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

LeetCode Topics

Array

0001-two-sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0041-first-missing-positive
0049-group-anagrams
0053-maximum-subarray
0054-spiral-matrix
0066-plus-one
0073-set-matrix-zeroes
0075-sort-colors
0088-merge-sorted-array
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0149-max-points-on-a-line
0152-maximum-product-subarray
0169-majority-element
0204-count-primes
0217-contains-duplicate
0347-top-k-frequent-elements
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0496-next-greater-element-i
0594-longest-harmonious-subsequence
0682-baseball-game
0797-rabbits-in-forest
0934-bitwise-ors-of-subarrays
1049-minimum-domino-rotations-for-equal-row
1095-two-city-scheduling
1293-three-consecutive-odds
1421-find-numbers-with-even-number-of-digits
1424-maximum-candies-you-can-get-from-boxes
1478-maximum-number-of-events-that-can-be-attended
1510-find-lucky-integer-in-an-array
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1656-count-good-triplets
1813-maximum-erasure-value
1851-maximum-number-of-events-that-can-be-attended-ii
1993-sum-of-all-subset-xor-totals
2048-build-array-from-permutation
2123-the-number-of-weak-characters-in-the-game
2170-count-number-of-maximum-bitwise-or-subsets
2180-maximum-number-of-tasks-you-can-assign
2215-finding-3-digit-even-numbers
2229-maximum-fruits-harvested-after-at-most-k-steps
2237-longest-palindrome-by-concatenating-two-letter-words
2267-minimum-difference-in-sums-after-removal-of-elements
2271-rearrange-array-elements-by-sign
2277-count-equal-and-divisible-pairs-in-an-array
2280-count-good-triplets-in-an-array
2316-count-hills-and-valleys-in-an-array
2320-find-all-k-distant-indices-in-an-array
2387-partition-array-such-that-maximum-difference-is-k
2394-count-subarrays-with-score-less-than-k
2400-minimum-score-after-removals-on-a-tree
2479-meeting-rooms-iii
2497-maximum-matching-of-players-with-trainers
2498-smallest-subarrays-with-maximum-bitwise-or
2503-longest-subarray-with-maximum-bitwise-and
2527-count-subarrays-with-fixed-bounds
2529-range-product-queries-of-powers
2626-count-the-number-of-good-subarrays
2689-rearranging-fruits
2699-count-the-number-of-fair-pairs
2720-minimize-the-maximum-difference-of-pairs
2856-count-complete-subarrays-in-an-array
2915-count-of-interesting-subarrays
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3152-maximum-value-of-an-ordered-triplet-ii
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3194-find-words-containing-character
3213-count-subarrays-where-max-element-appears-at-least-k-times
3241-divide-array-into-arrays-with-max-difference
3321-type-of-triangle
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3639-zero-array-transformation-i
3647-zero-array-transformation-iii
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3685-count-subarrays-of-length-three-with-a-condition
3743-reschedule-meetings-for-maximum-free-time-i
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3788-maximum-unique-subarray-sum-after-deletion
3789-maximize-subarrays-after-removing-one-conflicting-pair
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Hash Table

0001-two-sum
0012-integer-to-roman
0013-roman-to-integer
0041-first-missing-positive
0049-group-anagrams
0073-set-matrix-zeroes
0128-longest-consecutive-sequence
0149-max-points-on-a-line
0169-majority-element
0205-isomorphic-strings
0217-contains-duplicate
0242-valid-anagram
0290-word-pattern
0347-top-k-frequent-elements
0496-next-greater-element-i
0594-longest-harmonious-subsequence
0797-rabbits-in-forest
0900-reordered-power-of-2
1218-lowest-common-ancestor-of-deepest-leaves
1500-count-largest-group
1510-find-lucky-integer-in-an-array
1813-maximum-erasure-value
2215-finding-3-digit-even-numbers
2237-longest-palindrome-by-concatenating-two-letter-words
2479-meeting-rooms-iii
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2626-count-the-number-of-good-subarrays
2689-rearranging-fruits
2856-count-complete-subarrays-in-an-array
2915-count-of-interesting-subarrays
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3788-maximum-unique-subarray-sum-after-deletion

