Data Structures and Algorithms Practice

This repository contains solutions to various data structures and algorithms practice questions from LeetCode and GeeksforGeeks. Each problem is solved in C++, and the solutions are organized for each questions separately.

Contributing

Acknowledgments

Two Pointers

0026-remove-duplicates-from-sorted-array
0027-remove-element
0061-rotate-list
0075-sort-colors
0088-merge-sorted-array
0125-valid-palindrome
0148-sort-list
0344-reverse-string
0633-sum-of-square-numbers
0853-most-profit-assigning-work
2392-successful-pairs-of-spells-and-potions
2497-maximum-matching-of-players-with-trainers
2572-append-characters-to-string-to-make-subsequence

String

0012-integer-to-roman
0014-longest-common-prefix
0020-valid-parentheses
0067-add-binary
0125-valid-palindrome
0171-excel-sheet-column-number
0344-reverse-string
0409-longest-palindrome
0648-replace-words
1044-find-common-characters
2572-append-characters-to-string-to-make-subsequence

Trie

0014-longest-common-prefix
0648-replace-words

Greedy

0330-patching-array
0409-longest-palindrome
0502-ipo
0561-array-partition
0853-most-profit-assigning-work
0876-hand-of-straights
0982-minimum-increment-to-make-array-unique
1285-balance-a-binary-search-tree
1422-divide-array-in-sets-of-k-consecutive-numbers
2148-minimum-number-of-moves-to-seat-everyone
2497-maximum-matching-of-players-with-trainers
2572-append-characters-to-string-to-make-subsequence

Hash Table

0012-integer-to-roman
0409-longest-palindrome
0523-continuous-subarray-sum
0648-replace-words
0876-hand-of-straights
1016-subarray-sums-divisible-by-k
1044-find-common-characters
1217-relative-sort-array
1370-count-number-of-nice-subarrays
1422-divide-array-in-sets-of-k-consecutive-numbers

Array

0026-remove-duplicates-from-sorted-array
0027-remove-element
0035-search-insert-position
0075-sort-colors
0088-merge-sorted-array
0108-convert-sorted-array-to-binary-search-tree
0330-patching-array
0502-ipo
0523-continuous-subarray-sum
0561-array-partition
0648-replace-words
0853-most-profit-assigning-work
0876-hand-of-straights
0948-sort-an-array
0982-minimum-increment-to-make-array-unique
1016-subarray-sums-divisible-by-k
1037-minimum-number-of-k-consecutive-bit-flips
1044-find-common-characters
1137-height-checker
1138-grumpy-bookstore-owner
1217-relative-sort-array
1370-count-number-of-nice-subarrays
1422-divide-array-in-sets-of-k-consecutive-numbers
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
2392-successful-pairs-of-spells-and-potions
2497-maximum-matching-of-players-with-trainers

Binary Search

0035-search-insert-position
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
2392-successful-pairs-of-spells-and-potions

Sorting

0075-sort-colors
0088-merge-sorted-array
0148-sort-list
0502-ipo
0561-array-partition
0853-most-profit-assigning-work
0876-hand-of-straights
0948-sort-an-array
0982-minimum-increment-to-make-array-unique
1137-height-checker
1217-relative-sort-array
1422-divide-array-in-sets-of-k-consecutive-numbers
1675-magnetic-force-between-two-balls
2148-minimum-number-of-moves-to-seat-everyone
2392-successful-pairs-of-spells-and-potions
2497-maximum-matching-of-players-with-trainers

Linked List

0061-rotate-list
0083-remove-duplicates-from-sorted-list
0148-sort-list

Math

0012-integer-to-roman
0067-add-binary
0171-excel-sheet-column-number
0523-continuous-subarray-sum
0633-sum-of-square-numbers
1370-count-number-of-nice-subarrays

Prefix Sum

0523-continuous-subarray-sum
1016-subarray-sums-divisible-by-k
1037-minimum-number-of-k-consecutive-bit-flips

Counting Sort

0561-array-partition
0948-sort-an-array
0982-minimum-increment-to-make-array-unique
1137-height-checker
1217-relative-sort-array

Divide and Conquer

0108-convert-sorted-array-to-binary-search-tree
0148-sort-list
0948-sort-an-array
1285-balance-a-binary-search-tree

