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

LeetCode Topics

Array

0001-two-sum
0039-combination-sum
0078-subsets
0217-contains-duplicate
0283-move-zeroes
0303-range-sum-query-immutable
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0407-trapping-rain-water-ii
0414-third-maximum-number
0463-island-perimeter
0561-array-partition
0822-unique-morse-code-words
0861-flipping-an-image
0890-lemonade-change
0952-word-subsets
1001-n-repeated-element-in-size-2n-array
1044-find-common-characters
1137-height-checker
1392-find-the-difference-of-two-arrays
1407-group-the-people-given-the-group-size-they-belong-to
1426-find-n-unique-integers-sum-up-to-zero
1458-sort-integers-by-the-number-of-1-bits
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1505-create-target-array-in-the-given-order
1524-string-matching-in-an-array
1528-kids-with-the-greatest-number-of-candies
1547-destination-city
1556-make-two-arrays-equal-by-reversing-subarrays
1570-final-prices-with-a-special-discount-in-a-shop
1572-subrectangle-queries
1574-maximum-product-of-two-elements-in-an-array
1580-shuffle-the-array
1635-number-of-good-pairs
1656-count-good-triplets
1683-maximum-number-of-coins-you-can-get
1693-sum-of-all-odd-length-subarrays
1741-sort-array-by-increasing-frequency
1755-defuse-the-bomb
1781-check-if-two-string-arrays-are-equivalent
1786-count-the-number-of-consistent-strings
1791-richest-customer-wealth
1833-find-the-highest-altitude
1843-number-of-rectangles-that-can-form-the-largest-square
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1899-count-items-matching-a-rule
1938-minimum-operations-to-make-the-array-increasing
1944-truncate-sentence
1972-rotating-the-box
1988-minimize-maximum-pair-sum-in-array
2048-build-array-from-permutation
2058-concatenation-of-array
2099-number-of-strings-that-appear-as-substrings-in-word
2116-count-number-of-pairs-with-absolute-difference-k
2137-final-value-of-variable-after-performing-operations
2148-minimum-number-of-moves-to-seat-everyone
2163-kth-distinct-string-in-an-array
2195-time-needed-to-buy-tickets
2219-maximum-number-of-words-found-in-sentences
2244-number-of-laser-beams-in-a-bank
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2292-counting-words-with-a-given-prefix
2358-number-of-ways-to-split-array
2442-number-of-arithmetic-triplets
2465-shifting-letters-ii
2502-sort-the-people
2519-find-the-original-array-of-prefix-xor
2525-count-number-of-distinct-integers-after-reverse-operations
2533-bitwise-xor-of-all-pairings
2566-number-of-unequal-triplets-in-array
2624-difference-between-element-sum-and-digit-sum-of-an-array
2639-separate-the-digits-in-an-array
2691-count-vowel-strings-in-ranges
2714-left-and-right-sum-differences
2724-convert-an-array-into-a-2d-array-with-conditions
2767-maximum-sum-with-exactly-k-elements
2792-neighboring-bitwise-xor
2844-sum-of-squares-of-special-elements
2847-find-maximum-number-of-string-pairs
2876-number-of-employees-who-met-the-target
2917-count-pairs-whose-sum-is-less-than-target
2977-check-if-a-string-is-an-acronym-of-words
3163-subarrays-distinct-element-sum-of-squares-i
3194-find-words-containing-character
3206-find-common-elements-between-two-arrays
3226-minimum-number-game
3249-minimum-number-of-operations-to-make-array-xor-equal-to-k
3309-count-prefix-and-suffix-pairs-i
3331-minimum-operations-to-exceed-threshold-value-i
3397-find-the-integer-added-to-array-i
3420-find-occurrences-of-an-element-in-an-array
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
3556-final-array-state-after-k-multiplication-operations-ii
3581-the-two-sneaky-numbers-of-digitville
3613-maximize-amount-after-two-days-of-conversions
3686-count-beautiful-splits-in-an-array

Simulation

0258-add-digits
0412-fizz-buzz
0657-robot-return-to-origin
0861-flipping-an-image
1505-create-target-array-in-the-given-order
1708-design-parking-system
2048-build-array-from-permutation
2058-concatenation-of-array
2137-final-value-of-variable-after-performing-operations
2195-time-needed-to-buy-tickets
2239-execution-of-all-suffix-instructions-staying-in-a-grid
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2639-separate-the-digits-in-an-array
2800-minimum-string-length-after-removing-substrings
2847-find-maximum-number-of-string-pairs
2886-faulty-keyboard
3226-minimum-number-game
3556-final-array-state-after-k-multiplication-operations-ii

Math

0258-add-digits
0412-fizz-buzz
1426-find-n-unique-integers-sum-up-to-zero
1635-number-of-good-pairs
1683-maximum-number-of-coins-you-can-get
1693-sum-of-all-odd-length-subarrays
2244-number-of-laser-beams-in-a-bank
2525-count-number-of-distinct-integers-after-reverse-operations
2556-convert-the-temperature
2624-difference-between-element-sum-and-digit-sum-of-an-array
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3581-the-two-sneaky-numbers-of-digitville

