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

LeetCode Topics

Math

0002-add-two-numbers
0062-unique-paths
0067-add-binary
0070-climbing-stairs
0168-excel-sheet-column-title
0172-factorial-trailing-zeroes
0189-rotate-array
0202-happy-number
0231-power-of-two
0263-ugly-number
0279-perfect-squares
0319-bulb-switcher
0326-power-of-three
0342-power-of-four
0415-add-strings
0441-arranging-coins
0504-base-7
0507-perfect-number
0539-minimum-time-difference
0670-maximum-swap
0866-rectangle-overlap
0944-smallest-range-i
1013-fibonacci-number
1031-add-to-array-form-of-integer
1236-n-th-tribonacci-number
1260-day-of-the-year
1426-find-n-unique-integers-sum-up-to-zero
1448-maximum-69-number
1585-the-kth-factor-of-n
1610-xor-operation-in-an-array
1630-count-odd-numbers-in-an-interval-range
1683-maximum-number-of-coins-you-can-get
1920-determine-color-of-a-chessboard-square
1993-sum-of-all-subset-xor-totals
2160-minimum-operations-to-make-a-uni-value-grid
2244-number-of-laser-beams-in-a-bank
2264-minimum-sum-of-four-digit-number-after-splitting-digits
2288-count-operations-to-obtain-zero
2298-count-integers-with-even-digit-sum
2324-find-triangular-sum-of-an-array
2645-pass-the-pillow
2715-k-items-with-the-maximum-sum
2748-calculate-delayed-arrival-time
2824-check-if-the-number-is-fascinating
2998-count-symmetric-integers
3172-divisible-and-non-divisible-sums-difference
3227-find-missing-and-repeated-values
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3515-find-if-digit-game-can-be-won
3548-find-the-count-of-good-integers
3555-final-array-state-after-k-multiplication-operations-i
3676-smallest-number-with-all-set-bits

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
0015-3sum
0033-search-in-rotated-sorted-array
0035-search-insert-position
0042-trapping-rain-water
0055-jump-game
0056-merge-intervals
0063-unique-paths-ii
0064-minimum-path-sum
0074-search-a-2d-matrix
0118-pascals-triangle
0119-pascals-triangle-ii
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0130-surrounded-regions
0139-word-break
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0189-rotate-array
0198-house-robber
0200-number-of-islands
0215-kth-largest-element-in-an-array
0219-contains-duplicate-ii
0238-product-of-array-except-self
0260-single-number-iii
0287-find-the-duplicate-number
0347-top-k-frequent-elements
0350-intersection-of-two-arrays-ii
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0448-find-all-numbers-disappeared-in-an-array
0485-max-consecutive-ones
0506-relative-ranks
0539-minimum-time-difference
0561-array-partition
0594-longest-harmonious-subsequence
0645-set-mismatch
0648-replace-words
0682-baseball-game
0718-maximum-length-of-repeated-subarray
0724-find-pivot-index
0747-min-cost-climbing-stairs
0932-monotonic-array
0940-fruit-into-baskets
0941-sort-array-by-parity
0944-smallest-range-i
0958-sort-array-by-parity-ii
0979-di-string-match
1031-add-to-array-form-of-integer
1071-binary-prefix-divisible-by-5
1127-last-stone-weight
1171-shortest-path-in-binary-matrix
1217-relative-sort-array
1227-number-of-equivalent-domino-pairs
1256-rank-transform-of-an-array
1293-three-consecutive-odds
1310-watering-plants
1408-find-the-smallest-divisor-given-a-threshold
1426-find-n-unique-integers-sum-up-to-zero
1482-how-many-numbers-are-smaller-than-the-current-number
1505-create-target-array-in-the-given-order
1524-string-matching-in-an-array
1683-maximum-number-of-coins-you-can-get
1711-find-valid-matrix-given-row-and-column-sums
1786-count-the-number-of-consistent-strings
1803-average-waiting-time
1878-check-if-array-is-sorted-and-rotated
1938-minimum-operations-to-make-the-array-increasing
1961-maximum-ice-cream-bars
1993-sum-of-all-subset-xor-totals
2048-build-array-from-permutation
2093-check-if-string-is-a-prefix-of-array
2116-count-number-of-pairs-with-absolute-difference-k
2133-number-of-pairs-of-strings-with-concatenation-equal-to-target
2159-two-out-of-three
2160-minimum-operations-to-make-a-uni-value-grid
2163-kth-distinct-string-in-an-array
2210-find-target-indices-after-sorting-array
2215-finding-3-digit-even-numbers
2244-number-of-laser-beams-in-a-bank
2254-check-if-every-row-and-column-contains-all-numbers
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2277-count-equal-and-divisible-pairs-in-an-array
2292-counting-words-with-a-given-prefix
2308-divide-array-into-equal-pairs
2324-find-triangular-sum-of-an-array
2341-count-prefixes-of-a-given-string
2358-number-of-ways-to-split-array
2428-equal-row-and-column-pairs
2551-apply-operations-to-an-array
2561-number-of-distinct-averages
2581-divide-players-into-teams-of-equal-skill
2589-maximum-value-of-a-string-in-an-array
2594-count-pairs-of-similar-strings
2626-count-the-number-of-good-subarrays
2631-sort-the-students-by-their-kth-score
2634-minimum-common-value
2665-minimum-time-to-repair-cars
2691-count-vowel-strings-in-ranges
2707-merge-two-2d-arrays-by-summing-values
2720-minimize-the-maximum-difference-of-pairs
2856-count-complete-subarrays-in-an-array
2881-split-strings-by-separator
2977-check-if-a-string-is-an-acronym-of-words
3093-sum-of-values-at-indices-with-k-set-bits
3152-maximum-value-of-an-ordered-triplet-ii
3154-maximum-value-of-an-ordered-triplet-i
3165-find-indices-with-index-and-value-difference-i
3227-find-missing-and-repeated-values
3242-count-elements-with-maximum-frequency
3246-check-if-bitwise-or-has-trailing-zeros
3309-count-prefix-and-suffix-pairs-i
3331-minimum-operations-to-exceed-threshold-value-i
3429-special-array-i
3463-alternating-groups-i
3471-minimum-average-of-smallest-and-largest-elements
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3501-delete-nodes-from-linked-list-present-in-array
3515-find-if-digit-game-can-be-won
3555-final-array-state-after-k-multiplication-operations-i
3656-minimum-number-of-operations-to-make-elements-in-array-distinct