Heap (Priority Queue)

0502-ipo
0948-sort-an-array
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Merge Sort

0148-sort-list
0948-sort-an-array

Bucket Sort

0948-sort-an-array

Radix Sort

0948-sort-an-array

Stack

0020-valid-parentheses
0094-binary-tree-inorder-traversal

Bit Manipulation

0067-add-binary
1037-minimum-number-of-k-consecutive-bit-flips

Simulation

0067-add-binary

Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0104-maximum-depth-of-binary-tree
0108-convert-sorted-array-to-binary-search-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0538-convert-bst-to-greater-tree
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Depth-First Search

0094-binary-tree-inorder-traversal
0100-same-tree
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0538-convert-bst-to-greater-tree
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Breadth-First Search

0100-same-tree
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum

Binary Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0104-maximum-depth-of-binary-tree
0108-convert-sorted-array-to-binary-search-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0538-convert-bst-to-greater-tree
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Sliding Window

1037-minimum-number-of-k-consecutive-bit-flips
1138-grumpy-bookstore-owner
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

Binary Search Tree

0108-convert-sorted-array-to-binary-search-tree
0538-convert-bst-to-greater-tree
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Graph

1916-find-center-of-star-graph

LeetCode Topics

Depth-First Search

0145-binary-tree-postorder-traversal
0386-lexicographical-numbers
0501-find-mode-in-binary-search-tree
0515-find-largest-value-in-each-tree-row
0776-n-ary-tree-postorder-traversal
0988-flip-equivalent-binary-trees
0999-regions-cut-by-slashes
1207-delete-nodes-and-return-forest
1350-remove-sub-folders-from-the-filesystem
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1484-linked-list-in-binary-tree
1691-minimum-number-of-days-to-disconnect-island
2035-count-sub-islands
2201-valid-arrangement-of-pairs
2217-step-by-step-directions-from-a-binary-tree-node-to-another
2493-reverse-odd-levels-of-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2677-cousins-in-binary-tree-ii
3058-maximum-number-of-k-divisible-components
3439-find-minimum-diameter-after-merging-two-trees

Breadth-First Search

0515-find-largest-value-in-each-tree-row
0787-sliding-puzzle
0999-regions-cut-by-slashes
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1484-linked-list-in-binary-tree
1691-minimum-number-of-days-to-disconnect-island
2035-count-sub-islands
2171-second-minimum-time-to-reach-destination
2375-minimum-obstacle-removal-to-reach-corner
2493-reverse-odd-levels-of-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2646-kth-largest-sum-in-a-binary-tree
2677-cousins-in-binary-tree-ii
2711-minimum-time-to-visit-a-cell-in-a-grid
3439-find-minimum-diameter-after-merging-two-trees
3517-shortest-distance-after-road-addition-queries-i

Graph

1325-path-with-maximum-probability
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
2171-second-minimum-time-to-reach-destination
2201-valid-arrangement-of-pairs
2375-minimum-obstacle-removal-to-reach-corner
2472-build-a-matrix-with-conditions
2711-minimum-time-to-visit-a-cell-in-a-grid
2803-modify-graph-edge-weights
3189-find-champion-ii
3439-find-minimum-diameter-after-merging-two-trees
3517-shortest-distance-after-road-addition-queries-i

Topological Sort

1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
2472-build-a-matrix-with-conditions

Tree

0145-binary-tree-postorder-traversal
0501-find-mode-in-binary-search-tree
0515-find-largest-value-in-each-tree-row
0776-n-ary-tree-postorder-traversal
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0988-flip-equivalent-binary-trees
1207-delete-nodes-and-return-forest
1484-linked-list-in-binary-tree
2217-step-by-step-directions-from-a-binary-tree-node-to-another
2306-create-binary-tree-from-descriptions
2493-reverse-odd-levels-of-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2646-kth-largest-sum-in-a-binary-tree
2677-cousins-in-binary-tree-ii
3058-maximum-number-of-k-divisible-components
3439-find-minimum-diameter-after-merging-two-trees

