Leetcode

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

Array

0075-sort-colors
0084-largest-rectangle-in-histogram
0330-patching-array
0502-ipo
0648-replace-words
0853-most-profit-assigning-work
0982-minimum-increment-to-make-array-unique
1037-minimum-number-of-k-consecutive-bit-flips
1370-count-number-of-nice-subarrays
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1605-minimum-number-of-days-to-make-m-bouquets
1675-magnetic-force-between-two-balls
2148-minimum-number-of-moves-to-seat-everyone
3443-maximum-total-reward-using-operations-ii

Greedy

0330-patching-array
0502-ipo
0853-most-profit-assigning-work
0982-minimum-increment-to-make-array-unique
1285-balance-a-binary-search-tree
2148-minimum-number-of-moves-to-seat-everyone

Sorting

0075-sort-colors
0502-ipo
0853-most-profit-assigning-work
0982-minimum-increment-to-make-array-unique
1675-magnetic-force-between-two-balls
2148-minimum-number-of-moves-to-seat-everyone

Dynamic Programming

3443-maximum-total-reward-using-operations-ii

Bit Manipulation

1037-minimum-number-of-k-consecutive-bit-flips
3443-maximum-total-reward-using-operations-ii

Two Pointers

0075-sort-colors
0633-sum-of-square-numbers
0853-most-profit-assigning-work

Stack

0084-largest-rectangle-in-histogram

Monotonic Stack

0084-largest-rectangle-in-histogram

Counting

0982-minimum-increment-to-make-array-unique

Hash Table

0648-replace-words
1370-count-number-of-nice-subarrays

String

0648-replace-words

Trie

0648-replace-words

Heap (Priority Queue)

0502-ipo
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Math

0633-sum-of-square-numbers
1370-count-number-of-nice-subarrays

Binary Search

0633-sum-of-square-numbers
0853-most-profit-assigning-work
1605-minimum-number-of-days-to-make-m-bouquets
1675-magnetic-force-between-two-balls

Sliding Window

1037-minimum-number-of-k-consecutive-bit-flips
1370-count-number-of-nice-subarrays
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Queue

1037-minimum-number-of-k-consecutive-bit-flips
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

Prefix Sum

1037-minimum-number-of-k-consecutive-bit-flips

Divide and Conquer

1285-balance-a-binary-search-tree

Tree

1285-balance-a-binary-search-tree

Depth-First Search

1285-balance-a-binary-search-tree

Binary Search Tree

1285-balance-a-binary-search-tree

Binary Tree

1285-balance-a-binary-search-tree

Graph

1916-find-center-of-star-graph

LeetCode Topics

Greedy

0122-best-time-to-buy-and-sell-stock-ii
0402-remove-k-digits
0455-assign-cookies
0670-maximum-swap
0780-max-chunks-to-make-sorted
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1917-maximum-average-pass-ratio
2089-maximum-matrix-sum
2300-construct-string-with-repeat-limit
2379-maximum-total-importance-of-roads
2395-longest-binary-subsequence-less-than-or-equal-to-k
2616-maximal-score-after-applying-k-operations
2640-maximum-number-of-integers-to-choose-from-a-range-i
3195-separate-black-and-white-balls

Graph

0547-number-of-provinces
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1701-remove-max-number-of-edges-to-keep-graph-fully-traversable
2379-maximum-total-importance-of-roads
2711-minimum-time-to-visit-a-cell-in-a-grid
3189-find-champion-ii
3517-shortest-distance-after-road-addition-queries-i

Sorting

0016-3sum-closest
0049-group-anagrams
0075-sort-colors
0148-sort-list
0215-kth-largest-element-in-an-array
0350-intersection-of-two-arrays-ii
0455-assign-cookies
0539-minimum-time-difference
0780-max-chunks-to-make-sorted
1468-check-if-n-and-its-double-exist
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2379-maximum-total-importance-of-roads
2640-maximum-number-of-integers-to-choose-from-a-range-i
2695-find-score-of-an-array-after-marking-all-elements
2699-count-the-number-of-fair-pairs
2891-maximum-beauty-of-an-array-after-applying-operation
3291-find-if-array-can-be-sorted

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0355-design-twitter
0892-shortest-subarray-with-sum-at-least-k
1917-maximum-average-pass-ratio
2164-two-best-non-overlapping-events
2300-construct-string-with-repeat-limit
2379-maximum-total-importance-of-roads
2616-maximal-score-after-applying-k-operations
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
2711-minimum-time-to-visit-a-cell-in-a-grid
2868-continuous-subarrays
3181-find-building-where-alice-and-bob-can-meet
3555-final-array-state-after-k-multiplication-operations-i

