LeetcodeProblems

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

LeetCode Topics

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0049-group-anagrams
0073-set-matrix-zeroes
0128-longest-consecutive-sequence
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0169-majority-element
0205-isomorphic-strings
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0387-first-unique-character-in-a-string
0389-find-the-difference
0442-find-all-duplicates-in-an-array
0448-find-all-numbers-disappeared-in-an-array
0451-sort-characters-by-frequency
0496-next-greater-element-i
0560-subarray-sum-equals-k
0782-jewels-and-stones
0804-unique-morse-code-words
0961-n-repeated-element-in-size-2n-array
0974-subarray-sums-divisible-by-k
1064-smallest-integer-divisible-by-k
1189-maximum-number-of-balloons
1248-count-number-of-nice-subarrays
1256-rank-transform-of-an-array
1331-rank-transform-of-an-array
1436-destination-city
1442-count-triplets-that-can-form-two-arrays-of-equal-xor
1482-how-many-numbers-are-smaller-than-the-current-number
1635-number-of-good-pairs
1674-minimum-moves-to-make-array-complementary
1748-sum-of-unique-elements
1786-count-the-number-of-consistent-strings
1832-check-if-the-sentence-is-pangram
1935-maximum-number-of-words-you-can-type
1980-find-unique-binary-string
2006-count-number-of-pairs-with-absolute-difference-k
2107-find-unique-binary-string
2215-finding-3-digit-even-numbers
2215-find-the-difference-of-two-arrays
2274-keep-multiplying-found-values-by-two
2308-divide-array-into-equal-pairs
2309-greatest-english-letter-in-upper-and-lower-case
2325-decode-the-message
2357-make-array-zero-by-subtracting-equal-amounts
2367-number-of-arithmetic-triplets
2404-most-frequent-even-element
2442-count-number-of-distinct-integers-after-reverse-operations
2502-sort-the-people
2540-minimum-common-value
2566-number-of-unequal-triplets-in-array
2784-check-if-array-is-good
2847-find-maximum-number-of-string-pairs
2956-find-common-elements-between-two-arrays
2965-find-missing-and-repeated-values
3120-count-the-number-of-special-characters-i
3121-count-the-number-of-special-characters-ii
3184-count-pairs-that-form-a-complete-day-i
3408-count-the-number-of-special-characters-i
3438-find-valid-pair-of-adjacent-digits-in-string
3446-find-the-number-of-good-pairs-i
3501-delete-nodes-from-linked-list-present-in-array
3507-minimum-pair-removal-to-sort-array-i
3581-the-two-sneaky-numbers-of-digitville
3731-find-missing-elements
3760-maximum-substrings-with-distinct-start
4008-restore-finishing-order