Binary Search Tree

0278-first-bad-version
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0501-find-mode-in-binary-search-tree
0719-find-k-th-smallest-pair-distance
0729-my-calendar-i
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0792-binary-search
1468-check-if-n-and-its-double-exist
1615-range-sum-of-sorted-subarray-sums
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1766-minimum-number-of-removals-to-make-mountain-array
1886-minimum-limit-of-balls-in-a-bag
2006-find-the-student-that-will-replace-the-chalk
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2188-minimized-maximum-of-products-distributed-to-any-store
2586-longest-square-streak-in-an-array
2634-minimum-common-value
2640-maximum-number-of-integers-to-choose-from-a-range-i
2699-count-the-number-of-fair-pairs
2716-prime-subtraction-operation
2720-minimize-the-maximum-difference-of-pairs
2891-maximum-beauty-of-an-array-after-applying-operation
3181-find-building-where-alice-and-bob-can-meet
3267-find-longest-special-substring-that-occurs-thrice-i
3427-special-array-ii

Binary Tree

0145-binary-tree-postorder-traversal
0501-find-mode-in-binary-search-tree
0515-find-largest-value-in-each-tree-row
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0988-flip-equivalent-binary-trees
1207-delete-nodes-and-return-forest
1484-linked-list-in-binary-tree
2217-step-by-step-directions-from-a-binary-tree-node-to-another
2306-create-binary-tree-from-descriptions
2493-reverse-odd-levels-of-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2646-kth-largest-sum-in-a-binary-tree
2677-cousins-in-binary-tree-ii

Array

0001-two-sum
0040-combination-sum-ii
0054-spiral-matrix
0084-largest-rectangle-in-histogram
0179-largest-number
0219-contains-duplicate-ii
0283-move-zeroes
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0494-target-sum
0632-smallest-range-covering-elements-from-k-lists
0682-baseball-game
0719-find-k-th-smallest-pair-distance
0729-my-calendar-i
0780-max-chunks-to-make-sorted
0787-sliding-puzzle
0792-binary-search
0859-design-circular-deque
0870-magic-squares-in-grid
0906-walking-robot-simulation
0948-sort-an-array
0999-regions-cut-by-slashes
1002-maximum-width-ramp
1025-minimum-cost-for-tickets
1063-best-sightseeing-pair
1147-flip-columns-for-maximum-number-of-equal-rows
1196-filling-bookcase-shelves
1207-delete-nodes-and-return-forest
1240-stone-game-ii
1256-rank-transform-of-an-array
1293-three-consecutive-odds
1325-path-with-maximum-probability
1333-sort-the-jumbled-numbers
1350-remove-sub-folders-from-the-filesystem
1392-find-the-difference-of-two-arrays
1402-count-square-submatrices-with-all-ones
1435-xor-queries-of-a-subarray
1468-check-if-n-and-its-double-exist
1496-lucky-numbers-in-a-matrix
1497-design-a-stack-with-increment-operation
1511-count-number-of-teams
1556-make-two-arrays-equal-by-reversing-subarrays
1570-final-prices-with-a-special-discount-in-a-shop
1615-range-sum-of-sorted-subarray-sums
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1620-check-if-array-pairs-are-divisible-by-k
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1691-minimum-number-of-days-to-disconnect-island
1694-make-sum-divisible-by-p
1711-find-valid-matrix-given-row-and-column-sums
1720-crawler-log-folder
1741-sort-array-by-increasing-frequency
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1755-defuse-the-bomb
1766-minimum-number-of-removals-to-make-mountain-array
1786-count-the-number-of-consistent-strings
1803-average-waiting-time
1886-minimum-limit-of-balls-in-a-bag
1917-maximum-average-pass-ratio
1923-sentence-similarity-iii
1951-find-the-winner-of-the-circular-game
1972-rotating-the-box
2006-find-the-student-that-will-replace-the-chalk
2035-count-sub-islands
2054-the-number-of-the-smallest-unoccupied-chair
2067-maximum-number-of-points-with-cost
2089-maximum-matrix-sum
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2163-kth-distinct-string-in-an-array
2164-two-best-non-overlapping-events
2170-count-number-of-maximum-bitwise-or-subsets
2179-most-beautiful-item-for-each-query
2188-minimized-maximum-of-products-distributed-to-any-store
2232-adding-spaces-to-a-string
2255-minimum-swaps-to-group-all-1s-together-ii
2306-create-binary-tree-from-descriptions
2331-intersection-of-multiple-arrays
2343-count-unguarded-cells-in-the-grid
2375-minimum-obstacle-removal-to-reach-corner
2411-spiral-matrix-iv
2472-build-a-matrix-with-conditions
2488-divide-intervals-into-minimum-number-of-groups
2494-sum-of-prefix-scores-of-strings
2502-sort-the-people
2503-longest-subarray-with-maximum-bitwise-and
2545-height-of-binary-tree-after-subtree-removal-queries
2554-minimum-total-distance-traveled
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2616-maximal-score-after-applying-k-operations
2634-minimum-common-value
2640-maximum-number-of-integers-to-choose-from-a-range-i
2692-take-gifts-from-the-richest-pile
2699-count-the-number-of-fair-pairs
2711-minimum-time-to-visit-a-cell-in-a-grid
2716-prime-subtraction-operation
2720-minimize-the-maximum-difference-of-pairs
2727-number-of-senior-citizens
2755-extra-characters-in-a-string
2794-maximum-number-of-moves-in-a-grid
2846-robot-collisions
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
0142-linked-list-cycle-ii
0202-happy-number
0219-contains-duplicate-ii
0264-ugly-number-ii
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0432-all-oone-data-structure
0567-permutation-in-string
0632-smallest-range-covering-elements-from-k-lists
0726-number-of-atoms
0870-magic-squares-in-grid
0906-walking-robot-simulation
0920-uncommon-words-from-two-sentences
0999-regions-cut-by-slashes
1147-flip-columns-for-maximum-number-of-equal-rows
1207-delete-nodes-and-return-forest
1256-rank-transform-of-an-array
1392-find-the-difference-of-two-arrays
1468-check-if-n-and-its-double-exist
1556-make-two-arrays-equal-by-reversing-subarrays
1620-check-if-array-pairs-are-divisible-by-k
1694-make-sum-divisible-by-p
1715-split-a-string-into-the-max-number-of-unique-substrings
1741-sort-array-by-increasing-frequency
1786-count-the-number-of-consistent-strings
2054-the-number-of-the-smallest-unoccupied-chair
2163-kth-distinct-string-in-an-array
2300-construct-string-with-repeat-limit
2306-create-binary-tree-from-descriptions
2331-intersection-of-multiple-arrays
2502-sort-the-people
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2599-take-k-of-each-character-from-left-and-right
2634-minimum-common-value
2640-maximum-number-of-integers-to-choose-from-a-range-i
2677-cousins-in-binary-tree-ii
2755-extra-characters-in-a-string
3267-find-longest-special-substring-that-occurs-thrice-i
3276-minimum-number-of-pushes-to-type-word-ii
3329-find-the-length-of-the-longest-common-prefix
3501-delete-nodes-from-linked-list-present-in-array