String

0012-integer-to-roman
0013-roman-to-integer
0038-count-and-say
0043-multiply-strings
0049-group-anagrams
0067-add-binary
0151-reverse-words-in-a-string
0205-isomorphic-strings
0224-basic-calculator
0227-basic-calculator-ii
0242-valid-anagram
0290-word-pattern
0443-string-compression
0812-rotate-string
0868-push-dominoes
1058-lexicographically-smallest-equivalent-string
1302-delete-characters-to-make-fancy-string
1818-maximum-score-from-removing-substrings
2140-longest-subsequence-repeated-k-times
2237-longest-palindrome-by-concatenating-two-letter-words
2260-divide-a-string-into-groups-of-size-k
2395-longest-binary-subsequence-less-than-or-equal-to-k
2520-using-a-robot-to-print-the-lexicographically-smallest-string
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3194-find-words-containing-character
3360-minimum-deletions-to-make-string-k-special
3396-valid-word
3445-lexicographically-minimum-string-after-removing-stars
3617-find-the-original-typed-string-i
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations
3683-find-the-lexicographically-largest-string-from-the-box-i
3761-maximum-difference-between-even-and-odd-frequency-ii

Sorting

0049-group-anagrams
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0217-contains-duplicate
0242-valid-anagram
0347-top-k-frequent-elements
0368-largest-divisible-subset
0594-longest-harmonious-subsequence
0900-reordered-power-of-2
1095-two-city-scheduling
1478-maximum-number-of-events-that-can-be-attended
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1851-maximum-number-of-events-that-can-be-attended-ii
2123-the-number-of-weak-characters-in-the-game
2180-maximum-number-of-tasks-you-can-assign
2215-finding-3-digit-even-numbers
2387-partition-array-such-that-maximum-difference-is-k
2479-meeting-rooms-iii
2497-maximum-matching-of-players-with-trainers
2689-rearranging-fruits
2699-count-the-number-of-fair-pairs
3241-divide-array-into-arrays-with-max-difference
3321-type-of-triangle
3360-minimum-deletions-to-make-string-k-special
3647-zero-array-transformation-iii

Tree

1218-lowest-common-ancestor-of-deepest-leaves
2400-minimum-score-after-removals-on-a-tree
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Depth-First Search

1218-lowest-common-ancestor-of-deepest-leaves
2400-minimum-score-after-removals-on-a-tree
2438-find-closest-node-to-given-two-nodes
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Breadth-First Search

1218-lowest-common-ancestor-of-deepest-leaves
1424-maximum-candies-you-can-get-from-boxes
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Binary Tree

1218-lowest-common-ancestor-of-deepest-leaves

Math

0007-reverse-integer
0012-integer-to-roman
0013-roman-to-integer
0043-multiply-strings
0050-powx-n
0066-plus-one
0067-add-binary
0149-max-points-on-a-line
0204-count-primes
0224-basic-calculator
0227-basic-calculator-ii
0326-power-of-three
0368-largest-divisible-subset
0797-rabbits-in-forest
0826-soup-servings
0900-reordered-power-of-2
1013-fibonacci-number
1411-convert-binary-number-in-a-linked-list-to-integer
1421-find-numbers-with-even-number-of-digits
1500-count-largest-group
1529-max-difference-you-can-get-from-changing-an-integer
1993-sum-of-all-subset-xor-totals
2050-count-good-numbers
2202-sum-of-k-mirror-numbers
2704-maximum-difference-by-remapping-a-digit
2998-count-symmetric-integers
3172-divisible-and-non-divisible-sums-difference
3201-distribute-candies-among-children-ii
3321-type-of-triangle
3600-find-the-k-th-character-in-string-game-i
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements

Backtracking

1993-sum-of-all-subset-xor-totals
2140-longest-subsequence-repeated-k-times
2170-count-number-of-maximum-bitwise-or-subsets

Bit Manipulation

0067-add-binary
0934-bitwise-ors-of-subarrays
1993-sum-of-all-subset-xor-totals
2170-count-number-of-maximum-bitwise-or-subsets
2400-minimum-score-after-removals-on-a-tree
2498-smallest-subarrays-with-maximum-bitwise-or
2503-longest-subarray-with-maximum-bitwise-and
2529-range-product-queries-of-powers
3600-find-the-k-th-character-in-string-game-i

Combinatorics

1993-sum-of-all-subset-xor-totals
3201-distribute-candies-among-children-ii
3637-count-number-of-balanced-permutations
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements

Enumeration

0204-count-primes
0900-reordered-power-of-2
1656-count-good-triplets
1993-sum-of-all-subset-xor-totals
2140-longest-subsequence-repeated-k-times
2170-count-number-of-maximum-bitwise-or-subsets
2202-sum-of-k-mirror-numbers
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
3761-maximum-difference-between-even-and-odd-frequency-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair

Two Pointers

0026-remove-duplicates-from-sorted-array
0027-remove-element
0075-sort-colors
0088-merge-sorted-array
0151-reverse-words-in-a-string
0443-string-compression
0868-push-dominoes
0908-middle-of-the-linked-list
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2271-rearrange-array-elements-by-sign
2320-find-all-k-distant-indices-in-an-array
2497-maximum-matching-of-players-with-trainers
2699-count-the-number-of-fair-pairs
3683-find-the-lexicographically-largest-string-from-the-box-i

Dynamic Programming

0053-maximum-subarray
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0152-maximum-product-subarray
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0806-domino-and-tromino-tiling
0826-soup-servings
0868-push-dominoes
0934-bitwise-ors-of-subarrays
1013-fibonacci-number
1851-maximum-number-of-events-that-can-be-attended-ii
2061-painting-a-grid-with-three-different-colors
2267-minimum-difference-in-sums-after-removal-of-elements
2395-longest-binary-subsequence-less-than-or-equal-to-k
2882-ways-to-express-an-integer-as-sum-of-powers
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations

Recursion

0050-powx-n
0203-remove-linked-list-elements
0206-reverse-linked-list
0224-basic-calculator
0326-power-of-three
1013-fibonacci-number
2050-count-good-numbers
3600-find-the-k-th-character-in-string-game-i

Binary Search

1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1851-maximum-number-of-events-that-can-be-attended-ii
2180-maximum-number-of-tasks-you-can-assign
2229-maximum-fruits-harvested-after-at-most-k-steps
2280-count-good-triplets-in-an-array
2394-count-subarrays-with-score-less-than-k
2498-smallest-subarrays-with-maximum-bitwise-or
2699-count-the-number-of-fair-pairs
2720-minimize-the-maximum-difference-of-pairs
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Divide and Conquer

0053-maximum-subarray
0169-majority-element
0347-top-k-frequent-elements
2280-count-good-triplets-in-an-array

Binary Indexed Tree

2280-count-good-triplets-in-an-array

Segment Tree

2280-count-good-triplets-in-an-array
3789-maximize-subarrays-after-removing-one-conflicting-pair
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Merge Sort

2280-count-good-triplets-in-an-array

Ordered Set

2280-count-good-triplets-in-an-array
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Sliding Window

0594-longest-harmonious-subsequence
1813-maximum-erasure-value
2229-maximum-fruits-harvested-after-at-most-k-steps
2394-count-subarrays-with-score-less-than-k
2498-smallest-subarrays-with-maximum-bitwise-or
2527-count-subarrays-with-fixed-bounds
2626-count-the-number-of-good-subarrays
2856-count-complete-subarrays-in-an-array
3213-count-subarrays-where-max-element-appears-at-least-k-times
3743-reschedule-meetings-for-maximum-free-time-i
3761-maximum-difference-between-even-and-odd-frequency-ii