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0139-word-break
0202-happy-number
0205-isomorphic-strings
0219-contains-duplicate-ii
0242-valid-anagram
0347-top-k-frequent-elements
0350-intersection-of-two-arrays-ii
0383-ransom-note
0387-first-unique-character-in-a-string
0448-find-all-numbers-disappeared-in-an-array
0451-sort-characters-by-frequency
0594-longest-harmonious-subsequence
0645-set-mismatch
0648-replace-words
0768-partition-labels
0920-uncommon-words-from-two-sentences
0940-fruit-into-baskets
1217-relative-sort-array
1227-number-of-equivalent-domino-pairs
1256-rank-transform-of-an-array
1482-how-many-numbers-are-smaller-than-the-current-number
1502-construct-k-palindrome-strings
1786-count-the-number-of-consistent-strings
1987-substrings-of-size-three-with-distinct-characters
2053-check-if-all-characters-have-equal-number-of-occurrences
2116-count-number-of-pairs-with-absolute-difference-k
2133-number-of-pairs-of-strings-with-concatenation-equal-to-target
2159-two-out-of-three
2163-kth-distinct-string-in-an-array
2177-check-whether-two-strings-are-almost-equivalent
2215-finding-3-digit-even-numbers
2254-check-if-every-row-and-column-contains-all-numbers
2308-divide-array-into-equal-pairs
2427-first-letter-to-appear-twice
2428-equal-row-and-column-pairs
2487-optimal-partition-of-string
2561-number-of-distinct-averages
2581-divide-players-into-teams-of-equal-skill
2594-count-pairs-of-similar-strings
2626-count-the-number-of-good-subarrays
2634-minimum-common-value
2707-merge-two-2d-arrays-by-summing-values
2824-check-if-the-number-is-fascinating
2825-minimize-string-length
2856-count-complete-subarrays-in-an-array
3227-find-missing-and-repeated-values
3242-count-elements-with-maximum-frequency
3447-clear-digits
3501-delete-nodes-from-linked-list-present-in-array
3548-find-the-count-of-good-integers
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3753-maximum-difference-between-even-and-odd-frequency-i