String

0003-longest-substring-without-repeating-characters
0014-longest-common-prefix
0043-multiply-strings
0049-group-anagrams
0058-length-of-last-word
0067-add-binary
0125-valid-palindrome
0151-reverse-words-in-a-string
0168-excel-sheet-column-title
0205-isomorphic-strings
0242-valid-anagram
0344-reverse-string
0345-reverse-vowels-of-a-string
0387-first-unique-character-in-a-string
0389-find-the-difference
0412-fizz-buzz
0415-add-strings
0451-sort-characters-by-frequency
0459-repeated-substring-pattern
0504-base-7
0520-detect-capital
0551-student-attendance-record-i
0657-robot-return-to-origin
0742-to-lower-case
0782-jewels-and-stones
0796-rotate-string
0804-unique-morse-code-words
0953-reverse-only-letters
1146-greatest-common-divisor-of-strings
1189-maximum-number-of-balloons
1205-defanging-an-ip-address
1260-day-of-the-year
1274-number-of-days-between-two-dates
1341-split-a-string-in-balanced-strings
1436-destination-city
1455-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1528-shuffle-string
1542-consecutive-characters
1614-maximum-nesting-depth-of-the-parentheses
1636-number-of-substrings-with-only-1s
1689-partitioning-into-minimum-number-of-deci-binary-numbers
1758-minimum-changes-to-make-alternating-binary-string
1773-count-items-matching-a-rule
1781-check-if-two-string-arrays-are-equivalent
1784-check-if-binary-string-has-at-most-one-segment-of-ones
1786-count-the-number-of-consistent-strings
1797-goal-parser-interpretation
1832-check-if-the-sentence-is-pangram
1859-sorting-the-sentence
1935-maximum-number-of-words-you-can-type
1944-truncate-sentence
1967-number-of-strings-that-appear-as-substrings-in-word
1980-find-unique-binary-string
1999-longer-contiguous-segments-of-ones-than-zeros
2076-sum-of-digits-of-string-after-convert
2107-find-unique-binary-string
2128-reverse-prefix-of-word
2137-final-value-of-variable-after-performing-operations
2185-counting-words-with-a-given-prefix
2211-count-collisions-on-a-road
2219-maximum-number-of-words-found-in-sentences
2235-capitalize-the-title
2243-calculate-digit-sum-of-a-string
2255-count-prefixes-of-a-given-string
2309-greatest-english-letter-in-upper-and-lower-case
2315-count-asterisks
2325-decode-the-message
2502-sort-the-people
2536-determine-if-two-events-have-conflict
2847-find-maximum-number-of-string-pairs
2864-maximum-odd-binary-number
2881-split-strings-by-separator
2886-faulty-keyboard
3120-count-the-number-of-special-characters-i
3121-count-the-number-of-special-characters-ii
3174-clear-digits
3194-find-words-containing-character
3280-convert-date-to-binary
3340-check-balanced-string
3379-score-of-a-string
3408-count-the-number-of-special-characters-i
3438-find-valid-pair-of-adjacent-digits-in-string
3451-string-compression-iii
3567-convert-date-to-binary
3602-hexadecimal-and-hexatrigesimal-conversion
3612-process-string-with-special-operations-i
3760-maximum-substrings-with-distinct-start
3768-check-if-digits-are-equal-in-string-after-operations-i
3794-reverse-string-prefix
3811-reverse-degree-of-a-string
3838-weighted-word-mapping

Sorting

0015-3sum
0018-4sum
0049-group-anagrams
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0148-sort-list
0169-majority-element
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0389-find-the-difference
0435-non-overlapping-intervals
0451-sort-characters-by-frequency
0455-assign-cookies
0628-maximum-product-of-three-numbers
0646-maximum-length-of-pair-chain
0948-sort-an-array
1019-squares-of-a-sorted-array
1200-minimum-absolute-difference
1256-rank-transform-of-an-array
1331-rank-transform-of-an-array
1482-how-many-numbers-are-smaller-than-the-current-number
1561-maximum-number-of-coins-you-can-get
1665-minimum-initial-energy-to-finish-tasks
1742-widest-vertical-area-between-two-points-containing-no-points
1833-maximum-ice-cream-bars
1859-sorting-the-sentence
1877-minimize-maximum-pair-sum-in-array
1984-minimum-difference-between-highest-and-lowest-of-k-scores
2126-destroying-asteroids
2144-minimum-cost-of-buying-candies-with-discount
2148-minimum-number-of-moves-to-seat-everyone
2210-find-target-indices-after-sorting-array
2215-finding-3-digit-even-numbers
2264-minimum-sum-of-four-digit-number-after-splitting-digits
2274-keep-multiplying-found-values-by-two
2357-make-array-zero-by-subtracting-equal-amounts
2502-sort-the-people
2566-number-of-unequal-triplets-in-array
2578-split-with-minimum-sum
2784-check-if-array-is-good
2917-count-pairs-whose-sum-is-less-than-target
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3074-apple-redistribution-into-boxes
3226-minimum-number-game
3471-minimum-average-of-smallest-and-largest-elements
3731-find-missing-elements
3778-transform-array-by-parity
3867-sum-of-gcd-of-formed-pairs

