DSA_Problems

LeetCode Topics

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0014-longest-common-prefix
0015-3sum
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0039-combination-sum
0040-combination-sum-ii
0042-trapping-rain-water
0045-jump-game-ii
0046-permutations
0048-rotate-image
0053-maximum-subarray
0054-spiral-matrix
0055-jump-game
0056-merge-intervals
0057-insert-interval
0066-plus-one
0073-set-matrix-zeroes
0075-sort-colors
0078-subsets
0081-search-in-rotated-sorted-array-ii
0088-merge-sorted-array
0090-subsets-ii
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0135-candy
0136-single-number
0137-single-number-ii
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0189-rotate-array
0198-house-robber
0209-minimum-size-subarray-sum
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0229-majority-element-ii
0238-product-of-array-except-self
0240-search-a-2d-matrix-ii
0260-single-number-iii
0268-missing-number
0283-move-zeroes
0287-find-the-duplicate-number
0322-coin-change
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0448-find-all-numbers-disappeared-in-an-array
0455-assign-cookies
0496-next-greater-element-i
0503-next-greater-element-ii
0540-single-element-in-a-sorted-array
0560-subarray-sum-equals-k
0717-1-bit-and-2-bit-characters
0724-find-pivot-index
0735-asteroid-collision
0745-find-smallest-letter-greater-than-target
0890-lemonade-change
0917-boats-to-save-people
0941-sort-array-by-parity
0944-delete-columns-to-make-sorted
0948-sort-an-array
0966-binary-subarrays-with-sum
1001-n-repeated-element-in-size-2n-array
1008-construct-binary-search-tree-from-preorder-traversal
1018-binary-prefix-divisible-by-5
1019-squares-of-a-sorted-array
1034-subarrays-with-k-different-integers
1046-max-consecutive-ones-iii
1047-maximize-sum-of-array-after-k-negations
1051-height-checker
1056-capacity-to-ship-packages-within-d-days
1127-last-stone-weight
1231-replace-elements-with-greatest-element-on-right-side
1319-unique-number-of-occurrences
1370-count-number-of-nice-subarrays
1408-find-the-smallest-divisor-given-a-threshold
1421-find-numbers-with-even-number-of-digits
1426-find-n-unique-integers-sum-up-to-zero
1482-how-many-numbers-are-smaller-than-the-current-number
1510-find-lucky-integer-in-an-array
1548-check-if-all-1s-are-at-least-length-k-places-away
1605-minimum-number-of-days-to-make-m-bouquets
1646-kth-missing-positive-number
1677-matrix-diagonal-sum
1700-minimum-time-to-make-rope-colorful
1769-minimum-number-of-operations-to-move-all-balls-to-each-box
1833-find-the-highest-altitude
1848-sum-of-unique-elements
1878-check-if-array-is-sorted-and-rotated
1938-minimum-operations-to-make-the-array-increasing
1951-find-the-winner-of-the-circular-game
1993-sum-of-all-subset-xor-totals
2058-concatenation-of-array
2106-find-greatest-common-divisor-of-array
2110-number-of-smooth-descent-periods-of-a-stock
2137-final-value-of-variable-after-performing-operations
2210-find-target-indices-after-sorting-array
2219-maximum-number-of-words-found-in-sentences
2227-sum-of-subarray-ranges
2254-check-if-every-row-and-column-contains-all-numbers
2269-count-elements-with-strictly-smaller-and-greater-elements
2271-rearrange-array-elements-by-sign
2274-keep-multiplying-found-values-by-two
2320-find-all-k-distant-indices-in-an-array
2324-find-triangular-sum-of-an-array
2331-intersection-of-multiple-arrays
2358-number-of-ways-to-split-array
2432-number-of-zero-filled-subarrays
2525-count-number-of-distinct-integers-after-reverse-operations
2624-difference-between-element-sum-and-digit-sum-of-an-array
2639-separate-the-digits-in-an-array
2654-count-the-number-of-vowel-strings-in-range
2676-find-the-score-of-all-prefixes-of-an-array
2684-determine-the-winner-of-a-bowling-game
2692-take-gifts-from-the-richest-pile
2694-find-the-maximum-divisibility-score
2712-find-the-maximum-number-of-marked-indices
2722-prime-in-diagonal
2728-sum-in-a-matrix
2737-row-with-maximum-ones
2767-maximum-sum-with-exactly-k-elements
2836-neither-minimum-nor-maximum
2845-find-the-value-of-the-partition
2847-find-maximum-number-of-string-pairs
2872-largest-element-in-an-array-after-merge-operations
2876-number-of-employees-who-met-the-target
2917-count-pairs-whose-sum-is-less-than-target
3165-find-indices-with-index-and-value-difference-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3193-maximum-strong-pair-xor-i
3194-find-words-containing-character
3206-find-common-elements-between-two-arrays
3221-find-the-peaks
3242-count-elements-with-maximum-frequency
3311-ant-on-the-boundary
3330-modify-the-matrix
3331-minimum-operations-to-exceed-threshold-value-i
3334-apple-redistribution-into-boxes
3355-minimum-levels-to-gain-more-points
3367-find-the-sum-of-encrypted-integers
3397-find-the-integer-added-to-array-i
3422-find-the-n-th-value-after-k-seconds
3432-count-partitions-with-even-sum-difference
3446-find-the-number-of-good-pairs-i
3471-minimum-average-of-smallest-and-largest-elements
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3501-delete-nodes-from-linked-list-present-in-array
3528-reach-end-of-array-with-max-score
3581-the-two-sneaky-numbers-of-digitville
3582-find-indices-of-stable-mountains
3606-minimum-element-after-replacement-with-digit-sum
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3778-transform-array-by-parity
3846-minimum-operations-to-make-array-sum-divisible-by-k
3869-smallest-index-with-digit-sum-equal-to-index