String

0005-longest-palindromic-substring
0020-valid-parentheses
0022-generate-parentheses
0205-isomorphic-strings
0290-word-pattern
0344-reverse-string
0392-is-subsequence
0409-longest-palindrome
0412-fizz-buzz
0535-encode-and-decode-tinyurl
0657-robot-return-to-origin
0742-to-lower-case
0782-jewels-and-stones
0822-unique-morse-code-words
0952-word-subsets
1044-find-common-characters
1078-remove-outermost-parentheses
1160-letter-tile-possibilities
1205-defanging-an-ip-address
1341-split-a-string-in-balanced-strings
1469-minimum-number-of-steps-to-make-two-strings-anagram
1502-construct-k-palindrome-strings
1524-string-matching-in-an-array
1537-maximum-score-after-splitting-a-string
1547-destination-city
1737-maximum-nesting-depth-of-the-parentheses
1781-check-if-two-string-arrays-are-equivalent
1786-count-the-number-of-consistent-strings
1797-goal-parser-interpretation
1807-partitioning-into-minimum-number-of-deci-binary-numbers
1894-merge-strings-alternately
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1899-count-items-matching-a-rule
1915-check-if-one-string-swap-can-make-strings-equal
1944-truncate-sentence
1954-replace-all-digits-with-characters
2010-check-if-word-equals-summation-of-two-words
2099-number-of-strings-that-appear-as-substrings-in-word
2128-reverse-prefix-of-word
2137-final-value-of-variable-after-performing-operations
2163-kth-distinct-string-in-an-array
2219-maximum-number-of-words-found-in-sentences
2221-check-if-a-parentheses-string-can-be-valid
2226-rings-and-rods
2239-execution-of-all-suffix-instructions-staying-in-a-grid
2244-number-of-laser-beams-in-a-bank
2292-counting-words-with-a-given-prefix
2401-count-asterisks
2406-decode-the-message
2465-shifting-letters-ii
2502-sort-the-people
2691-count-vowel-strings-in-ranges
2800-minimum-string-length-after-removing-substrings
2847-find-maximum-number-of-string-pairs
2886-faulty-keyboard
2977-check-if-a-string-is-an-acronym-of-words
3194-find-words-containing-character
3309-count-prefix-and-suffix-pairs-i
3312-number-of-changing-keys
3379-score-of-a-string
3396-valid-word
3412-permutation-difference-between-two-strings
3453-generate-binary-strings-without-adjacent-zeros
3455-minimum-length-of-string-after-operations
3580-find-the-occurrence-of-first-almost-equal-substring
3613-maximize-amount-after-two-days-of-conversions

Hash Table

0001-two-sum
0205-isomorphic-strings
0217-contains-duplicate
0290-word-pattern
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0409-longest-palindrome
0535-encode-and-decode-tinyurl
0782-jewels-and-stones
0822-unique-morse-code-words
0952-word-subsets
1001-n-repeated-element-in-size-2n-array
1044-find-common-characters
1160-letter-tile-possibilities
1392-find-the-difference-of-two-arrays
1407-group-the-people-given-the-group-size-they-belong-to
1469-minimum-number-of-steps-to-make-two-strings-anagram
1502-construct-k-palindrome-strings
1547-destination-city
1556-make-two-arrays-equal-by-reversing-subarrays
1635-number-of-good-pairs
1741-sort-array-by-increasing-frequency
1786-count-the-number-of-consistent-strings
1915-check-if-one-string-swap-can-make-strings-equal
2116-count-number-of-pairs-with-absolute-difference-k
2163-kth-distinct-string-in-an-array
2226-rings-and-rods
2406-decode-the-message
2442-number-of-arithmetic-triplets
2502-sort-the-people
2525-count-number-of-distinct-integers-after-reverse-operations
2566-number-of-unequal-triplets-in-array
2724-convert-an-array-into-a-2d-array-with-conditions
2847-find-maximum-number-of-string-pairs
3163-subarrays-distinct-element-sum-of-squares-i
3206-find-common-elements-between-two-arrays
3412-permutation-difference-between-two-strings
3420-find-occurrences-of-an-element-in-an-array
3446-find-the-number-of-good-pairs-i
3455-minimum-length-of-string-after-operations
3581-the-two-sneaky-numbers-of-digitville

Counting

1160-letter-tile-possibilities
1341-split-a-string-in-balanced-strings
1458-sort-integers-by-the-number-of-1-bits
1469-minimum-number-of-steps-to-make-two-strings-anagram
1502-construct-k-palindrome-strings
1635-number-of-good-pairs
1708-design-parking-system
1786-count-the-number-of-consistent-strings
1915-check-if-one-string-swap-can-make-strings-equal
2116-count-number-of-pairs-with-absolute-difference-k
2163-kth-distinct-string-in-an-array
2525-count-number-of-distinct-integers-after-reverse-operations
3455-minimum-length-of-string-after-operations

