Leetcode_Solution

LeetCode Topics

Array

0011-container-with-most-water
0015-3sum
0027-remove-element
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0042-trapping-rain-water
0045-jump-game-ii
0075-sort-colors
0078-subsets
0080-remove-duplicates-from-sorted-array-ii
0081-search-in-rotated-sorted-array-ii
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0118-pascals-triangle
0119-pascals-triangle-ii
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0135-candy
0136-single-number
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0169-majority-element
0219-contains-duplicate-ii
0228-summary-ranges
0238-product-of-array-except-self
0274-h-index
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0414-third-maximum-number
0495-teemo-attacking
0496-next-greater-element-i
0503-next-greater-element-ii
0540-single-element-in-a-sorted-array
0561-array-partition
0575-distribute-candies
0594-longest-harmonious-subsequence
0682-baseball-game
0724-find-pivot-index
0735-asteroid-collision
0739-daily-temperatures
0792-binary-search
0797-rabbits-in-forest
0890-lemonade-change
0907-koko-eating-bananas
0932-monotonic-array
0934-bitwise-ors-of-subarrays
0940-fruit-into-baskets
0943-sum-of-subarray-minimums
0945-snakes-and-ladders
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1049-minimum-domino-rotations-for-equal-row
1056-capacity-to-ship-packages-within-d-days
1227-number-of-equivalent-domino-pairs
1350-remove-sub-folders-from-the-filesystem
1370-count-number-of-nice-subarrays
1408-find-the-smallest-divisor-given-a-threshold
1421-find-numbers-with-even-number-of-digits
1424-maximum-candies-you-can-get-from-boxes
1478-maximum-number-of-events-that-can-be-attended
1538-maximum-points-you-can-obtain-from-cards
1580-shuffle-the-array
1586-longest-subarray-of-1s-after-deleting-one-element
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1755-defuse-the-bomb
1802-number-of-students-unable-to-eat-lunch
1813-maximum-erasure-value
1833-find-the-highest-altitude
1839-decode-xored-array
1851-maximum-number-of-events-that-can-be-attended-ii
2048-build-array-from-permutation
2079-delete-duplicate-folders-in-system
2150-kth-smallest-product-of-two-sorted-arrays
2170-count-number-of-maximum-bitwise-or-subsets
2180-maximum-number-of-tasks-you-can-assign
2204-find-subsequence-of-length-k-with-the-largest-sum
2227-sum-of-subarray-ranges
2237-longest-palindrome-by-concatenating-two-letter-words
2249-count-the-hidden-sequences
2267-minimum-difference-in-sums-after-removal-of-elements
2277-count-equal-and-divisible-pairs-in-an-array
2280-count-good-triplets-in-an-array
2308-divide-array-into-equal-pairs
2316-count-hills-and-valleys-in-an-array
2320-find-all-k-distant-indices-in-an-array
2387-partition-array-such-that-maximum-difference-is-k
2394-count-subarrays-with-score-less-than-k
2479-meeting-rooms-iii
2497-maximum-matching-of-players-with-trainers
2498-smallest-subarrays-with-maximum-bitwise-or
2503-longest-subarray-with-maximum-bitwise-and
2527-count-subarrays-with-fixed-bounds
2529-range-product-queries-of-powers
2551-apply-operations-to-an-array
2626-count-the-number-of-good-subarrays
2689-rearranging-fruits
2699-count-the-number-of-fair-pairs
2720-minimize-the-maximum-difference-of-pairs
2856-count-complete-subarrays-in-an-array
2915-count-of-interesting-subarrays
3194-find-words-containing-character
3213-count-subarrays-where-max-element-appears-at-least-k-times
3241-divide-array-into-arrays-with-max-difference
3251-maximum-area-of-longest-diagonal-rectangle
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3459-find-the-minimum-area-to-cover-all-ones-ii
3461-find-the-minimum-area-to-cover-all-ones-i
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3648-find-the-maximum-number-of-fruits-collected
3685-count-subarrays-of-length-three-with-a-condition
3738-make-array-non-decreasing
3741-reschedule-meetings-for-maximum-free-time-ii
3743-reschedule-meetings-for-maximum-free-time-i
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3748-sort-matrix-by-diagonals
3789-maximize-subarrays-after-removing-one-conflicting-pair