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0019-remove-nth-node-from-end-of-list
0042-trapping-rain-water
0061-rotate-list
0125-valid-palindrome
0189-rotate-array
0202-happy-number
0287-find-the-duplicate-number
0345-reverse-vowels-of-a-string
0350-intersection-of-two-arrays-ii
0392-is-subsequence
0541-reverse-string-ii
0557-reverse-words-in-a-string-iii
0768-partition-labels
0874-backspace-string-compare
0941-sort-array-by-parity
0958-sort-array-by-parity-ii
0979-di-string-match
2093-check-if-string-is-a-prefix-of-array
2095-minimum-number-of-swaps-to-make-the-string-balanced
2128-reverse-prefix-of-word
2236-maximum-twin-sum-of-a-linked-list
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2551-apply-operations-to-an-array
2561-number-of-distinct-averages
2581-divide-players-into-teams-of-equal-skill
2634-minimum-common-value
2707-merge-two-2d-arrays-by-summing-values
3165-find-indices-with-index-and-value-difference-i
3471-minimum-average-of-smallest-and-largest-elements

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0035-search-insert-position
0074-search-a-2d-matrix
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0287-find-the-duplicate-number
0350-intersection-of-two-arrays-ii
0374-guess-number-higher-or-lower
0441-arranging-coins
0718-maximum-length-of-repeated-subarray
1408-find-the-smallest-divisor-given-a-threshold
2210-find-target-indices-after-sorting-array
2634-minimum-common-value
2665-minimum-time-to-repair-cars
2720-minimize-the-maximum-difference-of-pairs

Sorting

0015-3sum
0056-merge-intervals
0215-kth-largest-element-in-an-array
0242-valid-anagram
0347-top-k-frequent-elements
0350-intersection-of-two-arrays-ii
0435-non-overlapping-intervals
0451-sort-characters-by-frequency
0506-relative-ranks
0539-minimum-time-difference
0561-array-partition
0594-longest-harmonious-subsequence
0645-set-mismatch
0941-sort-array-by-parity
0958-sort-array-by-parity-ii
1217-relative-sort-array
1256-rank-transform-of-an-array
1482-how-many-numbers-are-smaller-than-the-current-number
1683-maximum-number-of-coins-you-can-get
1961-maximum-ice-cream-bars
1970-sorting-the-sentence
2160-minimum-operations-to-make-a-uni-value-grid
2210-find-target-indices-after-sorting-array
2215-finding-3-digit-even-numbers
2264-minimum-sum-of-four-digit-number-after-splitting-digits
2561-number-of-distinct-averages
2581-divide-players-into-teams-of-equal-skill
2631-sort-the-students-by-their-kth-score
3471-minimum-average-of-smallest-and-largest-elements

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0006-zigzag-conversion
0014-longest-common-prefix
0020-valid-parentheses
0032-longest-valid-parentheses
0067-add-binary
0125-valid-palindrome
0139-word-break
0168-excel-sheet-column-title
0205-isomorphic-strings
0242-valid-anagram
0345-reverse-vowels-of-a-string
0383-ransom-note
0387-first-unique-character-in-a-string
0392-is-subsequence
0415-add-strings
0451-sort-characters-by-frequency
0459-repeated-substring-pattern
0520-detect-capital
0539-minimum-time-difference
0541-reverse-string-ii
0557-reverse-words-in-a-string-iii
0648-replace-words
0768-partition-labels
0874-backspace-string-compare
0920-uncommon-words-from-two-sentences
0979-di-string-match
1058-lexicographically-smallest-equivalent-string
1260-day-of-the-year
1502-construct-k-palindrome-strings
1524-string-matching-in-an-array
1537-maximum-score-after-splitting-a-string
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1737-maximum-nesting-depth-of-the-parentheses
1786-count-the-number-of-consistent-strings
1823-determine-if-string-halves-are-alike
1920-determine-color-of-a-chessboard-square
1954-replace-all-digits-with-characters
1967-longest-substring-of-all-vowels-in-order
1970-sorting-the-sentence
1987-substrings-of-size-three-with-distinct-characters
2053-check-if-all-characters-have-equal-number-of-occurrences
2076-sum-of-digits-of-string-after-convert
2088-minimum-time-to-type-word-using-special-typewriter
2093-check-if-string-is-a-prefix-of-array
2095-minimum-number-of-swaps-to-make-the-string-balanced
2099-number-of-strings-that-appear-as-substrings-in-word
2128-reverse-prefix-of-word
2133-number-of-pairs-of-strings-with-concatenation-equal-to-target
2163-kth-distinct-string-in-an-array
2168-check-if-numbers-are-ascending-in-a-sentence
2177-check-whether-two-strings-are-almost-equivalent
2244-number-of-laser-beams-in-a-bank
2260-divide-a-string-into-groups-of-size-k
2292-counting-words-with-a-given-prefix
2341-count-prefixes-of-a-given-string
2365-percentage-of-letter-in-string
2427-first-letter-to-appear-twice
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2470-removing-stars-from-a-string
2487-optimal-partition-of-string
2589-maximum-value-of-a-string-in-an-array
2594-count-pairs-of-similar-strings
2691-count-vowel-strings-in-ranges
2819-remove-trailing-zeros-from-a-string
2825-minimize-string-length
2881-split-strings-by-separator
2886-faulty-keyboard
2977-check-if-a-string-is-an-acronym-of-words
3309-count-prefix-and-suffix-pairs-i
3312-number-of-changing-keys
3447-clear-digits
3753-maximum-difference-between-even-and-odd-frequency-i

