LeetCode questions that I've solved.

LeetCode Topics

Linked List

Problem Name	Difficulty
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0061-rotate-list
0083-remove-duplicates-from-sorted-list
0092-reverse-linked-list-ii
0117-populating-next-right-pointers-in-each-node-ii	Medium
0138-copy-list-with-random-pointer	Medium
0141-linked-list-cycle
0206-reverse-linked-list
0355-design-twitter
0816-design-hashset
0817-design-hashmap
1797-design-authentication-manager	Medium

Recursion

Problem Name	Difficulty
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0206-reverse-linked-list
3600-find-the-k-th-character-in-string-game-i

Two Pointers

Problem Name	Difficulty
0011-container-with-most-water
0019-remove-nth-node-from-end-of-list
0061-rotate-list
0075-sort-colors
0088-merge-sorted-array
0141-linked-list-cycle
0189-rotate-array
0202-happy-number
0611-valid-triangle-number
0768-partition-labels
0868-push-dominoes
2265-partition-array-according-to-given-pivot
2320-find-all-k-distant-indices-in-an-array
2392-successful-pairs-of-spells-and-potions
2481-strictly-palindromic-number
2551-apply-operations-to-an-array
2707-merge-two-2d-arrays-by-summing-values
3683-find-the-lexicographically-largest-string-from-the-box-i

Tree

Problem Name	Difficulty
0117-populating-next-right-pointers-in-each-node-ii	Medium
0226-invert-binary-tree
0515-find-largest-value-in-each-tree-row
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1544-count-good-nodes-in-binary-tree
2384-root-equals-sum-of-children
2461-amount-of-time-for-binary-tree-to-be-infected
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level

Depth-First Search

Problem Name	Difficulty
0117-populating-next-right-pointers-in-each-node-ii	Medium
0226-invert-binary-tree
0386-lexicographical-numbers
0515-find-largest-value-in-each-tree-row
0733-flood-fill
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1428-jump-game-iii
1544-count-good-nodes-in-binary-tree
1663-detect-cycles-in-2d-grid
2461-amount-of-time-for-binary-tree-to-be-infected

Breadth-First Search

Problem Name	Difficulty
0117-populating-next-right-pointers-in-each-node-ii	Medium
0226-invert-binary-tree
0515-find-largest-value-in-each-tree-row
0733-flood-fill
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1428-jump-game-iii
1544-count-good-nodes-in-binary-tree
1663-detect-cycles-in-2d-grid
2461-amount-of-time-for-binary-tree-to-be-infected
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level

Binary Tree

Problem Name	Difficulty
0117-populating-next-right-pointers-in-each-node-ii	Medium
0226-invert-binary-tree
0515-find-largest-value-in-each-tree-row
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1544-count-good-nodes-in-binary-tree
2384-root-equals-sum-of-children
2461-amount-of-time-for-binary-tree-to-be-infected
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level

Hash Table

Problem Name	Difficulty
0001-two-sum	Easy
0041-first-missing-positive	Hard
0073-set-matrix-zeroes
0138-copy-list-with-random-pointer	Medium
0141-linked-list-cycle
0169-majority-element	Easy
0202-happy-number
0290-word-pattern
0355-design-twitter
0768-partition-labels
0797-rabbits-in-forest
0816-design-hashset
0817-design-hashmap
0940-fruit-into-baskets
0952-word-subsets
1218-lowest-common-ancestor-of-deepest-leaves
1227-number-of-equivalent-domino-pairs
1364-tuple-with-same-product
1387-find-elements-in-a-contaminated-binary-tree
1500-count-largest-group
1502-construct-k-palindrome-strings
1510-find-lucky-integer-in-an-array
1797-design-authentication-manager	Medium
1915-check-if-one-string-swap-can-make-strings-equal
1995-finding-pairs-with-a-certain-sum
2059-unique-length-3-palindromic-subsequences
2204-find-subsequence-of-length-k-with-the-largest-sum
2215-finding-3-digit-even-numbers
2285-design-bitset
2428-equal-row-and-column-pairs
2461-amount-of-time-for-binary-tree-to-be-infected
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2685-first-completely-painted-row-or-column
2707-merge-two-2d-arrays-by-summing-values
2856-count-complete-subarrays-in-an-array
3227-find-missing-and-repeated-values
3455-minimum-length-of-string-after-operations
3621-minimum-operations-to-make-array-values-equal-to-k
3629-total-characters-in-string-after-transformations-i
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3741-minimum-distance-between-three-equal-elements-ii	Medium
3754-maximum-manhattan-distance-after-k-changes