Two Pointers

0015-3sum
0018-4sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0031-next-permutation
0042-trapping-rain-water
0075-sort-colors
0088-merge-sorted-array
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0165-compare-version-numbers
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0234-palindrome-linked-list
0283-move-zeroes
0287-find-the-duplicate-number
0349-intersection-of-two-arrays
0443-string-compression
0455-assign-cookies
0633-sum-of-square-numbers
0908-middle-of-the-linked-list
0917-boats-to-save-people
0941-sort-array-by-parity
1019-squares-of-a-sorted-array
2216-delete-the-middle-node-of-a-linked-list
2271-rearrange-array-elements-by-sign
2320-find-all-k-distant-indices-in-an-array
2481-strictly-palindromic-number
2712-find-the-maximum-number-of-marked-indices
2917-count-pairs-whose-sum-is-less-than-target
3165-find-indices-with-index-and-value-difference-i
3471-minimum-average-of-smallest-and-largest-elements

Sorting

0015-3sum
0018-4sum
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0148-sort-list
0169-majority-element
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0229-majority-element-ii
0268-missing-number
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0389-find-the-difference
0435-non-overlapping-intervals
0455-assign-cookies
0917-boats-to-save-people
0941-sort-array-by-parity
0948-sort-an-array
0987-vertical-order-traversal-of-a-binary-tree
1019-squares-of-a-sorted-array
1047-maximize-sum-of-array-after-k-negations
1051-height-checker
1482-how-many-numbers-are-smaller-than-the-current-number
2210-find-target-indices-after-sorting-array
2269-count-elements-with-strictly-smaller-and-greater-elements
2274-keep-multiplying-found-values-by-two
2331-intersection-of-multiple-arrays
2712-find-the-maximum-number-of-marked-indices
2728-sum-in-a-matrix
2836-neither-minimum-nor-maximum
2845-find-the-value-of-the-partition
2887-sort-vowels-in-a-string
2917-count-pairs-whose-sum-is-less-than-target
3334-apple-redistribution-into-boxes
3471-minimum-average-of-smallest-and-largest-elements
3778-transform-array-by-parity