Hash Table

0003-longest-substring-without-repeating-characters
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0169-majority-element
0202-happy-number
0205-isomorphic-strings
0219-contains-duplicate-ii
0242-valid-anagram
0290-word-pattern
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0387-first-unique-character-in-a-string
0424-longest-repeating-character-replacement
0496-next-greater-element-i
0575-distribute-candies
0594-longest-harmonious-subsequence
0797-rabbits-in-forest
0900-reordered-power-of-2
0940-fruit-into-baskets
0966-binary-subarrays-with-sum
1029-vertical-order-traversal-of-a-binary-tree
1227-number-of-equivalent-domino-pairs
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1500-count-largest-group
1813-maximum-erasure-value
1873-longest-nice-substring
2079-delete-duplicate-folders-in-system
2204-find-subsequence-of-length-k-with-the-largest-sum
2237-longest-palindrome-by-concatenating-two-letter-words
2308-divide-array-into-equal-pairs
2479-meeting-rooms-iii
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2626-count-the-number-of-good-subarrays
2689-rearranging-fruits
2856-count-complete-subarrays-in-an-array
2915-count-of-interesting-subarrays
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes

Sliding Window

0003-longest-substring-without-repeating-characters
0219-contains-duplicate-ii
0424-longest-repeating-character-replacement
0594-longest-harmonious-subsequence
0940-fruit-into-baskets
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1351-replace-the-substring-for-balanced-string
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1538-maximum-points-you-can-obtain-from-cards
1586-longest-subarray-of-1s-after-deleting-one-element
1755-defuse-the-bomb
1813-maximum-erasure-value
1873-longest-nice-substring
2394-count-subarrays-with-score-less-than-k
2498-smallest-subarrays-with-maximum-bitwise-or
2527-count-subarrays-with-fixed-bounds
2626-count-the-number-of-good-subarrays
2856-count-complete-subarrays-in-an-array
3213-count-subarrays-where-max-element-appears-at-least-k-times
3743-reschedule-meetings-for-maximum-free-time-i
3761-maximum-difference-between-even-and-odd-frequency-ii

Binary Search

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
0278-first-bad-version
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0367-valid-perfect-square
0540-single-element-in-a-sorted-array
0792-binary-search
0907-koko-eating-bananas
1046-max-consecutive-ones-iii
1056-capacity-to-ship-packages-within-d-days
1408-find-the-smallest-divisor-given-a-threshold
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1851-maximum-number-of-events-that-can-be-attended-ii
2150-kth-smallest-product-of-two-sorted-arrays
2180-maximum-number-of-tasks-you-can-assign
2280-count-good-triplets-in-an-array
2394-count-subarrays-with-score-less-than-k
2498-smallest-subarrays-with-maximum-bitwise-or
2699-count-the-number-of-fair-pairs
2720-minimize-the-maximum-difference-of-pairs

Divide and Conquer

0148-sort-list
0169-majority-element
1873-longest-nice-substring
2280-count-good-triplets-in-an-array

Binary Indexed Tree

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

Segment Tree

2280-count-good-triplets-in-an-array
3789-maximize-subarrays-after-removing-one-conflicting-pair

Merge Sort

0148-sort-list
2280-count-good-triplets-in-an-array

Ordered Set

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

Two Pointers

0011-container-with-most-water
0015-3sum
0019-remove-nth-node-from-end-of-list
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0042-trapping-rain-water
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0082-remove-duplicates-from-sorted-list-ii
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0202-happy-number
0234-palindrome-linked-list
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0392-is-subsequence
0557-reverse-words-in-a-string-iii
0868-push-dominoes
0874-backspace-string-compare
0908-middle-of-the-linked-list
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2216-delete-the-middle-node-of-a-linked-list
2320-find-all-k-distant-indices-in-an-array
2497-maximum-matching-of-players-with-trainers
2551-apply-operations-to-an-array
2699-count-the-number-of-fair-pairs