Sliding Window

0219-contains-duplicate-ii
0567-permutation-in-string
0632-smallest-range-covering-elements-from-k-lists
1755-defuse-the-bomb
2255-minimum-swaps-to-group-all-1s-together-ii
2599-take-k-of-each-character-from-left-and-right
2868-continuous-subarrays
2891-maximum-beauty-of-an-array-after-applying-operation
3267-find-longest-special-substring-that-occurs-thrice-i
3380-shortest-subarray-with-or-at-least-k-ii
3522-find-the-power-of-k-size-subarrays-i

Two Pointers

0142-linked-list-cycle-ii
0202-happy-number
0283-move-zeroes
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0567-permutation-in-string
0719-find-k-th-smallest-pair-distance
0874-backspace-string-compare
0908-middle-of-the-linked-list
1468-check-if-n-and-its-double-exist
1615-range-sum-of-sorted-subarray-sums
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1923-sentence-similarity-iii
1972-rotating-the-box
2095-minimum-number-of-swaps-to-make-the-string-balanced
2232-adding-spaces-to-a-string
2414-move-pieces-to-obtain-a-string
2488-divide-intervals-into-minimum-number-of-groups
2581-divide-players-into-teams-of-equal-skill
2634-minimum-common-value
2699-count-the-number-of-fair-pairs
3018-make-string-a-subsequence-using-cyclic-increments
3195-separate-black-and-white-balls