Math

0002-add-two-numbers
0007-reverse-integer
0029-divide-two-integers
0048-rotate-image
0050-powx-n
0066-plus-one
0070-climbing-stairs
0171-excel-sheet-column-number
0189-rotate-array
0231-power-of-two
0268-missing-number
0319-bulb-switcher
0342-power-of-four
0367-valid-perfect-square
0507-perfect-number
0633-sum-of-square-numbers
1015-smallest-integer-divisible-by-k
1303-minimum-moves-to-reach-target-score
1370-count-number-of-nice-subarrays
1411-convert-binary-number-in-a-linked-list-to-integer
1421-find-numbers-with-even-number-of-digits
1426-find-n-unique-integers-sum-up-to-zero
1440-convert-integer-to-the-sum-of-two-no-zero-integers
1444-number-of-steps-to-reduce-a-number-to-zero
1448-maximum-69-number
1523-count-odd-numbers-in-an-interval-range
1642-water-bottles
1817-calculate-money-in-leetcode-bank
1951-find-the-winner-of-the-circular-game
1965-sum-of-digits-in-base-k
1993-sum-of-all-subset-xor-totals
2032-largest-odd-number-in-string
2106-find-greatest-common-divisor-of-array
2110-number-of-smooth-descent-periods-of-a-stock
2288-count-operations-to-obtain-zero
2298-count-integers-with-even-digit-sum
2324-find-triangular-sum-of-an-array
2383-add-two-integers
2432-number-of-zero-filled-subarrays
2481-strictly-palindromic-number
2525-count-number-of-distinct-integers-after-reverse-operations
2608-count-the-digits-that-divide-a-number
2624-difference-between-element-sum-and-digit-sum-of-an-array
2649-count-total-number-of-colored-cells
2722-prime-in-diagonal
2824-check-if-the-number-is-fascinating
2864-maximum-odd-binary-number
3172-divisible-and-non-divisible-sums-difference
3367-find-the-sum-of-encrypted-integers
3371-harshad-number
3422-find-the-n-th-value-after-k-seconds
3432-count-partitions-with-even-sum-difference
3450-find-the-child-who-has-the-ball-after-k-seconds
3462-vowels-game-in-a-string
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3553-check-if-two-chessboard-squares-have-the-same-color
3581-the-two-sneaky-numbers-of-digitville
3606-minimum-element-after-replacement-with-digit-sum
3626-smallest-divisible-digit-product-i
3676-smallest-number-with-all-set-bits
3768-check-if-digits-are-equal-in-string-after-operations-i
3817-maximum-containers-on-a-ship
3830-find-closest-person
3846-minimum-operations-to-make-array-sum-divisible-by-k
3869-smallest-index-with-digit-sum-equal-to-index
3918-check-divisibility-by-digit-sum-and-product

Recursion

0002-add-two-numbers
0024-swap-nodes-in-pairs
0050-powx-n
0203-remove-linked-list-elements
0206-reverse-linked-list
0231-power-of-two
0234-palindrome-linked-list
0342-power-of-four
1951-find-the-winner-of-the-circular-game

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0073-set-matrix-zeroes
0076-minimum-window-substring
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0160-intersection-of-two-linked-lists
0169-majority-element
0217-contains-duplicate
0229-majority-element-ii
0268-missing-number
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0389-find-the-difference
0424-longest-repeating-character-replacement
0448-find-all-numbers-disappeared-in-an-array
0496-next-greater-element-i
0560-subarray-sum-equals-k
0782-jewels-and-stones
0863-all-nodes-distance-k-in-binary-tree
0966-binary-subarrays-with-sum
0987-vertical-order-traversal-of-a-binary-tree
1001-n-repeated-element-in-size-2n-array
1015-smallest-integer-divisible-by-k
1034-subarrays-with-k-different-integers
1264-maximum-number-of-words-you-can-type
1319-unique-number-of-occurrences
1370-count-number-of-nice-subarrays
1482-how-many-numbers-are-smaller-than-the-current-number
1510-find-lucky-integer-in-an-array
1848-sum-of-unique-elements
1960-check-if-the-sentence-is-pangram
2254-check-if-every-row-and-column-contains-all-numbers
2274-keep-multiplying-found-values-by-two
2331-intersection-of-multiple-arrays
2525-count-number-of-distinct-integers-after-reverse-operations
2824-check-if-the-number-is-fascinating
2847-find-maximum-number-of-string-pairs
3193-maximum-strong-pair-xor-i
3206-find-common-elements-between-two-arrays
3242-count-elements-with-maximum-frequency
3446-find-the-number-of-good-pairs-i
3501-delete-nodes-from-linked-list-present-in-array
3581-the-two-sneaky-numbers-of-digitville
3872-find-most-frequent-vowel-and-consonant

