwise-ors-of-subarrays
1013-fibonacci-number
1025-minimum-cost-for-tickets
1250-longest-common-subsequence
1653-minimum-deletions-to-make-string-balanced
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1871-jump-game-vii	Medium
1986-largest-color-value-in-a-directed-graph
2022-maximum-alternating-subsequence-sum
2028-the-earliest-and-latest-rounds-where-players-compete
2090-number-of-ways-to-arrive-at-destination
2164-two-best-non-overlapping-events
2262-solving-questions-with-brainpower
2562-count-ways-to-build-good-strings
2770-maximum-number-of-jumps-to-reach-the-last-index	Medium
2882-ways-to-express-an-integer-as-sum-of-powers
3129-find-all-possible-stable-binary-arrays-i	Medium
3143-longest-unequal-adjacent-groups-subsequence-i
3243-count-the-number-of-powerful-integers
3307-find-the-maximum-sum-of-node-values
3629-total-characters-in-string-after-transformations-i
3637-count-number-of-balanced-permutations
3648-find-the-maximum-number-of-fruits-collected

Divide and Conquer

Problem Name	Difficulty
0053-maximum-subarray
2280-count-good-triplets-in-an-array

Math

Problem Name	Difficulty
0048-rotate-image
0070-climbing-stairs
0231-power-of-two
0326-power-of-three
0342-power-of-four
0368-largest-divisible-subset
0679-24-game
0903-implement-rand10-using-rand7
0915-generate-random-point-in-a-circle
1013-fibonacci-number
1330-reverse-subarray-to-maximize-array-value	Hard
1477-product-of-the-last-k-numbers
1529-max-difference-you-can-get-from-changing-an-integer
1622-fancy-sequence	Hard
1889-check-if-number-is-a-sum-of-powers-of-three
1993-sum-of-all-subset-xor-totals
2050-count-good-numbers
2202-sum-of-k-mirror-numbers
2610-closest-prime-numbers-in-range
2704-maximum-difference-by-remapping-a-digit
2802-find-the-punishment-number-of-an-integer
2998-count-symmetric-integers
3172-divisible-and-non-divisible-sums-difference
3201-distribute-candies-among-children-ii
3227-find-missing-and-repeated-values
3243-count-the-number-of-powerful-integers
3278-find-the-number-of-ways-to-place-people-i
3296-minimum-number-of-seconds-to-make-mountain-height-zero	Medium
3300-minimum-element-after-replacement-with-digit-sum	Easy
3321-type-of-triangle
3548-find-the-count-of-good-integers
3555-final-array-state-after-k-multiplication-operations-i
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii
3629-total-characters-in-string-after-transformations-i
3637-count-number-of-balanced-permutations
3830-find-closest-person

Matrix

Problem Name	Difficulty
0048-rotate-image
0073-set-matrix-zeroes
0085-maximal-rectangle
0200-number-of-islands
0463-island-perimeter	Easy
0733-flood-fill
0787-sliding-puzzle
0945-snakes-and-ladders
1396-count-servers-that-communicate
1536-minimum-swaps-to-arrange-a-binary-grid	Medium
2089-maximum-matrix-sum
2343-count-unguarded-cells-in-the-grid
2906-construct-product-matrix	Medium
3070-count-submatrices-with-top-left-element-and-sum-less-than-k	Medium
3227-find-missing-and-repeated-values
3546-equal-sum-grid-partition-i	Medium
3627-find-minimum-time-to-reach-last-room-i
3648-find-the-maximum-number-of-fruits-collected
3748-sort-matrix-by-diagonals

Sorting

Problem Name	Difficulty
0015-3sum
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0368-largest-divisible-subset
0780-max-chunks-to-make-sorted
1200-minimum-absolute-difference
1468-check-if-n-and-its-double-exist
1478-maximum-number-of-events-that-can-be-attended
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2180-maximum-number-of-tasks-you-can-assign
2204-find-subsequence-of-length-k-with-the-largest-sum
2387-partition-array-such-that-maximum-difference-is-k
2402-meeting-rooms-iii
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2479-meeting-rooms-iii
2681-put-marbles-in-bags
2695-find-score-of-an-array-after-marking-all-elements
2891-maximum-beauty-of-an-array-after-applying-operation
3219-make-lexicographically-smallest-array-by-swapping-elements
3278-find-the-number-of-ways-to-place-people-i
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3360-minimum-deletions-to-make-string-k-special
3647-zero-array-transformation-iii
3748-sort-matrix-by-diagonals

Sliding Window

Problem Name	Difficulty
0940-fruit-into-baskets
1460-number-of-substrings-containing-all-three-characters
1871-jump-game-vii	Medium
2229-maximum-fruits-harvested-after-at-most-k-steps
2478-longest-nice-subarray
2552-maximum-sum-of-distinct-subarrays-with-length-k
2599-take-k-of-each-character-from-left-and-right
2626-count-the-number-of-good-subarrays
2868-continuous-subarrays
2891-maximum-beauty-of-an-array-after-applying-operation
3267-find-longest-special-substring-that-occurs-thrice-i