String

0003-longest-substring-without-repeating-characters
0008-string-to-integer-atoi
0014-longest-common-prefix
0028-find-the-index-of-the-first-occurrence-in-a-string
0038-count-and-say
0058-length-of-last-word
0151-reverse-words-in-a-string
0168-excel-sheet-column-title
0205-isomorphic-strings
0242-valid-anagram
0290-word-pattern
0387-first-unique-character-in-a-string
0392-is-subsequence
0402-remove-k-digits
0412-fizz-buzz
0415-add-strings
0424-longest-repeating-character-replacement
0557-reverse-words-in-a-string-iii
0678-valid-parenthesis-string
0812-rotate-string
0868-push-dominoes
0874-backspace-string-compare
1058-lexicographically-smallest-equivalent-string
1128-remove-all-adjacent-duplicates-in-string
1302-delete-characters-to-make-fancy-string
1350-remove-sub-folders-from-the-filesystem
1351-replace-the-substring-for-balanced-string
1460-number-of-substrings-containing-all-three-characters
1666-make-the-string-great
1737-maximum-nesting-depth-of-the-parentheses
1873-longest-nice-substring
2032-largest-odd-number-in-string
2079-delete-duplicate-folders-in-system
2140-longest-subsequence-repeated-k-times
2237-longest-palindrome-by-concatenating-two-letter-words
2260-divide-a-string-into-groups-of-size-k
2395-longest-binary-subsequence-less-than-or-equal-to-k
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2800-minimum-string-length-after-removing-substrings
3194-find-words-containing-character
3360-minimum-deletions-to-make-string-k-special
3396-valid-word
3445-lexicographically-minimum-string-after-removing-stars
3617-find-the-original-typed-string-i
3618-find-the-original-typed-string-ii
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes
3761-maximum-difference-between-even-and-odd-frequency-ii

Dynamic Programming

0042-trapping-rain-water
0045-jump-game-ii
0085-maximal-rectangle
0118-pascals-triangle
0119-pascals-triangle-ii
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0124-binary-tree-maximum-path-sum
0392-is-subsequence
0678-valid-parenthesis-string
0826-soup-servings
0868-push-dominoes
0934-bitwise-ors-of-subarrays
0943-sum-of-subarray-minimums
1586-longest-subarray-of-1s-after-deleting-one-element
1851-maximum-number-of-events-that-can-be-attended-ii
2028-the-earliest-and-latest-rounds-where-players-compete
2061-painting-a-grid-with-three-different-colors
2267-minimum-difference-in-sums-after-removal-of-elements
2395-longest-binary-subsequence-less-than-or-equal-to-k
2415-count-the-number-of-ideal-arrays
3307-find-the-maximum-sum-of-node-values
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3618-find-the-original-typed-string-ii
3648-find-the-maximum-number-of-fruits-collected

String Matching

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

Sorting

0015-3sum
0075-sort-colors
0148-sort-list
0169-majority-element
0242-valid-anagram
0274-h-index
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0414-third-maximum-number
0561-array-partition
0594-longest-harmonious-subsequence
0900-reordered-power-of-2
1029-vertical-order-traversal-of-a-binary-tree
1478-maximum-number-of-events-that-can-be-attended
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1851-maximum-number-of-events-that-can-be-attended-ii
2180-maximum-number-of-tasks-you-can-assign
2204-find-subsequence-of-length-k-with-the-largest-sum
2387-partition-array-such-that-maximum-difference-is-k
2479-meeting-rooms-iii
2497-maximum-matching-of-players-with-trainers
2689-rearranging-fruits
2699-count-the-number-of-fair-pairs
3241-divide-array-into-arrays-with-max-difference
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3360-minimum-deletions-to-make-string-k-special
3748-sort-matrix-by-diagonals

Counting

0169-majority-element
0387-first-unique-character-in-a-string
0594-longest-harmonious-subsequence
0900-reordered-power-of-2
1227-number-of-equivalent-domino-pairs
2140-longest-subsequence-repeated-k-times
2237-longest-palindrome-by-concatenating-two-letter-words
2308-divide-array-into-equal-pairs
3360-minimum-deletions-to-make-string-k-special
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes

Math

0009-palindrome-number
0029-divide-two-integers
0050-powx-n
0168-excel-sheet-column-title
0202-happy-number
0231-power-of-two
0258-add-digits
0263-ugly-number
0292-nim-game
0326-power-of-three
0342-power-of-four
0367-valid-perfect-square
0412-fizz-buzz
0415-add-strings
0797-rabbits-in-forest
0826-soup-servings
0900-reordered-power-of-2
1370-count-number-of-nice-subarrays
1411-convert-binary-number-in-a-linked-list-to-integer
1421-find-numbers-with-even-number-of-digits
1500-count-largest-group
2032-largest-odd-number-in-string
2202-sum-of-k-mirror-numbers
2415-count-the-number-of-ideal-arrays
2704-maximum-difference-by-remapping-a-digit
3172-divisible-and-non-divisible-sums-difference
3201-distribute-candies-among-children-ii
3321-type-of-triangle
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii
3754-maximum-manhattan-distance-after-k-changes

Greedy

0011-container-with-most-water
0045-jump-game-ii
0122-best-time-to-buy-and-sell-stock-ii
0135-candy
0402-remove-k-digits
0561-array-partition
0678-valid-parenthesis-string
0797-rabbits-in-forest
0890-lemonade-change
1049-minimum-domino-rotations-for-equal-row
1478-maximum-number-of-events-that-can-be-attended
2032-largest-odd-number-in-string
2140-longest-subsequence-repeated-k-times
2180-maximum-number-of-tasks-you-can-assign
2237-longest-palindrome-by-concatenating-two-letter-words
2387-partition-array-such-that-maximum-difference-is-k
2395-longest-binary-subsequence-less-than-or-equal-to-k
2497-maximum-matching-of-players-with-trainers
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2689-rearranging-fruits
2704-maximum-difference-by-remapping-a-digit
2720-minimize-the-maximum-difference-of-pairs
3241-divide-array-into-arrays-with-max-difference
3307-find-the-maximum-sum-of-node-values
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3738-make-array-non-decreasing
3741-reschedule-meetings-for-maximum-free-time-ii
3743-reschedule-meetings-for-maximum-free-time-i

Prefix Sum

0238-product-of-array-except-self
0724-find-pivot-index
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1538-maximum-points-you-can-obtain-from-cards
1833-find-the-highest-altitude
2249-count-the-hidden-sequences
2394-count-subarrays-with-score-less-than-k
2529-range-product-queries-of-powers
2915-count-of-interesting-subarrays
3618-find-the-original-typed-string-ii
3761-maximum-difference-between-even-and-odd-frequency-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair

Combinatorics

2415-count-the-number-of-ideal-arrays
3201-distribute-candies-among-children-ii

Number Theory

0258-add-digits
2415-count-the-number-of-ideal-arrays

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0387-first-unique-character-in-a-string
1802-number-of-students-unable-to-eat-lunch
2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds

Monotonic Queue

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

Bit Manipulation

0029-divide-two-integers
0078-subsets
0136-single-number
0231-power-of-two
0342-power-of-four
0934-bitwise-ors-of-subarrays
1839-decode-xored-array
1873-longest-nice-substring
2170-count-number-of-maximum-bitwise-or-subsets
2308-divide-array-into-equal-pairs
2323-minimum-bit-flips-to-convert-number
2498-smallest-subarrays-with-maximum-bitwise-or
2503-longest-subarray-with-maximum-bitwise-and
2529-range-product-queries-of-powers
3307-find-the-maximum-sum-of-node-values
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii

Simulation

0258-add-digits
0412-fizz-buzz
0415-add-strings
0495-teemo-attacking
0682-baseball-game
0735-asteroid-collision
0874-backspace-string-compare
1802-number-of-students-unable-to-eat-lunch
2048-build-array-from-permutation
2260-divide-a-string-into-groups-of-size-k
2479-meeting-rooms-iii
2551-apply-operations-to-an-array
2800-minimum-string-length-after-removing-substrings
3600-find-the-k-th-character-in-string-game-i

Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0775-n-ary-tree-preorder-traversal
0776-n-ary-tree-postorder-traversal
1029-vertical-order-traversal-of-a-binary-tree
3307-find-the-maximum-sum-of-node-values
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Depth-First Search