Divide and Conquer

0004-median-of-two-sorted-arrays
0053-maximum-subarray
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0148-sort-list
0169-majority-element
0191-number-of-1-bits
0215-kth-largest-element-in-an-array
0240-search-a-2d-matrix-ii
0347-top-k-frequent-elements
0948-sort-an-array

Counting

0169-majority-element
0229-majority-element-ii
0347-top-k-frequent-elements
1034-subarrays-with-k-different-integers
1510-find-lucky-integer-in-an-array
1848-sum-of-unique-elements
2269-count-elements-with-strictly-smaller-and-greater-elements
2331-intersection-of-multiple-arrays
2525-count-number-of-distinct-integers-after-reverse-operations
2654-count-the-number-of-vowel-strings-in-range
3019-furthest-point-from-origin
3242-count-elements-with-maximum-frequency
3778-transform-array-by-parity
3872-find-most-frequent-vowel-and-consonant

Dynamic Programming

0022-generate-parentheses
0042-trapping-rain-water
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0070-climbing-stairs
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0124-binary-tree-maximum-path-sum
0152-maximum-product-subarray
0198-house-robber
0322-coin-change
0338-counting-bits
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0678-valid-parenthesis-string
1700-minimum-time-to-make-rope-colorful
2110-number-of-smooth-descent-periods-of-a-stock

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0081-search-in-rotated-sorted-array-ii
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0222-count-complete-tree-nodes
0240-search-a-2d-matrix-ii
0268-missing-number
0287-find-the-duplicate-number
0349-intersection-of-two-arrays
0367-valid-perfect-square
0374-guess-number-higher-or-lower
0540-single-element-in-a-sorted-array
0633-sum-of-square-numbers
0745-find-smallest-letter-greater-than-target
1046-max-consecutive-ones-iii
1056-capacity-to-ship-packages-within-d-days
1408-find-the-smallest-divisor-given-a-threshold
1605-minimum-number-of-days-to-make-m-bouquets
1646-kth-missing-positive-number
2210-find-target-indices-after-sorting-array
2712-find-the-maximum-number-of-marked-indices
2917-count-pairs-whose-sum-is-less-than-target

Simulation

0054-spiral-matrix
0657-robot-return-to-origin
0735-asteroid-collision
1642-water-bottles
1951-find-the-winner-of-the-circular-game
2021-remove-all-occurrences-of-a-substring
2058-concatenation-of-array
2137-final-value-of-variable-after-performing-operations
2271-rearrange-array-elements-by-sign
2274-keep-multiplying-found-values-by-two
2288-count-operations-to-obtain-zero
2298-count-integers-with-even-digit-sum
2324-find-triangular-sum-of-an-array
2639-separate-the-digits-in-an-array
2684-determine-the-winner-of-a-bowling-game
2692-take-gifts-from-the-richest-pile
2728-sum-in-a-matrix
2847-find-maximum-number-of-string-pairs
3311-ant-on-the-boundary
3422-find-the-n-th-value-after-k-seconds
3426-minimum-number-of-chairs-in-a-waiting-room
3450-find-the-child-who-has-the-ball-after-k-seconds
3768-check-if-digits-are-equal-in-string-after-operations-i

Matrix

0048-rotate-image
0054-spiral-matrix
0073-set-matrix-zeroes
0240-search-a-2d-matrix-ii
1677-matrix-diagonal-sum
2254-check-if-every-row-and-column-contains-all-numbers
2722-prime-in-diagonal
2728-sum-in-a-matrix
2737-row-with-maximum-ones
3330-modify-the-matrix