String

Problem Name	Difficulty
0020-valid-parentheses	Easy
0038-count-and-say
0290-word-pattern
0768-partition-labels
0868-push-dominoes
0952-word-subsets
1058-lexicographically-smallest-equivalent-string
1502-construct-k-palindrome-strings
1537-maximum-score-after-splitting-a-string
1689-partitioning-into-minimum-number-of-deci-binary-numbers	Medium
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1915-check-if-one-string-swap-can-make-strings-equal
2021-remove-all-occurrences-of-a-substring
2059-unique-length-3-palindromic-subsequences
2221-check-if-a-parentheses-string-can-be-valid
2260-divide-a-string-into-groups-of-size-k
2285-design-bitset
2292-counting-words-with-a-given-prefix
2452-words-within-two-edits-of-dictionary	Medium
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2465-shifting-letters-ii
2691-count-vowel-strings-in-ranges
3143-longest-unequal-adjacent-groups-subsequence-i
3194-find-words-containing-character
3309-count-prefix-and-suffix-pairs-i
3447-clear-digits
3455-minimum-length-of-string-after-operations
3612-process-string-with-special-operations-i	Medium
3617-find-the-original-typed-string-i
3629-total-characters-in-string-after-transformations-i
3683-find-the-lexicographically-largest-string-from-the-box-i
3754-maximum-manhattan-distance-after-k-changes

Prefix Sum

Problem Name	Difficulty
1477-product-of-the-last-k-numbers
1537-maximum-score-after-splitting-a-string
1732-find-the-highest-altitude	Easy
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
2059-unique-length-3-palindromic-subsequences
2145-grid-game
2249-count-the-hidden-sequences
2358-number-of-ways-to-split-array
2394-count-subarrays-with-score-less-than-k
2465-shifting-letters-ii
2691-count-vowel-strings-in-ranges
3383-taking-maximum-energy-from-the-mystic-dungeon
3639-zero-array-transformation-i

Array

Problem Name	Difficulty
0001-two-sum	Easy
0011-container-with-most-water
0041-first-missing-positive	Hard
0066-plus-one
0073-set-matrix-zeroes
0075-sort-colors
0088-merge-sorted-array
0118-pascals-triangle
0169-majority-element	Easy
0189-rotate-array
0611-valid-triangle-number
0733-flood-fill
0797-rabbits-in-forest
0816-design-hashset
0817-design-hashmap
0940-fruit-into-baskets
0952-word-subsets
1049-minimum-domino-rotations-for-equal-row
1227-number-of-equivalent-domino-pairs
1293-three-consecutive-odds
1364-tuple-with-same-product
1421-find-numbers-with-even-number-of-digits
1428-jump-game-iii
1475-final-prices-with-a-special-discount-in-a-shop	Easy
1477-product-of-the-last-k-numbers
1510-find-lucky-integer-in-an-array
1656-count-good-triplets
1663-detect-cycles-in-2d-grid
1732-find-the-highest-altitude	Easy
1878-check-if-array-is-sorted-and-rotated
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1927-maximum-ascending-subarray-sum
1995-finding-pairs-with-a-certain-sum
2048-build-array-from-permutation
2145-grid-game
2204-find-subsequence-of-length-k-with-the-largest-sum
2215-finding-3-digit-even-numbers
2249-count-the-hidden-sequences
2265-partition-array-according-to-given-pivot
2277-count-equal-and-divisible-pairs-in-an-array
2285-design-bitset
2292-counting-words-with-a-given-prefix
2320-find-all-k-distant-indices-in-an-array
2358-number-of-ways-to-split-array
2387-partition-array-such-that-maximum-difference-is-k
2392-successful-pairs-of-spells-and-potions
2394-count-subarrays-with-score-less-than-k
2428-equal-row-and-column-pairs
2452-words-within-two-edits-of-dictionary	Medium
2465-shifting-letters-ii
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2533-bitwise-xor-of-all-pairings
2551-apply-operations-to-an-array
2685-first-completely-painted-row-or-column
2691-count-vowel-strings-in-ranges
2707-merge-two-2d-arrays-by-summing-values
2792-neighboring-bitwise-xor
2856-count-complete-subarrays-in-an-array
3143-longest-unequal-adjacent-groups-subsequence-i
3152-maximum-value-of-an-ordered-triplet-ii
3154-maximum-value-of-an-ordered-triplet-i
3194-find-words-containing-character
3213-count-subarrays-where-max-element-appears-at-least-k-times
3227-find-missing-and-repeated-values
3241-divide-array-into-arrays-with-max-difference
3309-count-prefix-and-suffix-pairs-i
3321-type-of-triangle
3332-minimum-operations-to-exceed-threshold-value-ii
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3383-taking-maximum-energy-from-the-mystic-dungeon
3429-special-array-i
3512-minimum-operations-to-make-array-sum-divisible-by-k
3621-minimum-operations-to-make-array-values-equal-to-k
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3639-zero-array-transformation-i
3653-xor-after-range-multiplication-queries-i	Medium
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3685-count-subarrays-of-length-three-with-a-condition
3741-minimum-distance-between-three-equal-elements-ii	Medium
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3790-fruits-into-baskets-ii