Sorting

0179-largest-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0632-smallest-range-covering-elements-from-k-lists
0719-find-k-th-smallest-pair-distance
0726-number-of-atoms
0780-max-chunks-to-make-sorted
0948-sort-an-array
1256-rank-transform-of-an-array
1333-sort-the-jumbled-numbers
1468-check-if-n-and-its-double-exist
1556-make-two-arrays-equal-by-reversing-subarrays
1615-range-sum-of-sorted-subarray-sums
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1741-sort-array-by-increasing-frequency
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2331-intersection-of-multiple-arrays
2488-divide-intervals-into-minimum-number-of-groups
2502-sort-the-people
2554-minimum-total-distance-traveled
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
2646-kth-largest-sum-in-a-binary-tree
2699-count-the-number-of-fair-pairs
2846-robot-collisions
2891-maximum-beauty-of-an-array-after-applying-operation
3276-minimum-number-of-pushes-to-type-word-ii
3291-find-if-array-can-be-sorted

Counting

0920-uncommon-words-from-two-sentences
1620-check-if-array-pairs-are-divisible-by-k
1786-count-the-number-of-consistent-strings
2163-kth-distinct-string-in-an-array
2300-construct-string-with-repeat-limit
2331-intersection-of-multiple-arrays
2494-sum-of-prefix-scores-of-strings
3267-find-longest-special-substring-that-occurs-thrice-i
3276-minimum-number-of-pushes-to-type-word-ii

Greedy

0179-largest-number
0632-smallest-range-covering-elements-from-k-lists
0670-maximum-swap
0780-max-chunks-to-make-sorted
0957-minimum-add-to-make-parentheses-valid
1304-longest-happy-string
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1711-find-valid-matrix-given-row-and-column-sums
1766-minimum-number-of-removals-to-make-mountain-array
1917-maximum-average-pass-ratio
2089-maximum-matrix-sum
2095-minimum-number-of-swaps-to-make-the-string-balanced
2300-construct-string-with-repeat-limit
2488-divide-intervals-into-minimum-number-of-groups
2616-maximal-score-after-applying-k-operations
2640-maximum-number-of-integers-to-choose-from-a-range-i
2716-prime-subtraction-operation
2720-minimize-the-maximum-difference-of-pairs
3195-separate-black-and-white-balls
3276-minimum-number-of-pushes-to-type-word-ii

Math

0089-gray-code
0202-happy-number
0241-different-ways-to-add-parentheses
0264-ugly-number-ii
0273-integer-to-english-words
0564-find-the-closest-palindrome
0592-fraction-addition-and-subtraction
0650-2-keys-keyboard
0670-maximum-swap
0870-magic-squares-in-grid
1013-fibonacci-number
1240-stone-game-ii
1642-water-bottles
1951-find-the-winner-of-the-circular-game
2155-find-missing-observations
2645-pass-the-pillow
2716-prime-subtraction-operation
2903-insert-greatest-common-divisors-in-linked-list
3555-final-array-state-after-k-multiplication-operations-i

Backtracking

0040-combination-sum-ii
0089-gray-code
0494-target-sum
1715-split-a-string-into-the-max-number-of-unique-substrings
2170-count-number-of-maximum-bitwise-or-subsets

Bit Manipulation

0089-gray-code
0461-hamming-distance
0476-number-complement
1054-complement-of-base-10-integer
1435-xor-queries-of-a-subarray
1786-count-the-number-of-consistent-strings
2170-count-number-of-maximum-bitwise-or-subsets
2323-minimum-bit-flips-to-convert-number
2503-longest-subarray-with-maximum-bitwise-and
3291-find-if-array-can-be-sorted
3380-shortest-subarray-with-or-at-least-k-ii

Linked List

0025-reverse-nodes-in-k-group
0083-remove-duplicates-from-sorted-list
0142-linked-list-cycle-ii
0206-reverse-linked-list
0432-all-oone-data-structure
0725-split-linked-list-in-parts
0859-design-circular-deque
0908-middle-of-the-linked-list
1484-linked-list-in-binary-tree
2182-find-the-minimum-and-maximum-number-of-nodes-between-critical-points
2411-spiral-matrix-iv
2903-insert-greatest-common-divisors-in-linked-list
3501-delete-nodes-from-linked-list-present-in-array