Counting

0347-top-k-frequent-elements
0383-ransom-note
0387-first-unique-character-in-a-string
0451-sort-characters-by-frequency
0594-longest-harmonious-subsequence
0920-uncommon-words-from-two-sentences
1227-number-of-equivalent-domino-pairs
1502-construct-k-palindrome-strings
1786-count-the-number-of-consistent-strings
1823-determine-if-string-halves-are-alike
1987-substrings-of-size-three-with-distinct-characters
2053-check-if-all-characters-have-equal-number-of-occurrences
2116-count-number-of-pairs-with-absolute-difference-k
2133-number-of-pairs-of-strings-with-concatenation-equal-to-target
2163-kth-distinct-string-in-an-array
2177-check-whether-two-strings-are-almost-equivalent
2308-divide-array-into-equal-pairs
2427-first-letter-to-appear-twice
2594-count-pairs-of-similar-strings
3242-count-elements-with-maximum-frequency
3753-maximum-difference-between-even-and-odd-frequency-i

Divide and Conquer

0004-median-of-two-sorted-arrays
0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements

Simulation

0067-add-binary
0415-add-strings
0682-baseball-game
0874-backspace-string-compare
1310-watering-plants
1505-create-target-array-in-the-given-order
1803-average-waiting-time
2048-build-array-from-permutation
2076-sum-of-digits-of-string-after-convert
2260-divide-a-string-into-groups-of-size-k
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2288-count-operations-to-obtain-zero
2298-count-integers-with-even-digit-sum
2324-find-triangular-sum-of-an-array
2428-equal-row-and-column-pairs
2470-removing-stars-from-a-string
2551-apply-operations-to-an-array
2645-pass-the-pillow
2886-faulty-keyboard
3447-clear-digits
3555-final-array-state-after-k-multiplication-operations-i

String Matching

0459-repeated-substring-pattern
1524-string-matching-in-an-array
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i

Stack

0020-valid-parentheses
0032-longest-valid-parentheses
0042-trapping-rain-water
0682-baseball-game
0874-backspace-string-compare
1737-maximum-nesting-depth-of-the-parentheses
2095-minimum-number-of-swaps-to-make-the-string-balanced
2236-maximum-twin-sum-of-a-linked-list
2470-removing-stars-from-a-string

Bit Manipulation

0067-add-binary
0231-power-of-two
0260-single-number-iii
0287-find-the-duplicate-number
0338-counting-bits
0342-power-of-four
0645-set-mismatch
1054-complement-of-base-10-integer
1071-binary-prefix-divisible-by-5
1610-xor-operation-in-an-array
1786-count-the-number-of-consistent-strings
1993-sum-of-all-subset-xor-totals
2159-two-out-of-three
2308-divide-array-into-equal-pairs
2427-first-letter-to-appear-twice
2594-count-pairs-of-similar-strings
2659-number-of-even-and-odd-bits
3093-sum-of-values-at-indices-with-k-set-bits
3246-check-if-bitwise-or-has-trailing-zeros
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3676-smallest-number-with-all-set-bits

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0506-relative-ranks
1127-last-stone-weight
3555-final-array-state-after-k-multiplication-operations-i

Bucket Sort

0347-top-k-frequent-elements
0451-sort-characters-by-frequency

Database

0181-employees-earning-more-than-their-managers
0182-duplicate-emails
0196-delete-duplicate-emails
0197-rising-temperature
0570-managers-with-at-least-5-direct-reports
0577-employee-bonus
0584-find-customer-referee
0586-customer-placing-the-largest-number-of-orders
0607-sales-person
0620-not-boring-movies
0627-swap-salary
1153-product-sales-analysis-i
1390-average-selling-price
1415-students-and-examinations
1509-replace-employee-id-with-the-unique-identifier
1523-capital-gainloss
1664-find-users-with-valid-e-mails
1724-customer-who-visited-but-did-not-make-any-transactions
2087-confirmation-rate

