LeetCode_Questions

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

Two Pointers

0633-sum-of-square-numbers
2572-append-characters-to-string-to-make-subsequence

String

0409-longest-palindrome
0648-replace-words
1044-find-common-characters
1520-number-of-steps-to-reduce-a-number-in-binary-representation-to-one
2168-check-if-numbers-are-ascending-in-a-sentence
2243-check-if-all-as-appears-before-all-bs
2572-append-characters-to-string-to-make-subsequence

Greedy

0409-longest-palindrome
0876-hand-of-straights
1422-divide-array-in-sets-of-k-consecutive-numbers
2572-append-characters-to-string-to-make-subsequence

Bit Manipulation

1520-number-of-steps-to-reduce-a-number-in-binary-representation-to-one

Array

0414-third-maximum-number
0560-subarray-sum-equals-k
0648-replace-words
0876-hand-of-straights
1044-find-common-characters
1137-height-checker
1422-divide-array-in-sets-of-k-consecutive-numbers
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1730-special-array-with-x-elements-greater-than-or-equal-x
2270-find-all-lonely-numbers-in-the-array
2679-count-distinct-numbers-on-board

Binary Search

0633-sum-of-square-numbers
1730-special-array-with-x-elements-greater-than-or-equal-x

Sorting

0414-third-maximum-number
0876-hand-of-straights
1137-height-checker
1422-divide-array-in-sets-of-k-consecutive-numbers
1730-special-array-with-x-elements-greater-than-or-equal-x

Hash Table

0409-longest-palindrome
0560-subarray-sum-equals-k
0648-replace-words
0876-hand-of-straights
1044-find-common-characters
1422-divide-array-in-sets-of-k-consecutive-numbers
2270-find-all-lonely-numbers-in-the-array
2679-count-distinct-numbers-on-board

Trie

0648-replace-words

Prefix Sum

0560-subarray-sum-equals-k

Counting Sort

1137-height-checker
2270-find-all-lonely-numbers-in-the-array

Math

0633-sum-of-square-numbers
2679-count-distinct-numbers-on-board

Queue

1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Sliding Window

1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Heap (Priority Queue)

1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Ordered Set

1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Monotonic Queue

1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Simulation

2679-count-distinct-numbers-on-board

Graph

1916-find-center-of-star-graph

LeetCode Topics

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0041-first-missing-positive
0202-happy-number
0205-isomorphic-strings
0350-intersection-of-two-arrays-ii
0448-find-all-numbers-disappeared-in-an-array
0807-custom-sort-string
0920-uncommon-words-from-two-sentences
0952-word-subsets
0961-n-repeated-element-in-size-2n-array
1160-letter-tile-possibilities
1267-remove-zero-sum-consecutive-nodes-from-linked-list
1502-construct-k-palindrome-strings
1556-make-two-arrays-equal-by-reversing-subarrays
1741-sort-array-by-increasing-frequency
1786-count-the-number-of-consistent-strings
1798-max-number-of-k-sum-pairs
2059-unique-length-3-palindromic-subsequences
2163-kth-distinct-string-in-an-array
2204-find-subsequence-of-length-k-with-the-largest-sum
2308-divide-array-into-equal-pairs
2331-intersection-of-multiple-arrays
2388-replace-elements-in-an-array
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2502-sort-the-people
2532-remove-letter-to-equalize-frequency
2566-number-of-unequal-triplets-in-array
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
2677-cousins-in-binary-tree-ii
2685-first-completely-painted-row-or-column
2766-find-the-prefix-common-array-of-two-arrays
2856-count-complete-subarrays-in-an-array
3227-find-missing-and-repeated-values
3421-count-pairs-that-form-a-complete-day-i
3455-minimum-length-of-string-after-operations
3501-delete-nodes-from-linked-list-present-in-array
3507-minimum-pair-removal-to-sort-array-i
3519-find-the-number-of-winning-players
3581-the-two-sneaky-numbers-of-digitville
3656-minimum-number-of-operations-to-make-elements-in-array-distinct