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0024-swap-nodes-in-pairs
0083-remove-duplicates-from-sorted-list
0114-flatten-binary-tree-to-linked-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0148-sort-list
0160-intersection-of-two-linked-lists
0203-remove-linked-list-elements
0206-reverse-linked-list
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0328-odd-even-linked-list
0908-middle-of-the-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer
2216-delete-the-middle-node-of-a-linked-list
3501-delete-nodes-from-linked-list-present-in-array

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0560-subarray-sum-equals-k
0724-find-pivot-index
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1769-minimum-number-of-operations-to-move-all-balls-to-each-box
1833-find-the-highest-altitude
2358-number-of-ways-to-split-array
2676-find-the-score-of-all-prefixes-of-an-array
3311-ant-on-the-boundary
3355-minimum-levels-to-gain-more-points
3422-find-the-n-th-value-after-k-seconds
3432-count-partitions-with-even-sum-difference

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
0948-sort-an-array
1127-last-stone-weight
2692-take-gifts-from-the-richest-pile
2728-sum-in-a-matrix

Merge Sort

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

Bucket Sort

0347-top-k-frequent-elements
0948-sort-an-array

Radix Sort

0948-sort-an-array

Counting Sort

0948-sort-an-array
1051-height-checker
1482-how-many-numbers-are-smaller-than-the-current-number

Stack

0020-valid-parentheses
0042-trapping-rain-water
0094-binary-tree-inorder-traversal
0114-flatten-binary-tree-to-linked-list
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0155-min-stack
0173-binary-search-tree-iterator
0234-palindrome-linked-list
0402-remove-k-digits
0496-next-greater-element-i
0503-next-greater-element-ii
0678-valid-parenthesis-string
0735-asteroid-collision
1008-construct-binary-search-tree-from-preorder-traversal
2021-remove-all-occurrences-of-a-substring
2227-sum-of-subarray-ranges

Memoization

0070-climbing-stairs

Backtracking

0022-generate-parentheses
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0078-subsets
0090-subsets-ii
1993-sum-of-all-subset-xor-totals

Bit Manipulation

0029-divide-two-integers
0078-subsets
0090-subsets-ii
0136-single-number
0137-single-number-ii
0191-number-of-1-bits
0222-count-complete-tree-nodes
0231-power-of-two
0260-single-number-iii
0268-missing-number
0287-find-the-duplicate-number
0338-counting-bits
0342-power-of-four
0389-find-the-difference
1018-binary-prefix-divisible-by-5
1444-number-of-steps-to-reduce-a-number-to-zero
1993-sum-of-all-subset-xor-totals
2323-minimum-bit-flips-to-convert-number
3193-maximum-strong-pair-xor-i
3676-smallest-number-with-all-set-bits

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
0199-binary-tree-right-side-view
0226-invert-binary-tree
0297-serialize-and-deserialize-binary-tree
0322-coin-change
0662-maximum-width-of-binary-tree
0863-all-nodes-distance-k-in-binary-tree
0987-vertical-order-traversal-of-a-binary-tree

String

0003-longest-substring-without-repeating-characters
0014-longest-common-prefix
0020-valid-parentheses
0022-generate-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0058-length-of-last-word
0076-minimum-window-substring
0151-reverse-words-in-a-string
0165-compare-version-numbers
0171-excel-sheet-column-number
0297-serialize-and-deserialize-binary-tree
0389-find-the-difference
0402-remove-k-digits
0424-longest-repeating-character-replacement
0443-string-compression
0657-robot-return-to-origin
0678-valid-parenthesis-string
0782-jewels-and-stones
0812-rotate-string
0944-delete-columns-to-make-sorted
1205-defanging-an-ip-address
1264-maximum-number-of-words-you-can-type
1700-minimum-time-to-make-rope-colorful
1769-minimum-number-of-operations-to-move-all-balls-to-each-box
1960-check-if-the-sentence-is-pangram
2021-remove-all-occurrences-of-a-substring
2032-largest-odd-number-in-string
2137-final-value-of-variable-after-performing-operations
2219-maximum-number-of-words-found-in-sentences
2243-check-if-all-as-appears-before-all-bs
2654-count-the-number-of-vowel-strings-in-range
2847-find-maximum-number-of-string-pairs
2864-maximum-odd-binary-number
2887-sort-vowels-in-a-string
3019-furthest-point-from-origin
3194-find-words-containing-character
3379-score-of-a-string
3426-minimum-number-of-chairs-in-a-waiting-room
3462-vowels-game-in-a-string
3553-check-if-two-chessboard-squares-have-the-same-color
3636-check-balanced-string
3768-check-if-digits-are-equal-in-string-after-operations-i
3872-find-most-frequent-vowel-and-consonant