Math

0007-reverse-integer
0009-palindrome-number
0029-divide-two-integers
0043-multiply-strings
0048-rotate-image
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0168-excel-sheet-column-title
0189-rotate-array
0231-power-of-two
0268-missing-number
0292-nim-game
0326-power-of-three
0342-power-of-four
0371-sum-of-two-integers
0412-fizz-buzz
0415-add-strings
0492-construct-the-rectangle
0504-base-7
0628-maximum-product-of-three-numbers
1013-fibonacci-number
1064-smallest-integer-divisible-by-k
1146-greatest-common-divisor-of-strings
1248-count-number-of-nice-subarrays
1252-cells-with-odd-values-in-a-matrix
1260-day-of-the-year
1266-minimum-time-visiting-all-points
1274-number-of-days-between-two-dates
1289-day-of-the-week
1290-convert-binary-number-in-a-linked-list-to-integer
1304-find-n-unique-integers-sum-up-to-zero
1323-maximum-69-number
1406-subtract-the-product-and-sum-of-digits-of-an-integer
1421-find-numbers-with-even-number-of-digits
1442-count-triplets-that-can-form-two-arrays-of-equal-xor
1444-number-of-steps-to-reduce-a-number-to-zero
1551-minimum-operations-to-make-array-equal
1561-maximum-number-of-coins-you-can-get
1610-xor-operation-in-an-array
1635-number-of-good-pairs
1636-number-of-substrings-with-only-1s
1641-count-sorted-vowel-strings
1693-sum-of-all-odd-length-subarrays
1806-count-of-matches-in-tournament
1817-calculate-money-in-leetcode-bank
1823-find-the-winner-of-the-circular-game
1835-find-xor-sum-of-all-pairs-bitwise-and
1889-check-if-number-is-a-sum-of-powers-of-three
1925-count-square-sum-triples
1965-sum-of-digits-in-base-k
1993-sum-of-all-subset-xor-totals
2083-three-divisors
2106-find-greatest-common-divisor-of-array
2119-a-number-after-a-double-reversal
2180-count-integers-with-even-digit-sum
2235-add-two-integers
2264-minimum-sum-of-four-digit-number-after-splitting-digits
2288-count-operations-to-obtain-zero
2383-add-two-integers
2427-number-of-common-factors
2442-count-number-of-distinct-integers-after-reverse-operations
2481-strictly-palindromic-number
2491-smallest-even-multiple
2544-alternating-digit-sum
2556-convert-the-temperature
2571-find-the-pivot-integer
2578-split-with-minimum-sum
2619-categorize-box-according-to-criteria
2812-find-the-maximum-achievable-number
2864-maximum-odd-binary-number
2965-find-missing-and-repeated-values
2998-count-symmetric-integers
3172-divisible-and-non-divisible-sums-difference
3190-find-minimum-operations-to-make-all-elements-divisible-by-three
3232-find-if-digit-game-can-be-won
3280-convert-date-to-binary
3300-minimum-element-after-replacement-with-digit-sum
3371-harshad-number
3432-count-partitions-with-even-sum-difference
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3550-smallest-index-with-digit-sum-equal-to-index
3555-final-array-state-after-k-multiplication-operations-i
3567-convert-date-to-binary
3581-the-two-sneaky-numbers-of-digitville
3602-hexadecimal-and-hexatrigesimal-conversion
3676-smallest-number-with-all-set-bits
3736-minimum-moves-to-equal-array-elements-iii
3754-concatenate-non-zero-digits-and-multiply-by-sum-i
3768-check-if-digits-are-equal-in-string-after-operations-i
3783-mirror-distance-of-an-integer
3830-find-closest-person
3846-minimum-operations-to-make-array-sum-divisible-by-k
3867-sum-of-gcd-of-formed-pairs
3870-count-commas-in-range
3918-check-divisibility-by-digit-sum-and-product
3995-gcd-of-odd-and-even-sums

Bit Manipulation

0029-divide-two-integers
0067-add-binary
0190-reverse-bits
0191-number-of-1-bits
0222-count-complete-tree-nodes
0231-power-of-two
0268-missing-number
0338-counting-bits
0342-power-of-four
0371-sum-of-two-integers
0389-find-the-difference
0461-hamming-distance
0476-number-complement
1009-complement-of-base-10-integer
1442-count-triplets-that-can-form-two-arrays-of-equal-xor
1444-number-of-steps-to-reduce-a-number-to-zero
1610-xor-operation-in-an-array
1786-count-the-number-of-consistent-strings
1835-find-xor-sum-of-all-pairs-bitwise-and
1993-sum-of-all-subset-xor-totals
2220-minimum-bit-flips-to-convert-number
2308-divide-array-into-equal-pairs
2859-sum-of-values-at-indices-with-k-set-bits
3191-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3314-construct-the-minimum-bitwise-array-i
3676-smallest-number-with-all-set-bits
3688-bitwise-or-of-even-numbers-in-an-array