String

0003-longest-substring-without-repeating-characters
0125-valid-palindrome
0151-reverse-words-in-a-string
0205-isomorphic-strings
0392-is-subsequence
0807-custom-sort-string
0812-rotate-string
0920-uncommon-words-from-two-sentences
0952-word-subsets
1160-letter-tile-possibilities
1298-reverse-substrings-between-each-pair-of-parentheses
1502-construct-k-palindrome-strings
1537-maximum-score-after-splitting-a-string
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1786-count-the-number-of-consistent-strings
1894-merge-strings-alternately
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
2021-remove-all-occurrences-of-a-substring
2059-unique-length-3-palindromic-subsequences
2093-check-if-string-is-a-prefix-of-array
2095-minimum-number-of-swaps-to-make-the-string-balanced
2163-kth-distinct-string-in-an-array
2221-check-if-a-parentheses-string-can-be-valid
2232-adding-spaces-to-a-string
2292-counting-words-with-a-given-prefix
2341-count-prefixes-of-a-given-string
2381-shifting-letters-ii
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2465-shifting-letters-ii
2502-sort-the-people
2532-remove-letter-to-equalize-frequency
2691-count-vowel-strings-in-ranges
2727-number-of-senior-citizens
2800-minimum-string-length-after-removing-substrings
3018-make-string-a-subsequence-using-cyclic-increments
3055-maximum-odd-binary-number
3309-count-prefix-and-suffix-pairs-i
3396-valid-word
3447-clear-digits
3455-minimum-length-of-string-after-operations

Sorting

0215-kth-largest-element-in-an-array
0350-intersection-of-two-arrays-ii
0807-custom-sort-string
0948-sort-an-array
1556-make-two-arrays-equal-by-reversing-subarrays
1615-range-sum-of-sorted-subarray-sums
1730-special-array-with-x-elements-greater-than-or-equal-x
1741-sort-array-by-increasing-frequency
1798-max-number-of-k-sum-pairs
2180-maximum-number-of-tasks-you-can-assign
2204-find-subsequence-of-length-k-with-the-largest-sum
2331-intersection-of-multiple-arrays
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2497-maximum-matching-of-players-with-trainers
2502-sort-the-people
2566-number-of-unequal-triplets-in-array
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
3219-make-lexicographically-smallest-array-by-swapping-elements
3241-divide-array-into-arrays-with-max-difference
3778-transform-array-by-parity

Two Pointers

0031-next-permutation
0125-valid-palindrome
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0202-happy-number
0350-intersection-of-two-arrays-ii
0392-is-subsequence
0528-swapping-nodes-in-a-linked-list
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1615-range-sum-of-sorted-subarray-sums
1798-max-number-of-k-sum-pairs
1894-merge-strings-alternately
2093-check-if-string-is-a-prefix-of-array
2095-minimum-number-of-swaps-to-make-the-string-balanced
2180-maximum-number-of-tasks-you-can-assign
2232-adding-spaces-to-a-string
2481-strictly-palindromic-number
2497-maximum-matching-of-players-with-trainers
2581-divide-players-into-teams-of-equal-skill
3018-make-string-a-subsequence-using-cyclic-increments