Design

0146-lru-cache
0155-min-stack
0173-binary-search-tree-iterator
0297-serialize-and-deserialize-binary-tree

Greedy

0045-jump-game-ii
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0135-candy
0402-remove-k-digits
0435-non-overlapping-intervals
0455-assign-cookies
0678-valid-parenthesis-string
0890-lemonade-change
0917-boats-to-save-people
1047-maximize-sum-of-array-after-k-negations
1303-minimum-moves-to-reach-target-score
1448-maximum-69-number
1700-minimum-time-to-make-rope-colorful
1938-minimum-operations-to-make-the-array-increasing
2032-largest-odd-number-in-string
2712-find-the-maximum-number-of-marked-indices
2767-maximum-sum-with-exactly-k-elements
2864-maximum-odd-binary-number
2872-largest-element-in-an-array-after-merge-operations
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3334-apple-redistribution-into-boxes
3528-reach-end-of-array-with-max-score

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
0812-rotate-string

Monotonic Stack

0042-trapping-rain-water
0402-remove-k-digits
0496-next-greater-element-i
0503-next-greater-element-ii
1008-construct-binary-search-tree-from-preorder-traversal
2227-sum-of-subarray-ranges

Number Theory

2106-find-greatest-common-divisor-of-array
2722-prime-in-diagonal
3768-check-if-digits-are-equal-in-string-after-operations-i

Brainteaser

0319-bulb-switcher
2481-strictly-palindromic-number
3462-vowels-game-in-a-string

Game Theory

3462-vowels-game-in-a-string

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0209-minimum-size-subarray-sum
0424-longest-repeating-character-replacement
0966-binary-subarrays-with-sum
1034-subarrays-with-k-different-integers
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
3193-maximum-strong-pair-xor-i

Enumeration

1993-sum-of-all-subset-xor-totals
3221-find-the-peaks
3626-smallest-divisible-digit-product-i

Combinatorics

1993-sum-of-all-subset-xor-totals
2324-find-triangular-sum-of-an-array
3422-find-the-n-th-value-after-k-seconds
3768-check-if-digits-are-equal-in-string-after-operations-i

Quickselect

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

Trie

0014-longest-common-prefix
3193-maximum-strong-pair-xor-i

Graph

1916-find-center-of-star-graph

Doubly-Linked List

0146-lru-cache

Queue

1951-find-the-winner-of-the-circular-game

Tree

0094-binary-tree-inorder-traversal
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
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0450-delete-node-in-a-bst
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0700-search-in-a-binary-search-tree
0701-insert-into-a-binary-search-tree
0863-all-nodes-distance-k-in-binary-tree
0987-vertical-order-traversal-of-a-binary-tree
1008-construct-binary-search-tree-from-preorder-traversal

Depth-First Search

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0863-all-nodes-distance-k-in-binary-tree
0987-vertical-order-traversal-of-a-binary-tree

Binary Tree

0094-binary-tree-inorder-traversal
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
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0450-delete-node-in-a-bst
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0700-search-in-a-binary-search-tree
0701-insert-into-a-binary-search-tree
0863-all-nodes-distance-k-in-binary-tree
0987-vertical-order-traversal-of-a-binary-tree
1008-construct-binary-search-tree-from-preorder-traversal

Binary Search Tree

0098-validate-binary-search-tree
0173-binary-search-tree-iterator
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0450-delete-node-in-a-bst
0700-search-in-a-binary-search-tree
0701-insert-into-a-binary-search-tree
1008-construct-binary-search-tree-from-preorder-traversal

Iterator

0173-binary-search-tree-iterator

Interactive

0374-guess-number-higher-or-lower