Stack

0020-valid-parentheses
1078-remove-outermost-parentheses
1570-final-prices-with-a-special-discount-in-a-shop
1737-maximum-nesting-depth-of-the-parentheses
2128-reverse-prefix-of-word
2221-check-if-a-parentheses-string-can-be-valid
2800-minimum-string-length-after-removing-substrings

Two Pointers

0005-longest-palindromic-substring
0283-move-zeroes
0344-reverse-string
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0392-is-subsequence
0861-flipping-an-image
1894-merge-strings-alternately
1972-rotating-the-box
1988-minimize-maximum-pair-sum-in-array
2128-reverse-prefix-of-word
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2442-number-of-arithmetic-triplets
2917-count-pairs-whose-sum-is-less-than-target
3471-minimum-average-of-smallest-and-largest-elements

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0392-is-subsequence
3686-count-beautiful-splits-in-an-array

Greedy

0409-longest-palindrome
0561-array-partition
0890-lemonade-change
1341-split-a-string-in-balanced-strings
1407-group-the-people-given-the-group-size-they-belong-to
1502-construct-k-palindrome-strings
1683-maximum-number-of-coins-you-can-get
1807-partitioning-into-minimum-number-of-deci-binary-numbers
1938-minimum-operations-to-make-the-array-increasing
1988-minimize-maximum-pair-sum-in-array
2148-minimum-number-of-moves-to-seat-everyone
2221-check-if-a-parentheses-string-can-be-valid
2509-minimize-xor
2767-maximum-sum-with-exactly-k-elements

Backtracking

0022-generate-parentheses
0039-combination-sum
0078-subsets
1160-letter-tile-possibilities
3453-generate-binary-strings-without-adjacent-zeros

Design

0303-range-sum-query-immutable
0535-encode-and-decode-tinyurl
1572-subrectangle-queries
1708-design-parking-system

Prefix Sum

0303-range-sum-query-immutable
1537-maximum-score-after-splitting-a-string
1693-sum-of-all-odd-length-subarrays
1833-find-the-highest-altitude
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
2358-number-of-ways-to-split-array
2465-shifting-letters-ii
2691-count-vowel-strings-in-ranges
2714-left-and-right-sum-differences

Binary Search

0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
2917-count-pairs-whose-sum-is-less-than-target

Sorting

0217-contains-duplicate
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0414-third-maximum-number
0561-array-partition
1137-height-checker
1458-sort-integers-by-the-number-of-1-bits
1556-make-two-arrays-equal-by-reversing-subarrays
1574-maximum-product-of-two-elements-in-an-array
1683-maximum-number-of-coins-you-can-get
1741-sort-array-by-increasing-frequency
1988-minimize-maximum-pair-sum-in-array
2148-minimum-number-of-moves-to-seat-everyone
2502-sort-the-people
2566-number-of-unequal-triplets-in-array
2917-count-pairs-whose-sum-is-less-than-target
3226-minimum-number-game
3471-minimum-average-of-smallest-and-largest-elements

Counting Sort

0561-array-partition
1137-height-checker
2148-minimum-number-of-moves-to-seat-everyone

Matrix

0407-trapping-rain-water-ii
0463-island-perimeter
0861-flipping-an-image
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1572-subrectangle-queries
1791-richest-customer-wealth
1972-rotating-the-box
2244-number-of-laser-beams-in-a-bank

Monotonic Stack

1570-final-prices-with-a-special-discount-in-a-shop

Depth-First Search

0463-island-perimeter
3613-maximize-amount-after-two-days-of-conversions

Breadth-First Search

0407-trapping-rain-water-ii
0463-island-perimeter
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
3613-maximize-amount-after-two-days-of-conversions

Graph

1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
3613-maximize-amount-after-two-days-of-conversions

Bit Manipulation

0078-subsets
0861-flipping-an-image
1458-sort-integers-by-the-number-of-1-bits
1786-count-the-number-of-consistent-strings
2509-minimize-xor
2519-find-the-original-array-of-prefix-xor
2533-bitwise-xor-of-all-pairings
2792-neighboring-bitwise-xor
3249-minimum-number-of-operations-to-make-array-xor-equal-to-k
3453-generate-binary-strings-without-adjacent-zeros

Hash Function

0535-encode-and-decode-tinyurl
3309-count-prefix-and-suffix-pairs-i

String Matching

1524-string-matching-in-an-array
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i
3580-find-the-occurrence-of-first-almost-equal-substring

Heap (Priority Queue)

0407-trapping-rain-water-ii
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1574-maximum-product-of-two-elements-in-an-array
3226-minimum-number-game
3556-final-array-state-after-k-multiplication-operations-ii

Trie

3309-count-prefix-and-suffix-pairs-i

Rolling Hash

3309-count-prefix-and-suffix-pairs-i

Enumeration

1656-count-good-triplets
2442-number-of-arithmetic-triplets
2844-sum-of-squares-of-special-elements

Game Theory

1683-maximum-number-of-coins-you-can-get

Number Theory

0258-add-digits

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
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

Brainteaser

2533-bitwise-xor-of-all-pairings

Shortest Path

1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid

Sliding Window

1755-defuse-the-bomb

Queue

2195-time-needed-to-buy-tickets