Depth-First Search

0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree
0116-populating-next-right-pointers-in-each-node
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0543-diameter-of-binary-tree
0547-number-of-provinces
0733-flood-fill
0988-flip-equivalent-binary-trees
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
2493-reverse-odd-levels-of-binary-tree
3058-maximum-number-of-k-divisible-components

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0116-populating-next-right-pointers-in-each-node
0547-number-of-provinces
0733-flood-fill
0787-sliding-puzzle
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
2493-reverse-odd-levels-of-binary-tree
2711-minimum-time-to-visit-a-cell-in-a-grid
3517-shortest-distance-after-road-addition-queries-i

Topological Sort

1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph

Union Find

0128-longest-consecutive-sequence
0547-number-of-provinces
1701-remove-max-number-of-edges-to-keep-graph-fully-traversable

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0016-3sum-closest
0042-trapping-rain-water
0046-permutations
0048-rotate-image
0049-group-anagrams
0054-spiral-matrix
0064-minimum-path-sum
0075-sort-colors
0078-subsets
0118-pascals-triangle
0119-pascals-triangle-ii
0120-triangle
0122-best-time-to-buy-and-sell-stock-ii
0128-longest-consecutive-sequence
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0189-rotate-array
0209-minimum-size-subarray-sum
0215-kth-largest-element-in-an-array
0350-intersection-of-two-arrays-ii
0416-partition-equal-subset-sum
0455-assign-cookies
0485-max-consecutive-ones
0525-contiguous-array
0539-minimum-time-difference
0560-subarray-sum-equals-k
0733-flood-fill
0780-max-chunks-to-make-sorted
0787-sliding-puzzle
0792-binary-search
0859-design-circular-deque
0892-shortest-subarray-with-sum-at-least-k
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1147-flip-columns-for-maximum-number-of-equal-rows
1293-three-consecutive-odds
1370-count-number-of-nice-subarrays
1435-xor-queries-of-a-subarray
1468-check-if-n-and-its-double-exist
1538-maximum-points-you-can-obtain-from-cards
1570-final-prices-with-a-special-discount-in-a-shop
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1755-defuse-the-bomb
1786-count-the-number-of-consistent-strings
1886-minimum-limit-of-balls-in-a-bag
1917-maximum-average-pass-ratio
1940-maximum-xor-for-each-query
1972-rotating-the-box
2089-maximum-matrix-sum
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2188-minimized-maximum-of-products-distributed-to-any-store
2232-adding-spaces-to-a-string
2320-find-all-k-distant-indices-in-an-array
2343-count-unguarded-cells-in-the-grid
2356-largest-combination-with-bitwise-and-greater-than-zero
2552-maximum-sum-of-distinct-subarrays-with-length-k
2616-maximal-score-after-applying-k-operations
2640-maximum-number-of-integers-to-choose-from-a-range-i
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
2699-count-the-number-of-fair-pairs
2711-minimum-time-to-visit-a-cell-in-a-grid
2868-continuous-subarrays
2891-maximum-beauty-of-an-array-after-applying-operation
3181-find-building-where-alice-and-bob-can-meet
3291-find-if-array-can-be-sorted
3329-find-the-length-of-the-longest-common-prefix
3380-shortest-subarray-with-or-at-least-k-ii
3427-special-array-ii
3501-delete-nodes-from-linked-list-present-in-array
3517-shortest-distance-after-road-addition-queries-i
3522-find-the-power-of-k-size-subarrays-i
3555-final-array-state-after-k-multiplication-operations-i

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0049-group-anagrams
0128-longest-consecutive-sequence
0141-linked-list-cycle
0142-linked-list-cycle-ii
0350-intersection-of-two-arrays-ii
0355-design-twitter
0525-contiguous-array
0560-subarray-sum-equals-k
0920-uncommon-words-from-two-sentences
0966-binary-subarrays-with-sum
1147-flip-columns-for-maximum-number-of-equal-rows
1370-count-number-of-nice-subarrays
1468-check-if-n-and-its-double-exist
1473-find-the-longest-substring-containing-vowels-in-even-counts
1786-count-the-number-of-consistent-strings
2300-construct-string-with-repeat-limit
2356-largest-combination-with-bitwise-and-greater-than-zero
2552-maximum-sum-of-distinct-subarrays-with-length-k
2599-take-k-of-each-character-from-left-and-right
2640-maximum-number-of-integers-to-choose-from-a-range-i
2695-find-score-of-an-array-after-marking-all-elements
3329-find-the-length-of-the-longest-common-prefix
3501-delete-nodes-from-linked-list-present-in-array