Greedy

0797-rabbits-in-forest
1049-minimum-domino-rotations-for-equal-row
1095-two-city-scheduling
1478-maximum-number-of-events-that-can-be-attended
1529-max-difference-you-can-get-from-changing-an-integer
1818-maximum-score-from-removing-substrings
2123-the-number-of-weak-characters-in-the-game
2140-longest-subsequence-repeated-k-times
2180-maximum-number-of-tasks-you-can-assign
2237-longest-palindrome-by-concatenating-two-letter-words
2387-partition-array-such-that-maximum-difference-is-k
2395-longest-binary-subsequence-less-than-or-equal-to-k
2497-maximum-matching-of-players-with-trainers
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2689-rearranging-fruits
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
3241-divide-array-into-arrays-with-max-difference
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3647-zero-array-transformation-iii
3743-reschedule-meetings-for-maximum-free-time-i
3788-maximum-unique-subarray-sum-after-deletion

Stack

0224-basic-calculator
0227-basic-calculator-ii
0496-next-greater-element-i
0682-baseball-game
1818-maximum-score-from-removing-substrings
2123-the-number-of-weak-characters-in-the-game
2520-using-a-robot-to-print-the-lexicographically-smallest-string
3445-lexicographically-minimum-string-after-removing-stars

Monotonic Stack

0496-next-greater-element-i
2123-the-number-of-weak-characters-in-the-game

Simulation

0043-multiply-strings
0054-spiral-matrix
0067-add-binary
0682-baseball-game
2048-build-array-from-permutation
2260-divide-a-string-into-groups-of-size-k
2271-rearrange-array-elements-by-sign
2479-meeting-rooms-iii
3600-find-the-k-th-character-in-string-game-i
3790-fruits-into-baskets-ii

Counting

0169-majority-element
0347-top-k-frequent-elements
0594-longest-harmonious-subsequence
0900-reordered-power-of-2
1510-find-lucky-integer-in-an-array
2140-longest-subsequence-repeated-k-times
2237-longest-palindrome-by-concatenating-two-letter-words
3360-minimum-deletions-to-make-string-k-special
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii

Prefix Sum

2229-maximum-fruits-harvested-after-at-most-k-steps
2394-count-subarrays-with-score-less-than-k
2529-range-product-queries-of-powers
2915-count-of-interesting-subarrays
3639-zero-array-transformation-i
3647-zero-array-transformation-iii
3761-maximum-difference-between-even-and-odd-frequency-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair

Queue

2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds

Monotonic Queue

2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds

Linked List

0203-remove-linked-list-elements
0206-reverse-linked-list
0237-delete-node-in-a-linked-list
0908-middle-of-the-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer

Graph

1424-maximum-candies-you-can-get-from-boxes
2438-find-closest-node-to-given-two-nodes
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Heap (Priority Queue)

0347-top-k-frequent-elements
1478-maximum-number-of-events-that-can-be-attended
2267-minimum-difference-in-sums-after-removal-of-elements
2479-meeting-rooms-iii
3445-lexicographically-minimum-string-after-removing-stars
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3647-zero-array-transformation-iii

Matrix

0054-spiral-matrix
0073-set-matrix-zeroes
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Shortest Path

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

Union Find

0128-longest-consecutive-sequence
1058-lexicographically-smallest-equivalent-string

Trie

0440-k-th-smallest-in-lexicographical-order

Memoization

1013-fibonacci-number
2395-longest-binary-subsequence-less-than-or-equal-to-k

Geometry

0149-max-points-on-a-line

Number Theory

0204-count-primes

Bucket Sort

0347-top-k-frequent-elements

Quickselect

0347-top-k-frequent-elements

Brainteaser

2503-longest-subarray-with-maximum-bitwise-and

Probability and Statistics

0826-soup-servings

String Matching

0812-rotate-string