Recursion

0203-remove-linked-list-elements
0231-power-of-two
0234-palindrome-linked-list
0326-power-of-three
0342-power-of-four
1013-fibonacci-number
1823-find-the-winner-of-the-circular-game

Dynamic Programming

0042-trapping-rain-water
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0070-climbing-stairs
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0124-binary-tree-maximum-path-sum
0152-maximum-product-subarray
0198-house-robber
0213-house-robber-ii
0300-longest-increasing-subsequence
0322-coin-change
0338-counting-bits
0435-non-overlapping-intervals
0646-maximum-length-of-pair-chain
1013-fibonacci-number
1641-count-sorted-vowel-strings

Memoization

0070-climbing-stairs
1013-fibonacci-number

Array

0001-two-sum
0011-container-with-most-water
0014-longest-common-prefix
0015-3sum
0018-4sum
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
0042-trapping-rain-water
0045-jump-game-ii
0046-permutations
0048-rotate-image
0049-group-anagrams
0053-maximum-subarray
0054-spiral-matrix
0055-jump-game
0056-merge-intervals
0066-plus-one
0073-set-matrix-zeroes
0075-sort-colors
0081-search-in-rotated-sorted-array-ii
0088-merge-sorted-array
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0169-majority-element
0189-rotate-array
0198-house-robber
0200-number-of-islands
0213-house-robber-ii
0228-summary-ranges
0229-majority-element-ii
0238-product-of-array-except-self
0240-search-a-2d-matrix-ii
0268-missing-number
0283-move-zeroes
0300-longest-increasing-subsequence
0322-coin-change
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0435-non-overlapping-intervals
0442-find-all-duplicates-in-an-array
0448-find-all-numbers-disappeared-in-an-array
0455-assign-cookies
0485-max-consecutive-ones
0493-reverse-pairs
0496-next-greater-element-i
0503-next-greater-element-ii
0540-single-element-in-a-sorted-array
0560-subarray-sum-equals-k
0628-maximum-product-of-three-numbers
0646-maximum-length-of-pair-chain
0654-maximum-binary-tree
0704-binary-search
0717-1-bit-and-2-bit-characters
0724-find-pivot-index
0733-flood-fill
0739-daily-temperatures
0744-find-smallest-letter-greater-than-target
0804-unique-morse-code-words
0860-lemonade-change
0875-koko-eating-bananas
0882-peak-index-in-a-mountain-array
0896-monotonic-array
0948-sort-an-array
0961-n-repeated-element-in-size-2n-array
0974-subarray-sums-divisible-by-k
0994-rotting-oranges
1019-squares-of-a-sorted-array
1168-duplicate-zeros
1200-minimum-absolute-difference
1248-count-number-of-nice-subarrays
1252-cells-with-odd-values-in-a-matrix
1256-rank-transform-of-an-array
1266-minimum-time-visiting-all-points
1304-find-n-unique-integers-sum-up-to-zero
1331-rank-transform-of-an-array
1389-create-target-array-in-the-given-order
1421-find-numbers-with-even-number-of-digits
1436-destination-city
1442-count-triplets-that-can-form-two-arrays-of-equal-xor
1482-how-many-numbers-are-smaller-than-the-current-number
1528-kids-with-the-greatest-number-of-candies
1528-shuffle-string
1548-check-if-all-1s-are-at-least-length-k-places-away
1561-maximum-number-of-coins-you-can-get
1580-shuffle-the-array
1582-special-positions-in-a-binary-matrix
1603-running-sum-of-1d-array
1635-number-of-good-pairs
1656-count-good-triplets
1665-minimum-initial-energy-to-finish-tasks
1674-minimum-moves-to-make-array-complementary
1677-matrix-diagonal-sum
1693-sum-of-all-odd-length-subarrays
1732-find-the-highest-altitude
1742-widest-vertical-area-between-two-points-containing-no-points
1748-sum-of-unique-elements
1752-check-if-array-is-sorted-and-rotated
1773-count-items-matching-a-rule
1781-check-if-two-string-arrays-are-equivalent