Array

0001-two-sum
0031-next-permutation
0041-first-missing-positive
0167-two-sum-ii-input-array-is-sorted
0215-kth-largest-element-in-an-array
0350-intersection-of-two-arrays-ii
0407-trapping-rain-water-ii
0448-find-all-numbers-disappeared-in-an-array
0498-diagonal-traverse
0724-find-pivot-index
0854-making-a-large-island
0948-sort-an-array
0952-word-subsets
0961-n-repeated-element-in-size-2n-array
1390-four-divisors
1402-count-square-submatrices-with-all-ones
1421-find-numbers-with-even-number-of-digits
1496-lucky-numbers-in-a-matrix
1556-make-two-arrays-equal-by-reversing-subarrays
1570-final-prices-with-a-special-discount-in-a-shop
1603-running-sum-of-1d-array
1615-range-sum-of-sorted-subarray-sums
1656-count-good-triplets
1690-maximum-length-of-subarray-with-positive-product
1730-special-array-with-x-elements-greater-than-or-equal-x
1741-sort-array-by-increasing-frequency
1786-count-the-number-of-consistent-strings
1798-max-number-of-k-sum-pairs
1833-find-the-highest-altitude
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1927-maximum-ascending-subarray-sum
1940-maximum-xor-for-each-query
1993-sum-of-all-subset-xor-totals
2093-check-if-string-is-a-prefix-of-array
2094-remove-stones-to-minimize-the-total
2102-find-the-middle-index-in-array
2132-convert-1d-array-into-2d-array
2145-grid-game
2163-kth-distinct-string-in-an-array
2180-maximum-number-of-tasks-you-can-assign
2204-find-subsequence-of-length-k-with-the-largest-sum
2232-adding-spaces-to-a-string
2255-minimum-swaps-to-group-all-1s-together-ii
2292-counting-words-with-a-given-prefix
2308-divide-array-into-equal-pairs
2331-intersection-of-multiple-arrays
2341-count-prefixes-of-a-given-string
2342-minimum-average-difference
2358-number-of-ways-to-split-array
2381-shifting-letters-ii
2388-replace-elements-in-an-array
2454-largest-local-values-in-a-matrix
2465-shifting-letters-ii
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2497-maximum-matching-of-players-with-trainers
2502-sort-the-people
2533-bitwise-xor-of-all-pairings
2542-average-value-of-even-numbers-that-are-divisible-by-three
2566-number-of-unequal-triplets-in-array
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2616-maximal-score-after-applying-k-operations
2640-maximum-number-of-integers-to-choose-from-a-range-i
2685-first-completely-painted-row-or-column
2691-count-vowel-strings-in-ranges
2714-left-and-right-sum-differences
2727-number-of-senior-citizens
2764-maximum-number-of-fish-in-a-grid
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
2856-count-complete-subarrays-in-an-array
3219-make-lexicographically-smallest-array-by-swapping-elements
3221-find-the-peaks
3227-find-missing-and-repeated-values
3241-divide-array-into-arrays-with-max-difference
3309-count-prefix-and-suffix-pairs-i
3332-minimum-operations-to-exceed-threshold-value-ii
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3415-check-if-grid-satisfies-conditions
3421-count-pairs-that-form-a-complete-day-i
3422-find-the-n-th-value-after-k-seconds
3427-special-array-ii
3501-delete-nodes-from-linked-list-present-in-array
3507-minimum-pair-removal-to-sort-array-i
3515-find-if-digit-game-can-be-won
3519-find-the-number-of-winning-players
3522-find-the-power-of-k-size-subarrays-i
3555-final-array-state-after-k-multiplication-operations-i
3581-the-two-sneaky-numbers-of-digitville
3606-minimum-element-after-replacement-with-digit-sum
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3685-count-subarrays-of-length-three-with-a-condition
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3778-transform-array-by-parity

Binary Search

0167-two-sum-ii-input-array-is-sorted
0350-intersection-of-two-arrays-ii
1615-range-sum-of-sorted-subarray-sums
1730-special-array-with-x-elements-greater-than-or-equal-x
2180-maximum-number-of-tasks-you-can-assign
2586-longest-square-streak-in-an-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
3427-special-array-ii

Counting

0920-uncommon-words-from-two-sentences
1160-letter-tile-possibilities
1502-construct-k-palindrome-strings
1786-count-the-number-of-consistent-strings
2163-kth-distinct-string-in-an-array
2308-divide-array-into-equal-pairs
2331-intersection-of-multiple-arrays
2532-remove-letter-to-equalize-frequency
3421-count-pairs-that-form-a-complete-day-i
3455-minimum-length-of-string-after-operations
3519-find-the-number-of-winning-players
3778-transform-array-by-parity

Linked List

0002-add-two-numbers
0528-swapping-nodes-in-a-linked-list
1267-remove-zero-sum-consecutive-nodes-from-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer
2182-find-the-minimum-and-maximum-number-of-nodes-between-critical-points
2903-insert-greatest-common-divisors-in-linked-list
3501-delete-nodes-from-linked-list-present-in-array
3507-minimum-pair-removal-to-sort-array-i