0094-binary-tree-inorder-traversal
0100-same-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0386-lexicographical-numbers
0775-n-ary-tree-preorder-traversal
0776-n-ary-tree-postorder-traversal
1029-vertical-order-traversal-of-a-binary-tree
1350-remove-sub-folders-from-the-filesystem
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Breadth-First Search

0100-same-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
0945-snakes-and-ladders
1029-vertical-order-traversal-of-a-binary-tree
1424-maximum-candies-you-can-get-from-boxes
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Counting Sort

0274-h-index
0561-array-partition

Matrix

0085-maximal-rectangle
0945-snakes-and-ladders
3459-find-the-minimum-area-to-cover-all-ones-ii
3461-find-the-minimum-area-to-cover-all-ones-i
3648-find-the-maximum-number-of-fruits-collected
3748-sort-matrix-by-diagonals

Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0402-remove-k-digits
0496-next-greater-element-i
0503-next-greater-element-ii
0678-valid-parenthesis-string
0682-baseball-game
0735-asteroid-collision
0739-daily-temperatures
0775-n-ary-tree-preorder-traversal
0776-n-ary-tree-postorder-traversal
0874-backspace-string-compare
0943-sum-of-subarray-minimums
1128-remove-all-adjacent-duplicates-in-string
1666-make-the-string-great
1737-maximum-nesting-depth-of-the-parentheses
1802-number-of-students-unable-to-eat-lunch
2227-sum-of-subarray-ranges
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2800-minimum-string-length-after-removing-substrings
3445-lexicographically-minimum-string-after-removing-stars
3738-make-array-non-decreasing

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0402-remove-k-digits
0496-next-greater-element-i
0503-next-greater-element-ii
0739-daily-temperatures
0943-sum-of-subarray-minimums
2227-sum-of-subarray-ranges
3738-make-array-non-decreasing

Enumeration

0900-reordered-power-of-2
2140-longest-subsequence-repeated-k-times
2170-count-number-of-maximum-bitwise-or-subsets
2202-sum-of-k-mirror-numbers
3201-distribute-candies-among-children-ii
3459-find-the-minimum-area-to-cover-all-ones-ii
3741-reschedule-meetings-for-maximum-free-time-ii
3761-maximum-difference-between-even-and-odd-frequency-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair

Trie

0014-longest-common-prefix
0386-lexicographical-numbers
0440-k-th-smallest-in-lexicographical-order
1350-remove-sub-folders-from-the-filesystem
2079-delete-duplicate-folders-in-system

Graph

1424-maximum-candies-you-can-get-from-boxes

Linked List

0019-remove-nth-node-from-end-of-list
0082-remove-duplicates-from-sorted-list-ii
0083-remove-duplicates-from-sorted-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0160-intersection-of-two-linked-lists
0203-remove-linked-list-elements
0206-reverse-linked-list
0234-palindrome-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

Recursion

0050-powx-n
0203-remove-linked-list-elements
0206-reverse-linked-list
0231-power-of-two
0234-palindrome-linked-list
0326-power-of-three
0342-power-of-four
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii

Union Find

1058-lexicographically-smallest-equivalent-string

Heap (Priority Queue)

1478-maximum-number-of-events-that-can-be-attended
2204-find-subsequence-of-length-k-with-the-largest-sum
2267-minimum-difference-in-sums-after-removal-of-elements
2479-meeting-rooms-iii
3445-lexicographically-minimum-string-after-removing-stars

Backtracking

0078-subsets
2140-longest-subsequence-repeated-k-times
2170-count-number-of-maximum-bitwise-or-subsets

Brainteaser

0292-nim-game
2503-longest-subarray-with-maximum-bitwise-and

Game Theory

0292-nim-game

Interactive

0278-first-bad-version

Design

0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks

Memoization

2028-the-earliest-and-latest-rounds-where-players-compete
2395-longest-binary-subsequence-less-than-or-equal-to-k

Binary Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
1029-vertical-order-traversal-of-a-binary-tree

Hash Function

2079-delete-duplicate-folders-in-system

Probability and Statistics

0826-soup-servings