1786-count-the-number-of-consistent-strings
1791-richest-customer-wealth
1823-find-the-winner-of-the-circular-game
1827-minimum-operations-to-make-the-array-increasing
1833-maximum-ice-cream-bars
1835-find-xor-sum-of-all-pairs-bitwise-and
1877-minimize-maximum-pair-sum-in-array
1944-truncate-sentence
1967-number-of-strings-that-appear-as-substrings-in-word
1980-find-unique-binary-string
1984-minimum-difference-between-highest-and-lowest-of-k-scores
1993-sum-of-all-subset-xor-totals
2006-count-number-of-pairs-with-absolute-difference-k
2048-build-array-from-permutation
2058-concatenation-of-array
2102-find-the-middle-index-in-array
2106-find-greatest-common-divisor-of-array
2107-find-unique-binary-string
2126-destroying-asteroids
2132-convert-1d-array-into-2d-array
2137-final-value-of-variable-after-performing-operations
2144-minimum-cost-of-buying-candies-with-discount
2148-minimum-number-of-moves-to-seat-everyone
2149-rearrange-array-elements-by-sign
2185-counting-words-with-a-given-prefix
2210-find-target-indices-after-sorting-array
2215-finding-3-digit-even-numbers
2215-find-the-difference-of-two-arrays
2219-maximum-number-of-words-found-in-sentences
2255-count-prefixes-of-a-given-string
2274-keep-multiplying-found-values-by-two
2308-divide-array-into-equal-pairs
2357-make-array-zero-by-subtracting-equal-amounts
2367-number-of-arithmetic-triplets
2404-most-frequent-even-element
2442-count-number-of-distinct-integers-after-reverse-operations
2498-frog-jump-ii
2502-sort-the-people
2529-maximum-count-of-positive-integer-and-negative-integer
2536-determine-if-two-events-have-conflict
2540-minimum-common-value
2553-separate-the-digits-in-an-array
2566-number-of-unequal-triplets-in-array
2574-left-and-right-sum-differences
2714-left-and-right-sum-differences
2784-check-if-array-is-good
2844-sum-of-squares-of-special-elements
2847-find-maximum-number-of-string-pairs
2859-sum-of-values-at-indices-with-k-set-bits
2876-number-of-employees-who-met-the-target
2881-split-strings-by-separator
2917-count-pairs-whose-sum-is-less-than-target
2956-find-common-elements-between-two-arrays
2965-find-missing-and-repeated-values
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3074-apple-redistribution-into-boxes
3184-count-pairs-that-form-a-complete-day-i
3190-find-minimum-operations-to-make-all-elements-divisible-by-three
3191-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3194-find-words-containing-character
3226-minimum-number-game
3232-find-if-digit-game-can-be-won
3285-find-indices-of-stable-mountains
3300-minimum-element-after-replacement-with-digit-sum
3314-construct-the-minimum-bitwise-array-i
3331-minimum-operations-to-exceed-threshold-value-i
3427-sum-of-variable-length-subarrays
3429-special-array-i
3432-count-partitions-with-even-sum-difference
3446-find-the-number-of-good-pairs-i
3471-minimum-average-of-smallest-and-largest-elements
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3501-delete-nodes-from-linked-list-present-in-array
3507-minimum-pair-removal-to-sort-array-i
3550-smallest-index-with-digit-sum-equal-to-index
3555-final-array-state-after-k-multiplication-operations-i
3581-the-two-sneaky-numbers-of-digitville
3637-trionic-array-i
3688-bitwise-or-of-even-numbers-in-an-array
3689-maximum-total-subarray-value-i
3731-find-missing-elements
3736-minimum-moves-to-equal-array-elements-iii
3778-transform-array-by-parity
3838-weighted-word-mapping
3846-minimum-operations-to-make-array-sum-divisible-by-k
3867-sum-of-gcd-of-formed-pairs
3925-concatenate-array-with-reverse
4008-restore-finishing-order
4058-compute-alternating-sum