Two Pointers

0016-3sum-closest
0019-remove-nth-node-from-end-of-list
0042-trapping-rain-water
0061-rotate-list
0075-sort-colors
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0148-sort-list
0151-reverse-words-in-a-string
0189-rotate-array
0234-palindrome-linked-list
0350-intersection-of-two-arrays-ii
0455-assign-cookies
0633-sum-of-square-numbers
1468-check-if-n-and-its-double-exist
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1972-rotating-the-box
2232-adding-spaces-to-a-string
2320-find-all-k-distant-indices-in-an-array
2414-move-pieces-to-obtain-a-string
2699-count-the-number-of-fair-pairs
3018-make-string-a-subsequence-using-cyclic-increments
3195-separate-black-and-white-balls

Binary Search

0004-median-of-two-sorted-arrays
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0209-minimum-size-subarray-sum
0222-count-complete-tree-nodes
0350-intersection-of-two-arrays-ii
0633-sum-of-square-numbers
0792-binary-search
0892-shortest-subarray-with-sum-at-least-k
1046-max-consecutive-ones-iii
1468-check-if-n-and-its-double-exist
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1886-minimum-limit-of-balls-in-a-bag
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2188-minimized-maximum-of-products-distributed-to-any-store
2640-maximum-number-of-integers-to-choose-from-a-range-i
2699-count-the-number-of-fair-pairs
2891-maximum-beauty-of-an-array-after-applying-operation
3181-find-building-where-alice-and-bob-can-meet
3427-special-array-ii

Matrix

0048-rotate-image
0054-spiral-matrix
0064-minimum-path-sum
0733-flood-fill
0787-sliding-puzzle
1147-flip-columns-for-maximum-number-of-equal-rows
1972-rotating-the-box
2089-maximum-matrix-sum
2343-count-unguarded-cells-in-the-grid
2711-minimum-time-to-visit-a-cell-in-a-grid

Simulation

0043-multiply-strings
0054-spiral-matrix
2076-sum-of-digits-of-string-after-convert
2232-adding-spaces-to-a-string
2343-count-unguarded-cells-in-the-grid
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
3555-final-array-state-after-k-multiplication-operations-i

Linked List

0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0061-rotate-list
0092-reverse-linked-list-ii
0109-convert-sorted-list-to-binary-search-tree
0116-populating-next-right-pointers-in-each-node
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0148-sort-list
0234-palindrome-linked-list
0355-design-twitter
0859-design-circular-deque
1411-convert-binary-number-in-a-linked-list-to-integer
2871-double-a-number-represented-as-a-linked-list
2903-insert-greatest-common-divisors-in-linked-list
3501-delete-nodes-from-linked-list-present-in-array

Recursion

0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0143-reorder-list
0234-palindrome-linked-list
0326-power-of-three
1013-fibonacci-number

Math

0007-reverse-integer
0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0029-divide-two-integers
0043-multiply-strings
0048-rotate-image
0062-unique-paths
0096-unique-binary-search-trees
0189-rotate-array
0326-power-of-three
0539-minimum-time-difference
0633-sum-of-square-numbers
0670-maximum-swap
1013-fibonacci-number
1370-count-number-of-nice-subarrays
1411-convert-binary-number-in-a-linked-list-to-integer
2202-sum-of-k-mirror-numbers
2491-smallest-even-multiple
2871-double-a-number-represented-as-a-linked-list
2903-insert-greatest-common-divisors-in-linked-list
3555-final-array-state-after-k-multiplication-operations-i

Dynamic Programming

0042-trapping-rain-water
0062-unique-paths
0064-minimum-path-sum
0096-unique-binary-search-trees
0118-pascals-triangle
0119-pascals-triangle-ii
0120-triangle
0122-best-time-to-buy-and-sell-stock-ii
0338-counting-bits
0416-partition-equal-subset-sum
1013-fibonacci-number
2164-two-best-non-overlapping-events
2395-longest-binary-subsequence-less-than-or-equal-to-k

Memoization

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

Bit Manipulation

0029-divide-two-integers
0078-subsets
0222-count-complete-tree-nodes
0338-counting-bits
0476-number-complement
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1786-count-the-number-of-consistent-strings
1940-maximum-xor-for-each-query
2323-minimum-bit-flips-to-convert-number
2356-largest-combination-with-bitwise-and-greater-than-zero
3291-find-if-array-can-be-sorted
3380-shortest-subarray-with-or-at-least-k-ii
3394-minimum-array-end

Prefix Sum

0209-minimum-size-subarray-sum
0525-contiguous-array
0560-subarray-sum-equals-k
0892-shortest-subarray-with-sum-at-least-k
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1538-maximum-points-you-can-obtain-from-cards
1940-maximum-xor-for-each-query
3427-special-array-ii