Bit Manipulation

Problem Name	Difficulty
0338-counting-bits
2059-unique-length-3-palindromic-subsequences
2509-minimize-xor
2533-bitwise-xor-of-all-pairings
2792-neighboring-bitwise-xor
3600-find-the-k-th-character-in-string-game-i

Trie

Problem Name	Difficulty
0386-lexicographical-numbers
2452-words-within-two-edits-of-dictionary	Medium
3309-count-prefix-and-suffix-pairs-i

Rolling Hash

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

String Matching

Problem Name	Difficulty
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i

Hash Function

Problem Name	Difficulty
0816-design-hashset
0817-design-hashmap
3309-count-prefix-and-suffix-pairs-i

Greedy

Problem Name	Difficulty
0011-container-with-most-water
0611-valid-triangle-number
0768-partition-labels
0797-rabbits-in-forest
1049-minimum-domino-rotations-for-equal-row
1502-construct-k-palindrome-strings
1529-max-difference-you-can-get-from-changing-an-integer
1689-partitioning-into-minimum-number-of-deci-binary-numbers	Medium
2221-check-if-a-parentheses-string-can-be-valid
2387-partition-array-such-that-maximum-difference-is-k
2509-minimize-xor
2704-maximum-difference-by-remapping-a-digit
3143-longest-unequal-adjacent-groups-subsequence-i
3241-divide-array-into-arrays-with-max-difference

Counting

Problem Name	Difficulty
0169-majority-element	Easy
1227-number-of-equivalent-domino-pairs
1364-tuple-with-same-product
1502-construct-k-palindrome-strings
1510-find-lucky-integer-in-an-array
1915-check-if-one-string-swap-can-make-strings-equal
3455-minimum-length-of-string-after-operations
3629-total-characters-in-string-after-transformations-i
3754-maximum-manhattan-distance-after-k-changes

Math

Problem Name	Difficulty
0066-plus-one
0069-sqrtx
0189-rotate-array
0202-happy-number
0797-rabbits-in-forest
1344-angle-between-hands-of-a-clock	Medium
1421-find-numbers-with-even-number-of-digits
1477-product-of-the-last-k-numbers
1500-count-largest-group
1529-max-difference-you-can-get-from-changing-an-integer
2481-strictly-palindromic-number
2649-count-total-number-of-colored-cells
2704-maximum-difference-by-remapping-a-digit
2998-count-symmetric-integers
3172-divisible-and-non-divisible-sums-difference
3201-distribute-candies-among-children-ii
3227-find-missing-and-repeated-values
3321-type-of-triangle
3512-minimum-operations-to-make-array-sum-divisible-by-k
3600-find-the-k-th-character-in-string-game-i
3629-total-characters-in-string-after-transformations-i
3754-maximum-manhattan-distance-after-k-changes

Binary Search

Problem Name	Difficulty
0069-sqrtx
0611-valid-triangle-number
2392-successful-pairs-of-spells-and-potions
2394-count-subarrays-with-score-less-than-k
3790-fruits-into-baskets-ii