Simulation

0043-multiply-strings
0054-spiral-matrix
0067-add-binary
0412-fizz-buzz
0415-add-strings
0657-robot-return-to-origin
1252-cells-with-odd-values-in-a-matrix
1389-create-target-array-in-the-given-order
1603-design-parking-system
1806-count-of-matches-in-tournament
1823-find-the-winner-of-the-circular-game
2048-build-array-from-permutation
2058-concatenation-of-array
2076-sum-of-digits-of-string-after-convert
2132-convert-1d-array-into-2d-array
2137-final-value-of-variable-after-performing-operations
2149-rearrange-array-elements-by-sign
2180-count-integers-with-even-digit-sum
2211-count-collisions-on-a-road
2243-calculate-digit-sum-of-a-string
2274-keep-multiplying-found-values-by-two
2288-count-operations-to-obtain-zero
2357-make-array-zero-by-subtracting-equal-amounts
2553-separate-the-digits-in-an-array
2847-find-maximum-number-of-string-pairs
2886-faulty-keyboard
3174-clear-digits
3226-minimum-number-game
3507-minimum-pair-removal-to-sort-array-i
3555-final-array-state-after-k-multiplication-operations-i
3612-process-string-with-special-operations-i
3688-bitwise-or-of-even-numbers-in-an-array
3768-check-if-digits-are-equal-in-string-after-operations-i
3811-reverse-degree-of-a-string
3838-weighted-word-mapping
3867-sum-of-gcd-of-formed-pairs
3925-concatenate-array-with-reverse
4058-compute-alternating-sum

Binary Search

0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0069-sqrtx
0081-search-in-rotated-sorted-array-ii
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0222-count-complete-tree-nodes
0240-search-a-2d-matrix-ii
0268-missing-number
0300-longest-increasing-subsequence
0349-intersection-of-two-arrays
0493-reverse-pairs
0540-single-element-in-a-sorted-array
0704-binary-search
0744-find-smallest-letter-greater-than-target
0875-koko-eating-bananas
0882-peak-index-in-a-mountain-array
2210-find-target-indices-after-sorting-array
2498-frog-jump-ii
2529-maximum-count-of-positive-integer-and-negative-integer
2540-minimum-common-value
2917-count-pairs-whose-sum-is-less-than-target

Brainteaser

0292-nim-game
2481-strictly-palindromic-number

Game Theory

0292-nim-game
1561-maximum-number-of-coins-you-can-get

Two Pointers

0011-container-with-most-water
0015-3sum
0018-4sum
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0042-trapping-rain-water
0061-rotate-list
0075-sort-colors
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
0189-rotate-array
0234-palindrome-linked-list
0283-move-zeroes
0344-reverse-string
0345-reverse-vowels-of-a-string
0349-intersection-of-two-arrays
0455-assign-cookies
0953-reverse-only-letters
1019-squares-of-a-sorted-array
1168-duplicate-zeros
1455-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1877-minimize-maximum-pair-sum-in-array
2095-delete-the-middle-node-of-a-linked-list
2128-reverse-prefix-of-word
2130-maximum-twin-sum-of-a-linked-list
2149-rearrange-array-elements-by-sign
2367-number-of-arithmetic-triplets
2481-strictly-palindromic-number
2540-minimum-common-value
2917-count-pairs-whose-sum-is-less-than-target
3471-minimum-average-of-smallest-and-largest-elements
3794-reverse-string-prefix
3867-sum-of-gcd-of-formed-pairs

Stack

0042-trapping-rain-water
0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0496-next-greater-element-i
0503-next-greater-element-ii
0654-maximum-binary-tree
0739-daily-temperatures
1614-maximum-nesting-depth-of-the-parentheses
2128-reverse-prefix-of-word
2130-maximum-twin-sum-of-a-linked-list
2211-count-collisions-on-a-road
3174-clear-digits

Monotonic Stack

0042-trapping-rain-water
0496-next-greater-element-i
0503-next-greater-element-ii
0654-maximum-binary-tree
0739-daily-temperatures

Number Theory

2083-three-divisors
2106-find-greatest-common-divisor-of-array
2427-number-of-common-factors
2491-smallest-even-multiple
3768-check-if-digits-are-equal-in-string-after-operations-i
3867-sum-of-gcd-of-formed-pairs
3995-gcd-of-odd-and-even-sums

Enumeration

1656-count-good-triplets
1925-count-square-sum-triples
1993-sum-of-all-subset-xor-totals
2083-three-divisors
2215-finding-3-digit-even-numbers
2309-greatest-english-letter-in-upper-and-lower-case
2367-number-of-arithmetic-triplets
2427-number-of-common-factors
2844-sum-of-squares-of-special-elements
2998-count-symmetric-integers
3010-divide-an-array-into-subarrays-with-minimum-cost-i