Stack

1298-reverse-substrings-between-each-pair-of-parentheses
1570-final-prices-with-a-special-discount-in-a-shop
2021-remove-all-occurrences-of-a-substring
2095-minimum-number-of-swaps-to-make-the-string-balanced
2221-check-if-a-parentheses-string-can-be-valid
2800-minimum-string-length-after-removing-substrings
3447-clear-digits

Matrix

0407-trapping-rain-water-ii
0498-diagonal-traverse
0854-making-a-large-island
1402-count-square-submatrices-with-all-ones
1496-lucky-numbers-in-a-matrix
2132-convert-1d-array-into-2d-array
2145-grid-game
2454-largest-local-values-in-a-matrix
2685-first-completely-painted-row-or-column
2764-maximum-number-of-fish-in-a-grid
3227-find-missing-and-repeated-values
3415-check-if-grid-satisfies-conditions

Bit Manipulation

0231-power-of-two
0338-counting-bits
0371-sum-of-two-integers
0476-number-complement
0693-binary-number-with-alternating-bits
0767-prime-number-of-set-bits-in-binary-representation
1054-complement-of-base-10-integer
1732-minimum-one-bit-operations-to-make-integers-zero
1786-count-the-number-of-consistent-strings
1940-maximum-xor-for-each-query
1993-sum-of-all-subset-xor-totals
2059-unique-length-3-palindromic-subsequences
2308-divide-array-into-equal-pairs
2323-minimum-bit-flips-to-convert-number
2533-bitwise-xor-of-all-pairings
2659-number-of-even-and-odd-bits
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
3394-minimum-array-end

Divide and Conquer

0215-kth-largest-element-in-an-array
0948-sort-an-array

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0407-trapping-rain-water-ii
0948-sort-an-array
2094-remove-stones-to-minimize-the-total
2204-find-subsequence-of-length-k-with-the-largest-sum
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2616-maximal-score-after-applying-k-operations
3332-minimum-operations-to-exceed-threshold-value-ii
3507-minimum-pair-removal-to-sort-array-i
3555-final-array-state-after-k-multiplication-operations-i

Merge Sort

0948-sort-an-array

Bucket Sort

0948-sort-an-array

Radix Sort

0948-sort-an-array

Counting Sort

0948-sort-an-array

Math

0002-add-two-numbers
0009-palindrome-number
0070-climbing-stairs
0202-happy-number
0231-power-of-two
0371-sum-of-two-integers
0767-prime-number-of-set-bits-in-binary-representation
1013-fibonacci-number
1236-n-th-tribonacci-number
1390-four-divisors
1411-convert-binary-number-in-a-linked-list-to-integer
1421-find-numbers-with-even-number-of-digits
1585-the-kth-factor-of-n
1993-sum-of-all-subset-xor-totals
2481-strictly-palindromic-number
2542-average-value-of-even-numbers-that-are-divisible-by-three
2610-closest-prime-numbers-in-range
2903-insert-greatest-common-divisors-in-linked-list
3055-maximum-odd-binary-number
3227-find-missing-and-repeated-values
3371-harshad-number
3422-find-the-n-th-value-after-k-seconds
3515-find-if-digit-game-can-be-won
3555-final-array-state-after-k-multiplication-operations-i
3581-the-two-sneaky-numbers-of-digitville
3606-minimum-element-after-replacement-with-digit-sum
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements

Number Theory

1585-the-kth-factor-of-n
2610-closest-prime-numbers-in-range
2903-insert-greatest-common-divisors-in-linked-list

Sliding Window

0003-longest-substring-without-repeating-characters
1567-maximum-number-of-vowels-in-a-substring-of-given-length
2255-minimum-swaps-to-group-all-1s-together-ii
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2856-count-complete-subarrays-in-an-array
3522-find-the-power-of-k-size-subarrays-i

Brainteaser

2481-strictly-palindromic-number
2533-bitwise-xor-of-all-pairings

Simulation

0498-diagonal-traverse
2021-remove-all-occurrences-of-a-substring
2132-convert-1d-array-into-2d-array
2232-adding-spaces-to-a-string
2388-replace-elements-in-an-array
2800-minimum-string-length-after-removing-substrings
3332-minimum-operations-to-exceed-threshold-value-ii
3422-find-the-n-th-value-after-k-seconds
3447-clear-digits
3507-minimum-pair-removal-to-sort-array-i
3555-final-array-state-after-k-multiplication-operations-i