Matrix

0063-unique-paths-ii
0064-minimum-path-sum
0074-search-a-2d-matrix
0130-surrounded-regions
0200-number-of-islands
1171-shortest-path-in-binary-matrix
1711-find-valid-matrix-given-row-and-column-sums
2160-minimum-operations-to-make-a-uni-value-grid
2244-number-of-laser-beams-in-a-bank
2254-check-if-every-row-and-column-contains-all-numbers
2428-equal-row-and-column-pairs
2631-sort-the-students-by-their-kth-score
3227-find-missing-and-repeated-values

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0061-rotate-list
0206-reverse-linked-list
0237-delete-node-in-a-linked-list
2236-maximum-twin-sum-of-a-linked-list
3501-delete-nodes-from-linked-list-present-in-array

Queue

0387-first-unique-character-in-a-string
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Recursion

0002-add-two-numbers
0206-reverse-linked-list
0231-power-of-two
0326-power-of-three
0342-power-of-four
1013-fibonacci-number

Trie

0014-longest-common-prefix
0139-word-break
0648-replace-words
3309-count-prefix-and-suffix-pairs-i

Geometry

0866-rectangle-overlap

Number Theory

1585-the-kth-factor-of-n

Dynamic Programming

0005-longest-palindromic-substring
0032-longest-valid-parentheses
0042-trapping-rain-water
0055-jump-game
0062-unique-paths
0063-unique-paths-ii
0064-minimum-path-sum
0070-climbing-stairs
0118-pascals-triangle
0119-pascals-triangle-ii
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0139-word-break
0198-house-robber
0279-perfect-squares
0338-counting-bits
0392-is-subsequence
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0718-maximum-length-of-repeated-subarray
0747-min-cost-climbing-stairs
1013-fibonacci-number
1236-n-th-tribonacci-number

Memoization

0070-climbing-stairs
0139-word-break
1013-fibonacci-number
1236-n-th-tribonacci-number

Counting Sort

0561-array-partition
1217-relative-sort-array
1482-how-many-numbers-are-smaller-than-the-current-number

Greedy

0011-container-with-most-water
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0435-non-overlapping-intervals
0561-array-partition
0670-maximum-swap
0768-partition-labels
0979-di-string-match
1448-maximum-69-number
1502-construct-k-palindrome-strings
1683-maximum-number-of-coins-you-can-get
1711-find-valid-matrix-given-row-and-column-sums
1938-minimum-operations-to-make-the-array-increasing
1961-maximum-ice-cream-bars
2088-minimum-time-to-type-word-using-special-typewriter
2095-minimum-number-of-swaps-to-make-the-string-balanced
2264-minimum-sum-of-four-digit-number-after-splitting-digits
2487-optimal-partition-of-string
2715-k-items-with-the-maximum-sum
2720-minimize-the-maximum-difference-of-pairs

Game Theory

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

Interactive

0374-guess-number-higher-or-lower

Quickselect

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

Breadth-First Search

0130-surrounded-regions
0200-number-of-islands
0279-perfect-squares
1171-shortest-path-in-binary-matrix

Prefix Sum

0238-product-of-array-except-self
0724-find-pivot-index
1537-maximum-score-after-splitting-a-string
2358-number-of-ways-to-split-array
2691-count-vowel-strings-in-ranges
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Rolling Hash

0718-maximum-length-of-repeated-subarray
3309-count-prefix-and-suffix-pairs-i

Hash Function

0718-maximum-length-of-repeated-subarray
3309-count-prefix-and-suffix-pairs-i

Sliding Window

0003-longest-substring-without-repeating-characters
0219-contains-duplicate-ii
0594-longest-harmonious-subsequence
0718-maximum-length-of-repeated-subarray
0940-fruit-into-baskets
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1967-longest-substring-of-all-vowels-in-order
1987-substrings-of-size-three-with-distinct-characters
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2626-count-the-number-of-good-subarrays
2856-count-complete-subarrays-in-an-array
3463-alternating-groups-i
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Depth-First Search

0130-surrounded-regions
0200-number-of-islands

Union Find

0130-surrounded-regions
0200-number-of-islands
1058-lexicographically-smallest-equivalent-string

Brainteaser

0319-bulb-switcher

Combinatorics

0062-unique-paths
1993-sum-of-all-subset-xor-totals
2324-find-triangular-sum-of-an-array
3548-find-the-count-of-good-integers

Backtracking

1993-sum-of-all-subset-xor-totals

Enumeration

1993-sum-of-all-subset-xor-totals
2215-finding-3-digit-even-numbers
2998-count-symmetric-integers
3548-find-the-count-of-good-integers

Monotonic Stack

0042-trapping-rain-water