Simulation

0054-spiral-matrix
0592-fraction-addition-and-subtraction
0682-baseball-game
0874-backspace-string-compare
0906-walking-robot-simulation
1642-water-bottles
1803-average-waiting-time
1951-find-the-winner-of-the-circular-game
2006-find-the-student-that-will-replace-the-chalk
2076-sum-of-digits-of-string-after-convert
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2232-adding-spaces-to-a-string
2343-count-unguarded-cells-in-the-grid
2411-spiral-matrix-iv
2645-pass-the-pillow
2692-take-gifts-from-the-richest-pile
2800-minimum-string-length-after-removing-substrings
2846-robot-collisions
3555-final-array-state-after-k-multiplication-operations-i

Recursion

0025-reverse-nodes-in-k-group
0206-reverse-linked-list
0241-different-ways-to-add-parentheses
0273-integer-to-english-words
1013-fibonacci-number
1197-parsing-a-boolean-expression
1951-find-the-winner-of-the-circular-game

Queue

0859-design-circular-deque
1951-find-the-winner-of-the-circular-game
2868-continuous-subarrays

String

0179-largest-number
0214-shortest-palindrome
0241-different-ways-to-add-parentheses
0273-integer-to-english-words
0564-find-the-closest-palindrome
0567-permutation-in-string
0592-fraction-addition-and-subtraction
0664-strange-printer
0726-number-of-atoms
0812-rotate-string
0874-backspace-string-compare
0920-uncommon-words-from-two-sentences
0957-minimum-add-to-make-parentheses-valid
1197-parsing-a-boolean-expression
1298-reverse-substrings-between-each-pair-of-parentheses
1302-delete-characters-to-make-fancy-string
1304-longest-happy-string
1350-remove-sub-folders-from-the-filesystem
1715-split-a-string-into-the-max-number-of-unique-substrings
1720-crawler-log-folder
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1756-minimum-deletions-to-make-string-balanced
1786-count-the-number-of-consistent-strings
1923-sentence-similarity-iii
2076-sum-of-digits-of-string-after-convert
2095-minimum-number-of-swaps-to-make-the-string-balanced
2163-kth-distinct-string-in-an-array
2217-step-by-step-directions-from-a-binary-tree-node-to-another
2232-adding-spaces-to-a-string
2300-construct-string-with-repeat-limit
2414-move-pieces-to-obtain-a-string
2494-sum-of-prefix-scores-of-strings
2502-sort-the-people
2580-circular-sentence
2599-take-k-of-each-character-from-left-and-right
2727-number-of-senior-citizens
2755-extra-characters-in-a-string
2800-minimum-string-length-after-removing-substrings
3018-make-string-a-subsequence-using-cyclic-increments
3174-minimum-number-of-changes-to-make-binary-string-beautiful
3195-separate-black-and-white-balls
3267-find-longest-special-substring-that-occurs-thrice-i
3276-minimum-number-of-pushes-to-type-word-ii
3329-find-the-length-of-the-longest-common-prefix
3451-string-compression-iii

Stack

0084-largest-rectangle-in-histogram
0145-binary-tree-postorder-traversal
0682-baseball-game
0726-number-of-atoms
0776-n-ary-tree-postorder-traversal
0780-max-chunks-to-make-sorted
0874-backspace-string-compare
0957-minimum-add-to-make-parentheses-valid
1002-maximum-width-ramp
1197-parsing-a-boolean-expression
1298-reverse-substrings-between-each-pair-of-parentheses
1497-design-a-stack-with-increment-operation
1570-final-prices-with-a-special-discount-in-a-shop
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1720-crawler-log-folder
1756-minimum-deletions-to-make-string-balanced
2095-minimum-number-of-swaps-to-make-the-string-balanced
2800-minimum-string-length-after-removing-substrings
2846-robot-collisions
3181-find-building-where-alice-and-bob-can-meet

Interactive

0278-first-bad-version

Matrix

0054-spiral-matrix
0787-sliding-puzzle
0870-magic-squares-in-grid
0999-regions-cut-by-slashes
1147-flip-columns-for-maximum-number-of-equal-rows
1402-count-square-submatrices-with-all-ones
1496-lucky-numbers-in-a-matrix
1691-minimum-number-of-days-to-disconnect-island
1711-find-valid-matrix-given-row-and-column-sums
1972-rotating-the-box
2035-count-sub-islands
2089-maximum-matrix-sum
2132-convert-1d-array-into-2d-array
2343-count-unguarded-cells-in-the-grid
2375-minimum-obstacle-removal-to-reach-corner
2411-spiral-matrix-iv
2472-build-a-matrix-with-conditions
2711-minimum-time-to-visit-a-cell-in-a-grid
2794-maximum-number-of-moves-in-a-grid