Greedy

1502-construct-k-palindrome-strings
1690-maximum-length-of-subarray-with-positive-product
2094-remove-stones-to-minimize-the-total
2095-minimum-number-of-swaps-to-make-the-string-balanced
2180-maximum-number-of-tasks-you-can-assign
2221-check-if-a-parentheses-string-can-be-valid
2497-maximum-matching-of-players-with-trainers
2616-maximal-score-after-applying-k-operations
2640-maximum-number-of-integers-to-choose-from-a-range-i
3055-maximum-odd-binary-number
3241-divide-array-into-arrays-with-max-difference

Prefix Sum

0724-find-pivot-index
1537-maximum-score-after-splitting-a-string
1603-running-sum-of-1d-array
1833-find-the-highest-altitude
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1940-maximum-xor-for-each-query
2059-unique-length-3-palindromic-subsequences
2102-find-the-middle-index-in-array
2145-grid-game
2342-minimum-average-difference
2358-number-of-ways-to-split-array
2381-shifting-letters-ii
2465-shifting-letters-ii
2691-count-vowel-strings-in-ranges
2714-left-and-right-sum-differences
3422-find-the-n-th-value-after-k-seconds
3427-special-array-ii

Combinatorics

1993-sum-of-all-subset-xor-totals
3422-find-the-n-th-value-after-k-seconds
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements

Tree

0988-flip-equivalent-binary-trees
2493-reverse-odd-levels-of-binary-tree
2677-cousins-in-binary-tree-ii

Depth-First Search

0684-redundant-connection
0854-making-a-large-island
0988-flip-equivalent-binary-trees
2493-reverse-odd-levels-of-binary-tree
2677-cousins-in-binary-tree-ii
2764-maximum-number-of-fish-in-a-grid

Breadth-First Search

0407-trapping-rain-water-ii
0684-redundant-connection
0854-making-a-large-island
2493-reverse-odd-levels-of-binary-tree
2583-divide-nodes-into-the-maximum-number-of-groups
2677-cousins-in-binary-tree-ii
2764-maximum-number-of-fish-in-a-grid

Binary Tree

0988-flip-equivalent-binary-trees
2493-reverse-odd-levels-of-binary-tree
2677-cousins-in-binary-tree-ii

Dynamic Programming

0070-climbing-stairs
0338-counting-bits
0392-is-subsequence
1013-fibonacci-number
1236-n-th-tribonacci-number
1402-count-square-submatrices-with-all-ones
1690-maximum-length-of-subarray-with-positive-product
1732-minimum-one-bit-operations-to-make-integers-zero
2586-longest-square-streak-in-an-array

Memoization

0070-climbing-stairs
1013-fibonacci-number
1236-n-th-tribonacci-number
1732-minimum-one-bit-operations-to-make-integers-zero

Recursion

0002-add-two-numbers
0231-power-of-two
1013-fibonacci-number

String Matching

0812-rotate-string
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i

Monotonic Stack

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

Enumeration

1656-count-good-triplets
1993-sum-of-all-subset-xor-totals
3221-find-the-peaks

Quickselect

0215-kth-largest-element-in-an-array

Trie

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

Rolling Hash

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

Hash Function

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

Union Find

0684-redundant-connection
0854-making-a-large-island
2583-divide-nodes-into-the-maximum-number-of-groups
2764-maximum-number-of-fish-in-a-grid
3219-make-lexicographically-smallest-array-by-swapping-elements

Graph

0684-redundant-connection
2583-divide-nodes-into-the-maximum-number-of-groups

Database

0584-find-customer-referee
0595-big-countries
1908-recyclable-and-low-fat-products

Backtracking

1160-letter-tile-possibilities
1993-sum-of-all-subset-xor-totals

Queue

2180-maximum-number-of-tasks-you-can-assign

Monotonic Queue

2180-maximum-number-of-tasks-you-can-assign

Doubly-Linked List

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

Ordered Set

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