Prefix Sum

0238-product-of-array-except-self
0560-subarray-sum-equals-k
0724-find-pivot-index
0974-subarray-sums-divisible-by-k
1248-count-number-of-nice-subarrays
1442-count-triplets-that-can-form-two-arrays-of-equal-xor
1603-running-sum-of-1d-array
1674-minimum-moves-to-make-array-complementary
1693-sum-of-all-odd-length-subarrays
1732-find-the-highest-altitude
2102-find-the-middle-index-in-array
2571-find-the-pivot-integer
2574-left-and-right-sum-differences
2714-left-and-right-sum-differences
3191-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3427-sum-of-variable-length-subarrays
3432-count-partitions-with-even-sum-difference

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0387-first-unique-character-in-a-string
1823-find-the-winner-of-the-circular-game
3191-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Counting

0169-majority-element
0229-majority-element-ii
0347-top-k-frequent-elements
0387-first-unique-character-in-a-string
0451-sort-characters-by-frequency
1189-maximum-number-of-balloons
1341-split-a-string-in-balanced-strings
1603-design-parking-system
1635-number-of-good-pairs
1748-sum-of-unique-elements
1786-count-the-number-of-consistent-strings
2006-count-number-of-pairs-with-absolute-difference-k
2308-divide-array-into-equal-pairs
2404-most-frequent-even-element
2442-count-number-of-distinct-integers-after-reverse-operations
2529-maximum-count-of-positive-integer-and-negative-integer
3184-count-pairs-that-form-a-complete-day-i
3438-find-valid-pair-of-adjacent-digits-in-string
3778-transform-array-by-parity

Matrix

0048-rotate-image
0054-spiral-matrix
0073-set-matrix-zeroes
0200-number-of-islands
0240-search-a-2d-matrix-ii
0733-flood-fill
0994-rotting-oranges
1582-special-positions-in-a-binary-matrix
1677-matrix-diagonal-sum
1791-richest-customer-wealth
2132-convert-1d-array-into-2d-array
2965-find-missing-and-repeated-values

Divide and Conquer

0023-merge-k-sorted-lists
0053-maximum-subarray
0148-sort-list
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits
0240-search-a-2d-matrix-ii
0347-top-k-frequent-elements
0493-reverse-pairs
0654-maximum-binary-tree
0948-sort-an-array

Greedy

0011-container-with-most-water
0045-jump-game-ii
0055-jump-game
0435-non-overlapping-intervals
0455-assign-cookies
0646-maximum-length-of-pair-chain
0860-lemonade-change
1323-maximum-69-number
1341-split-a-string-in-balanced-strings
1561-maximum-number-of-coins-you-can-get
1665-minimum-initial-energy-to-finish-tasks
1689-partitioning-into-minimum-number-of-deci-binary-numbers
1827-minimum-operations-to-make-the-array-increasing
1833-maximum-ice-cream-bars
1877-minimize-maximum-pair-sum-in-array
2126-destroying-asteroids
2144-minimum-cost-of-buying-candies-with-discount
2148-minimum-number-of-moves-to-seat-everyone
2264-minimum-sum-of-four-digit-number-after-splitting-digits
2357-make-array-zero-by-subtracting-equal-amounts
2498-frog-jump-ii
2578-split-with-minimum-sum
2864-maximum-odd-binary-number
3074-apple-redistribution-into-boxes
3689-maximum-total-subarray-value-i

Heap (Priority Queue)

0023-merge-k-sorted-lists
0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0948-sort-an-array
2357-make-array-zero-by-subtracting-equal-amounts
3226-minimum-number-game
3507-minimum-pair-removal-to-sort-array-i
3555-final-array-state-after-k-multiplication-operations-i

Backtracking

0046-permutations
1980-find-unique-binary-string
1993-sum-of-all-subset-xor-totals
2107-find-unique-binary-string

Combinatorics

1641-count-sorted-vowel-strings
1993-sum-of-all-subset-xor-totals
3768-check-if-digits-are-equal-in-string-after-operations-i

Merge Sort

0023-merge-k-sorted-lists
0148-sort-list
0493-reverse-pairs
0948-sort-an-array

Bucket Sort

0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0948-sort-an-array

Radix Sort

0948-sort-an-array

Counting Sort

0948-sort-an-array
1482-how-many-numbers-are-smaller-than-the-current-number
1833-maximum-ice-cream-bars
2148-minimum-number-of-moves-to-seat-everyone