String

0003-longest-substring-without-repeating-characters
0008-string-to-integer-atoi
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0043-multiply-strings
0049-group-anagrams
0058-length-of-last-word
0151-reverse-words-in-a-string
0402-remove-k-digits
0539-minimum-time-difference
0812-rotate-string
0920-uncommon-words-from-two-sentences
1302-delete-characters-to-make-fancy-string
1473-find-the-longest-substring-containing-vowels-in-even-counts
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1786-count-the-number-of-consistent-strings
2076-sum-of-digits-of-string-after-convert
2232-adding-spaces-to-a-string
2300-construct-string-with-repeat-limit
2395-longest-binary-subsequence-less-than-or-equal-to-k
2414-move-pieces-to-obtain-a-string
2580-circular-sentence
2599-take-k-of-each-character-from-left-and-right
3018-make-string-a-subsequence-using-cyclic-increments
3174-minimum-number-of-changes-to-make-binary-string-beautiful
3195-separate-black-and-white-balls
3329-find-the-length-of-the-longest-common-prefix
3451-string-compression-iii

Stack

0042-trapping-rain-water
0143-reorder-list
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0234-palindrome-linked-list
0402-remove-k-digits
0780-max-chunks-to-make-sorted
1570-final-prices-with-a-special-discount-in-a-shop
1679-shortest-subarray-to-be-removed-to-make-array-sorted
2871-double-a-number-represented-as-a-linked-list
3181-find-building-where-alice-and-bob-can-meet

Tree

0096-unique-binary-search-trees
0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0109-convert-sorted-list-to-binary-search-tree
0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree
0116-populating-next-right-pointers-in-each-node
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0222-count-complete-tree-nodes
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0450-delete-node-in-a-bst
0543-diameter-of-binary-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0988-flip-equivalent-binary-trees
2493-reverse-odd-levels-of-binary-tree
3058-maximum-number-of-k-divisible-components

Binary Tree

0096-unique-binary-search-trees
0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0109-convert-sorted-list-to-binary-search-tree
0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree
0116-populating-next-right-pointers-in-each-node
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0222-count-complete-tree-nodes
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0450-delete-node-in-a-bst
0543-diameter-of-binary-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0988-flip-equivalent-binary-trees
2493-reverse-odd-levels-of-binary-tree

Backtracking

0017-letter-combinations-of-a-phone-number
0046-permutations
0078-subsets

Divide and Conquer

0004-median-of-two-sorted-arrays
0109-convert-sorted-list-to-binary-search-tree
0148-sort-list
0215-kth-largest-element-in-an-array

Quickselect

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

Merge Sort

0148-sort-list

Trie

0014-longest-common-prefix
3329-find-the-length-of-the-longest-common-prefix

Sliding Window

0003-longest-substring-without-repeating-characters
0209-minimum-size-subarray-sum
0892-shortest-subarray-with-sum-at-least-k
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1538-maximum-points-you-can-obtain-from-cards
1755-defuse-the-bomb
2552-maximum-sum-of-distinct-subarrays-with-length-k
2599-take-k-of-each-character-from-left-and-right
2868-continuous-subarrays
2891-maximum-beauty-of-an-array-after-applying-operation
3380-shortest-subarray-with-or-at-least-k-ii
3522-find-the-power-of-k-size-subarrays-i

String Matching

0812-rotate-string
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence

Number Theory

2491-smallest-even-multiple
2903-insert-greatest-common-divisors-in-linked-list

Monotonic Stack

0042-trapping-rain-water
0402-remove-k-digits
0780-max-chunks-to-make-sorted
1570-final-prices-with-a-special-discount-in-a-shop
1679-shortest-subarray-to-be-removed-to-make-array-sorted
3181-find-building-where-alice-and-bob-can-meet

Counting

0920-uncommon-words-from-two-sentences
1786-count-the-number-of-consistent-strings
2300-construct-string-with-repeat-limit
2356-largest-combination-with-bitwise-and-greater-than-zero

Design

0355-design-twitter
0859-design-circular-deque

Queue

0859-design-circular-deque
0892-shortest-subarray-with-sum-at-least-k
2868-continuous-subarrays

Binary Search Tree

0096-unique-binary-search-trees
0098-validate-binary-search-tree
0109-convert-sorted-list-to-binary-search-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0450-delete-node-in-a-bst
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree

Monotonic Queue

0892-shortest-subarray-with-sum-at-least-k
2868-continuous-subarrays

Shortest Path

2711-minimum-time-to-visit-a-cell-in-a-grid

Ordered Set

2868-continuous-subarrays

Binary Indexed Tree

3181-find-building-where-alice-and-bob-can-meet

Segment Tree

3181-find-building-where-alice-and-bob-can-meet

Enumeration

2202-sum-of-k-mirror-numbers

Combinatorics

0062-unique-paths