Stack

Problem Name	Difficulty
0020-valid-parentheses	Easy
1475-final-prices-with-a-special-discount-in-a-shop	Easy
2021-remove-all-occurrences-of-a-substring
2221-check-if-a-parentheses-string-can-be-valid
3447-clear-digits

Matrix

Problem Name	Difficulty
0073-set-matrix-zeroes
0733-flood-fill
1663-detect-cycles-in-2d-grid
2145-grid-game
2428-equal-row-and-column-pairs
2685-first-completely-painted-row-or-column
3227-find-missing-and-repeated-values
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Union Find

Problem Name	Difficulty
1058-lexicographically-smallest-equivalent-string
1663-detect-cycles-in-2d-grid

Brainteaser

Problem Name	Difficulty
2481-strictly-palindromic-number
2533-bitwise-xor-of-all-pairings

Design

Problem Name	Difficulty
0355-design-twitter
0816-design-hashset
0817-design-hashmap
1387-find-elements-in-a-contaminated-binary-tree
1477-product-of-the-last-k-numbers
1797-design-authentication-manager	Medium
1995-finding-pairs-with-a-certain-sum
2285-design-bitset

Heap (Priority Queue)

Problem Name	Difficulty
0355-design-twitter
2204-find-subsequence-of-length-k-with-the-largest-sum
2473-max-sum-of-a-pair-with-equal-sum-of-digits
3332-minimum-operations-to-exceed-threshold-value-ii
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Simulation

Problem Name	Difficulty
2021-remove-all-occurrences-of-a-substring
2048-build-array-from-permutation
2260-divide-a-string-into-groups-of-size-k
2265-partition-array-according-to-given-pivot
2428-equal-row-and-column-pairs
2551-apply-operations-to-an-array
3332-minimum-operations-to-exceed-threshold-value-ii
3447-clear-digits
3600-find-the-k-th-character-in-string-game-i
3612-process-string-with-special-operations-i	Medium
3653-xor-after-range-multiplication-queries-i	Medium
3790-fruits-into-baskets-ii

Sorting

Problem Name	Difficulty
0075-sort-colors
0088-merge-sorted-array
0169-majority-element	Easy
0611-valid-triangle-number
2204-find-subsequence-of-length-k-with-the-largest-sum
2215-finding-3-digit-even-numbers
2387-partition-array-such-that-maximum-difference-is-k
2392-successful-pairs-of-spells-and-potions
2473-max-sum-of-a-pair-with-equal-sum-of-digits
3241-divide-array-into-arrays-with-max-difference
3321-type-of-triangle

Data Stream

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

Sliding Window

Problem Name	Difficulty
0940-fruit-into-baskets
2394-count-subarrays-with-score-less-than-k
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2856-count-complete-subarrays-in-an-array
3213-count-subarrays-where-max-element-appears-at-least-k-times

Enumeration

Problem Name	Difficulty
1656-count-good-triplets
2215-finding-3-digit-even-numbers
2998-count-symmetric-integers
3201-distribute-candies-among-children-ii
3683-find-the-lexicographically-largest-string-from-the-box-i

Database

Problem Name	Difficulty
0180-consecutive-numbers
0197-rising-temperature
0570-managers-with-at-least-5-direct-reports
0577-employee-bonus
0584-find-customer-referee
0595-big-countries
0596-classes-more-than-5-students
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
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
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

Dynamic Programming

Problem Name	Difficulty
0118-pascals-triangle
0338-counting-bits
0868-push-dominoes
3143-longest-unequal-adjacent-groups-subsequence-i
3629-total-characters-in-string-after-transformations-i

Graph

Problem Name	Difficulty
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Shortest Path

Problem Name	Difficulty
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Combinatorics

Problem Name	Difficulty
3201-distribute-candies-among-children-ii

Segment Tree

Problem Name	Difficulty
3790-fruits-into-baskets-ii

Ordered Set

Problem Name	Difficulty
3790-fruits-into-baskets-ii

Divide and Conquer

Problem Name	Difficulty
0169-majority-element	Easy
3653-xor-after-range-multiplication-queries-i	Medium

Doubly-Linked List

Problem Name	Difficulty
1797-design-authentication-manager	Medium

Monotonic Stack

Problem Name	Difficulty
1475-final-prices-with-a-special-discount-in-a-shop	Easy