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0200-number-of-islands
0322-coin-change
0404-sum-of-left-leaves
0513-find-bottom-left-tree-value
0547-number-of-provinces
0733-flood-fill
0783-minimum-distance-between-bst-nodes
0994-rotting-oranges
1971-find-if-path-exists-in-graph

Linked List

0023-merge-k-sorted-lists
0061-rotate-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0160-intersection-of-two-linked-lists
0203-remove-linked-list-elements
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
1290-convert-binary-number-in-a-linked-list-to-integer
2095-delete-the-middle-node-of-a-linked-list
2130-maximum-twin-sum-of-a-linked-list
3501-delete-nodes-from-linked-list-present-in-array
3507-minimum-pair-removal-to-sort-array-i

Database

0175-combine-two-tables
0176-second-highest-salary
0177-nth-highest-salary
0181-employees-earning-more-than-their-managers
0182-duplicate-emails
0183-customers-who-never-order
0184-department-highest-salary
0185-department-top-three-salaries
0196-delete-duplicate-emails
0197-rising-temperature
0511-game-play-analysis-i
0577-employee-bonus
0584-find-customer-referee
0586-customer-placing-the-largest-number-of-orders
0595-big-countries
0596-classes-with-at-least-5-students
0607-sales-person
0608-tree-node
0610-triangle-judgement
0619-biggest-single-number
0620-not-boring-movies
0626-exchange-seats
1068-product-sales-analysis-i
1075-project-employees-i
1084-sales-analysis-iii
1141-user-activity-for-the-past-30-days-i
1179-reformat-department-table
1211-queries-quality-and-percentage
1321-restaurant-growth
1633-percentage-of-users-attended-a-contest
1683-invalid-tweets
1693-daily-leads-and-partners
1741-find-total-time-spent-by-each-employee
1757-recyclable-and-low-fat-products
1795-rearrange-products-table
1907-count-salary-categories
2356-number-of-unique-subjects-taught-by-each-teacher

Design

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
1603-design-parking-system

Geometry

1266-minimum-time-visiting-all-points

Doubly-Linked List

3507-minimum-pair-removal-to-sort-array-i

Ordered Set

0493-reverse-pairs
3507-minimum-pair-removal-to-sort-array-i

Sliding Window

0003-longest-substring-without-repeating-characters
1248-count-number-of-nice-subarrays
1984-minimum-difference-between-highest-and-lowest-of-k-scores
3191-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0222-count-complete-tree-nodes
0404-sum-of-left-leaves
0513-find-bottom-left-tree-value
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
0654-maximum-binary-tree
0700-search-in-a-binary-search-tree
0783-minimum-distance-between-bst-nodes
0872-leaf-similar-trees
0938-range-sum-of-bst
2236-root-equals-sum-of-children

Depth-First Search

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0200-number-of-islands
0404-sum-of-left-leaves
0513-find-bottom-left-tree-value
0543-diameter-of-binary-tree
0547-number-of-provinces
0572-subtree-of-another-tree
0733-flood-fill
0783-minimum-distance-between-bst-nodes
0872-leaf-similar-trees
0938-range-sum-of-bst
1971-find-if-path-exists-in-graph

Binary Search Tree

0700-search-in-a-binary-search-tree
0783-minimum-distance-between-bst-nodes
0938-range-sum-of-bst

Binary Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0222-count-complete-tree-nodes
0404-sum-of-left-leaves
0513-find-bottom-left-tree-value
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
0654-maximum-binary-tree
0700-search-in-a-binary-search-tree
0783-minimum-distance-between-bst-nodes
0872-leaf-similar-trees
0938-range-sum-of-bst
2236-root-equals-sum-of-children

String Matching

0459-repeated-substring-pattern
0572-subtree-of-another-tree
0796-rotate-string
1455-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
2185-counting-words-with-a-given-prefix

Hash Function

0572-subtree-of-another-tree

Quickselect

0347-top-k-frequent-elements

Union-Find

0128-longest-consecutive-sequence
0200-number-of-islands
0547-number-of-provinces
1971-find-if-path-exists-in-graph

Graph Theory

0547-number-of-provinces
1971-find-if-path-exists-in-graph

Binary Indexed Tree

0493-reverse-pairs

Segment Tree

0493-reverse-pairs

Trie

0014-longest-common-prefix