Database

Problem Name	Difficulty
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
1452-restaurant-growth
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

Simulation

Problem Name	Difficulty
2232-adding-spaces-to-a-string
2260-divide-a-string-into-groups-of-size-k
2343-count-unguarded-cells-in-the-grid
2402-meeting-rooms-iii
2479-meeting-rooms-iii
2695-find-score-of-an-array-after-marking-all-elements
3447-clear-digits
3555-final-array-state-after-k-multiplication-operations-i
3600-find-the-k-th-character-in-string-game-i

Greedy

Problem Name	Difficulty
0135-candy
0768-partition-labels
0780-max-chunks-to-make-sorted
1049-minimum-domino-rotations-for-equal-row
1330-reverse-subarray-to-maximize-array-value	Hard
1478-maximum-number-of-events-that-can-be-attended
1502-construct-k-palindrome-strings
1529-max-difference-you-can-get-from-changing-an-integer
1536-minimum-swaps-to-arrange-a-binary-grid	Medium
1917-maximum-average-pass-ratio
2089-maximum-matrix-sum
2140-longest-subsequence-repeated-k-times
2180-maximum-number-of-tasks-you-can-assign
2237-longest-palindrome-by-concatenating-two-letter-words
2300-construct-string-with-repeat-limit
2387-partition-array-such-that-maximum-difference-is-k
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2681-put-marbles-in-bags
2704-maximum-difference-by-remapping-a-digit
2720-minimize-the-maximum-difference-of-pairs
3143-longest-unequal-adjacent-groups-subsequence-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3296-minimum-number-of-seconds-to-make-mountain-height-zero	Medium
3307-find-the-maximum-sum-of-node-values
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3647-zero-array-transformation-iii
3741-reschedule-meetings-for-maximum-free-time-ii

Graph

Problem Name	Difficulty
0133-clone-graph
0399-evaluate-division
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
1558-course-schedule-iv
1986-largest-color-value-in-a-directed-graph
2090-number-of-ways-to-arrive-at-destination
2439-longest-cycle-in-a-graph
3439-find-minimum-diameter-after-merging-two-trees
3517-shortest-distance-after-road-addition-queries-i
3627-find-minimum-time-to-reach-last-room-i

Two Pointers

Problem Name	Difficulty
0015-3sum
0031-next-permutation
0075-sort-colors
0088-merge-sorted-array
0141-linked-list-cycle
0287-find-the-duplicate-number
0768-partition-labels
0793-swap-adjacent-in-lr-string
0868-push-dominoes
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
1855-maximum-distance-between-a-pair-of-values	Medium
1894-merge-strings-alternately
2232-adding-spaces-to-a-string
2414-move-pieces-to-obtain-a-string
3018-make-string-a-subsequence-using-cyclic-increments

Heap (Priority Queue)

Problem Name	Difficulty
0803-cheapest-flights-within-k-stops
1478-maximum-number-of-events-that-can-be-attended
1917-maximum-average-pass-ratio
2164-two-best-non-overlapping-events
2204-find-subsequence-of-length-k-with-the-largest-sum
2300-construct-string-with-repeat-limit
2402-meeting-rooms-iii
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2479-meeting-rooms-iii
2681-put-marbles-in-bags
2695-find-score-of-an-array-after-marking-all-elements
2868-continuous-subarrays
3296-minimum-number-of-seconds-to-make-mountain-height-zero	Medium
3445-lexicographically-minimum-string-after-removing-stars
3555-final-array-state-after-k-multiplication-operations-i
3627-find-minimum-time-to-reach-last-room-i
3647-zero-array-transformation-iii

Prefix Sum

Problem Name	Difficulty
1477-product-of-the-last-k-numbers
1537-maximum-score-after-splitting-a-string
1871-jump-game-vii	Medium
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
2059-unique-length-3-palindromic-subsequences
2229-maximum-fruits-harvested-after-at-most-k-steps
2358-number-of-ways-to-split-array
2465-shifting-letters-ii
2529-range-product-queries-of-powers
2691-count-vowel-strings-in-ranges
2906-construct-product-matrix	Medium
2915-count-of-interesting-subarrays
3070-count-submatrices-with-top-left-element-and-sum-less-than-k	Medium
3129-find-all-possible-stable-binary-arrays-i	Medium
3427-special-array-ii
3546-equal-sum-grid-partition-i	Medium
3643-zero-array-transformation-ii
3647-zero-array-transformation-iii