Divide and Conquer

0948-sort-an-array

Heap (Priority Queue)

0264-ugly-number-ii
0632-smallest-range-covering-elements-from-k-lists
0948-sort-an-array
1304-longest-happy-string
1325-path-with-maximum-probability
1917-maximum-average-pass-ratio
2054-the-number-of-the-smallest-unoccupied-chair
2164-two-best-non-overlapping-events
2300-construct-string-with-repeat-limit
2375-minimum-obstacle-removal-to-reach-corner
2488-divide-intervals-into-minimum-number-of-groups
2616-maximal-score-after-applying-k-operations
2692-take-gifts-from-the-richest-pile
2711-minimum-time-to-visit-a-cell-in-a-grid
2803-modify-graph-edge-weights
2868-continuous-subarrays
3181-find-building-where-alice-and-bob-can-meet
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

Dynamic Programming

0241-different-ways-to-add-parentheses
0264-ugly-number-ii
0494-target-sum
0650-2-keys-keyboard
0664-strange-printer
1013-fibonacci-number
1025-minimum-cost-for-tickets
1063-best-sightseeing-pair
1196-filling-bookcase-shelves
1240-stone-game-ii
1402-count-square-submatrices-with-all-ones
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1511-count-number-of-teams
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1756-minimum-deletions-to-make-string-balanced
1766-minimum-number-of-removals-to-make-mountain-array
2067-maximum-number-of-points-with-cost
2164-two-best-non-overlapping-events
2554-minimum-total-distance-traveled
2562-count-ways-to-build-good-strings
2586-longest-square-streak-in-an-array
2755-extra-characters-in-a-string
2794-maximum-number-of-moves-in-a-grid

Shortest Path

1325-path-with-maximum-probability
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
2171-second-minimum-time-to-reach-destination
2375-minimum-obstacle-removal-to-reach-corner
2711-minimum-time-to-visit-a-cell-in-a-grid
2803-modify-graph-edge-weights

Binary Indexed Tree

1511-count-number-of-teams
3181-find-building-where-alice-and-bob-can-meet

Union Find

0999-regions-cut-by-slashes
2035-count-sub-islands

Strongly Connected Component

1691-minimum-number-of-days-to-disconnect-island

Prefix Sum

1240-stone-game-ii
1435-xor-queries-of-a-subarray
1694-make-sum-divisible-by-p
2006-find-the-student-that-will-replace-the-chalk
2488-divide-intervals-into-minimum-number-of-groups
3427-special-array-ii

Game Theory

1240-stone-game-ii

Number Theory

2716-prime-subtraction-operation
2903-insert-greatest-common-divisors-in-linked-list

Memoization

0241-different-ways-to-add-parentheses
1013-fibonacci-number

Brainteaser

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

Rolling Hash

0214-shortest-palindrome

String Matching

0214-shortest-palindrome
0812-rotate-string

Hash Function

0214-shortest-palindrome

Trie

0386-lexicographical-numbers
0440-k-th-smallest-in-lexicographical-order
1350-remove-sub-folders-from-the-filesystem
2494-sum-of-prefix-scores-of-strings
2755-extra-characters-in-a-string
3329-find-the-length-of-the-longest-common-prefix

Design

0432-all-oone-data-structure
0729-my-calendar-i
0859-design-circular-deque
1497-design-a-stack-with-increment-operation

Segment Tree

0729-my-calendar-i
3181-find-building-where-alice-and-bob-can-meet

Ordered Set

0729-my-calendar-i
2868-continuous-subarrays

Doubly-Linked List

0432-all-oone-data-structure

Monotonic Stack

0084-largest-rectangle-in-histogram
0780-max-chunks-to-make-sorted
1002-maximum-width-ramp
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

Enumeration

2170-count-number-of-maximum-bitwise-or-subsets

Eulerian Circuit

2201-valid-arrangement-of-pairs

Monotonic Queue

2868-continuous-subarrays