Counting

Problem Name	Difficulty
1227-number-of-equivalent-domino-pairs
1396-count-servers-that-communicate
1502-construct-k-palindrome-strings
1510-find-lucky-integer-in-an-array
1915-check-if-one-string-swap-can-make-strings-equal
1986-largest-color-value-in-a-directed-graph
2140-longest-subsequence-repeated-k-times
2237-longest-palindrome-by-concatenating-two-letter-words
2300-construct-string-with-repeat-limit
2308-divide-array-into-equal-pairs
3267-find-longest-special-substring-that-occurs-thrice-i
3360-minimum-deletions-to-make-string-k-special
3455-minimum-length-of-string-after-operations
3629-total-characters-in-string-after-transformations-i
3753-maximum-difference-between-even-and-odd-frequency-i

Queue

Problem Name	Difficulty
2180-maximum-number-of-tasks-you-can-assign
2868-continuous-subarrays

Monotonic Queue

Problem Name	Difficulty
2180-maximum-number-of-tasks-you-can-assign
2868-continuous-subarrays

Backtracking

Problem Name	Difficulty
0093-restore-ip-addresses
0494-target-sum
0679-24-game
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1819-construct-the-lexicographically-largest-valid-sequence
1980-find-unique-binary-string	Medium
1993-sum-of-all-subset-xor-totals
2140-longest-subsequence-repeated-k-times
2802-find-the-punishment-number-of-an-integer

Bit Manipulation

Problem Name	Difficulty
0231-power-of-two
0287-find-the-duplicate-number
0342-power-of-four
0934-bitwise-ors-of-subarrays
1009-complement-of-base-10-integer
1993-sum-of-all-subset-xor-totals
2059-unique-length-3-palindromic-subsequences
2308-divide-array-into-equal-pairs
2478-longest-nice-subarray
2529-range-product-queries-of-powers
2533-bitwise-xor-of-all-pairings
3307-find-the-maximum-sum-of-node-values
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii

Trie

Problem Name	Difficulty
0386-lexicographical-numbers
0440-k-th-smallest-in-lexicographical-order
0676-implement-magic-dictionary
3093-longest-common-suffix-queries	Hard
3309-count-prefix-and-suffix-pairs-i

Rolling Hash

Problem Name	Difficulty
3309-count-prefix-and-suffix-pairs-i

Hash Function

Problem Name	Difficulty
3309-count-prefix-and-suffix-pairs-i

Brainteaser

Problem Name	Difficulty
2533-bitwise-xor-of-all-pairings

Union Find

Problem Name	Difficulty
0200-number-of-islands
0399-evaluate-division
0801-is-graph-bipartite
1396-count-servers-that-communicate
3219-make-lexicographically-smallest-array-by-swapping-elements

Topological Sort

Problem Name	Difficulty
1558-course-schedule-iv
1986-largest-color-value-in-a-directed-graph
2090-number-of-ways-to-arrive-at-destination
2439-longest-cycle-in-a-graph

Data Stream

Problem Name	Difficulty
1477-product-of-the-last-k-numbers

Number Theory

Problem Name	Difficulty
2610-closest-prime-numbers-in-range

Shortest Path

Problem Name	Difficulty
0399-evaluate-division
0803-cheapest-flights-within-k-stops
2090-number-of-ways-to-arrive-at-destination
3627-find-minimum-time-to-reach-last-room-i

Combinatorics

Problem Name	Difficulty
1993-sum-of-all-subset-xor-totals
3201-distribute-candies-among-children-ii
3548-find-the-count-of-good-integers
3637-count-number-of-balanced-permutations

Enumeration

Problem Name	Difficulty
1656-count-good-triplets
1993-sum-of-all-subset-xor-totals
2140-longest-subsequence-repeated-k-times
2202-sum-of-k-mirror-numbers
2998-count-symmetric-integers
3201-distribute-candies-among-children-ii
3278-find-the-number-of-ways-to-place-people-i
3546-equal-sum-grid-partition-i	Medium
3548-find-the-count-of-good-integers
3741-reschedule-meetings-for-maximum-free-time-ii

Memoization

Problem Name	Difficulty
0070-climbing-stairs
1013-fibonacci-number
1986-largest-color-value-in-a-directed-graph
2028-the-earliest-and-latest-rounds-where-players-compete

Geometry

Problem Name	Difficulty
0915-generate-random-point-in-a-circle
3278-find-the-number-of-ways-to-place-people-i

Rejection Sampling

Problem Name	Difficulty
0903-implement-rand10-using-rand7
0915-generate-random-point-in-a-circle

Randomized

Problem Name	Difficulty
0903-implement-rand10-using-rand7
0915-generate-random-point-in-a-circle

Probability and Statistics

Problem Name	Difficulty
0903-implement-rand10-using-rand7

Binary Indexed Tree

Problem Name	Difficulty
2280-count-good-triplets-in-an-array

Merge Sort

Problem Name	Difficulty
2280-count-good-triplets-in-an-array

Linked List

Problem Name	Difficulty
0141-linked-list-cycle
0206-reverse-linked-list
0908-middle-of-the-linked-list

Union-Find

Problem Name	Difficulty
1722-minimize-hamming-distance-after-swap-operations	Medium