LeetCode

LeetCode Topics

Array

0001-two-sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0056-merge-intervals
0066-plus-one
0078-subsets
0088-merge-sorted-array
0121-best-time-to-buy-and-sell-stock
0136-single-number
0150-evaluate-reverse-polish-notation
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0200-number-of-islands
0209-minimum-size-subarray-sum
0215-kth-largest-element-in-an-array
0228-summary-ranges
0268-missing-number
0303-range-sum-query-immutable
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0373-find-k-pairs-with-smallest-sums
0417-pacific-atlantic-water-flow
0448-find-all-numbers-disappeared-in-an-array
0463-island-perimeter
0503-next-greater-element-ii
0523-continuous-subarray-sum
0525-contiguous-array
0560-subarray-sum-equals-k
0561-array-partition
0566-reshape-the-matrix
0594-longest-harmonious-subsequence
0605-can-place-flowers
0643-maximum-average-subarray-i
0645-set-mismatch
0661-image-smoother
0695-max-area-of-island
0713-subarray-product-less-than-k
0724-find-pivot-index
0729-my-calendar-i
0733-flood-fill
0735-asteroid-collision
0739-daily-temperatures
0777-toeplitz-matrix
0837-most-common-word
0861-flipping-an-image
0890-lemonade-change
0898-transpose-matrix
0907-koko-eating-bananas
0940-fruit-into-baskets
0950-x-of-a-kind-in-a-deck-of-cards
0971-shortest-bridge
0999-regions-cut-by-slashes
1016-subarray-sums-divisible-by-k
1032-satisfiability-of-equality-equations
1046-max-consecutive-ones-iii
1062-partition-array-into-three-parts-with-equal-sum
1112-find-words-that-can-be-formed-by-characters
1117-as-far-from-land-as-possible
1227-number-of-equivalent-domino-pairs
1308-smallest-string-with-swaps
1325-path-with-maximum-probability
1335-maximum-candies-allocated-to-k-children
1370-count-number-of-nice-subarrays
1458-sort-integers-by-the-number-of-1-bits
1514-minimum-value-to-get-positive-step-by-step-sum
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1582-design-browser-history
1603-running-sum-of-1d-array
1631-number-of-sub-arrays-with-odd-sum
1635-number-of-good-pairs
1663-detect-cycles-in-2d-grid
1675-magnetic-force-between-two-balls
1693-sum-of-all-odd-length-subarrays
1706-min-cost-to-connect-all-points
1762-furthest-building-you-can-reach
1776-minimum-operations-to-reduce-x-to-zero
1786-count-the-number-of-consistent-strings
1833-find-the-highest-altitude
1848-sum-of-unique-elements
1849-maximum-absolute-sum-of-any-subarray
1962-single-threaded-cpu
2038-nearest-exit-from-entrance-in-maze
2116-count-number-of-pairs-with-absolute-difference-k
2163-kth-distinct-string-in-an-array
2190-count-common-words-with-one-occurrence
2206-detonate-the-maximum-bombs
2244-number-of-laser-beams-in-a-bank
2269-count-elements-with-strictly-smaller-and-greater-elements
2308-divide-array-into-equal-pairs
2312-most-frequent-number-following-key-in-an-array
2329-maximum-product-after-k-increments
2331-intersection-of-multiple-arrays
2394-count-subarrays-with-score-less-than-k
2421-maximum-number-of-pairs-in-array
2429-design-a-food-rating-system
2433-best-poker-hand
2445-reachable-nodes-with-restrictions
2594-count-pairs-of-similar-strings
2600-maximum-tastiness-of-candy-basket
2614-maximum-count-of-positive-integer-and-negative-integer
2624-difference-between-element-sum-and-digit-sum-of-an-array
2634-minimum-common-value
2639-separate-the-digits-in-an-array
2654-count-the-number-of-vowel-strings-in-range
2665-minimum-time-to-repair-cars
2690-house-robber-iv
2699-count-the-number-of-fair-pairs
2831-number-of-beautiful-pairs
2876-number-of-employees-who-met-the-target
2881-split-strings-by-separator
2902-max-pair-sum-in-an-array
2915-count-of-interesting-subarrays
2917-count-pairs-whose-sum-is-less-than-target
2977-check-if-a-string-is-an-acronym-of-words
3034-points-that-intersect-with-cars
3044-minimum-operations-to-collect-elements
3045-minimum-right-shifts-to-sort-the-array
3093-sum-of-values-at-indices-with-k-set-bits
3154-maximum-value-of-an-ordered-triplet-i
3220-count-tested-devices-after-test-operations
3242-count-elements-with-maximum-frequency
3324-split-the-array
3421-count-pairs-that-form-a-complete-day-i
3778-transform-array-by-parity

Math

0009-palindrome-number
0013-roman-to-integer
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0150-evaluate-reverse-polish-notation
0168-excel-sheet-column-title
0171-excel-sheet-column-number
0202-happy-number
0227-basic-calculator-ii
0263-ugly-number
0268-missing-number
0292-nim-game
0342-power-of-four
0367-valid-perfect-square
0412-fizz-buzz
0523-continuous-subarray-sum
0728-self-dividing-numbers
0950-x-of-a-kind-in-a-deck-of-cards
1013-fibonacci-number
1370-count-number-of-nice-subarrays
1631-number-of-sub-arrays-with-odd-sum
1635-number-of-good-pairs
1693-sum-of-all-odd-length-subarrays
1844-maximum-number-of-balls-in-a-box
2206-detonate-the-maximum-bombs
2244-number-of-laser-beams-in-a-bank
2624-difference-between-element-sum-and-digit-sum-of-an-array
2630-alternating-digit-sum
2831-number-of-beautiful-pairs
2955-account-balance-after-rounded-purchase
2998-count-symmetric-integers
3055-maximum-odd-binary-number

Hash Table

0001-two-sum
0013-roman-to-integer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0169-majority-element
0202-happy-number
0205-isomorphic-strings
0268-missing-number
0290-word-pattern
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0383-ransom-note
0387-first-unique-character-in-a-string
0389-find-the-difference
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0448-find-all-numbers-disappeared-in-an-array
0523-continuous-subarray-sum
0525-contiguous-array
0560-subarray-sum-equals-k
0594-longest-harmonious-subsequence
0645-set-mismatch
0652-find-duplicate-subtrees
0837-most-common-word
0940-fruit-into-baskets
0950-x-of-a-kind-in-a-deck-of-cards
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
1016-subarray-sums-divisible-by-k
1112-find-words-that-can-be-formed-by-characters
1227-number-of-equivalent-domino-pairs
1297-maximum-number-of-balloons
1308-smallest-string-with-swaps
1370-count-number-of-nice-subarrays
1554-minimum-time-to-collect-all-apples-in-a-tree
1635-number-of-good-pairs
1776-minimum-operations-to-reduce-x-to-zero
1786-count-the-number-of-consistent-strings
1844-maximum-number-of-balls-in-a-box
1848-sum-of-unique-elements
1915-check-if-one-string-swap-can-make-strings-equal
2053-check-if-all-characters-have-equal-number-of-occurrences
2116-count-number-of-pairs-with-absolute-difference-k
2163-kth-distinct-string-in-an-array
2177-check-whether-two-strings-are-almost-equivalent
2190-count-common-words-with-one-occurrence
2308-divide-array-into-equal-pairs
2312-most-frequent-number-following-key-in-an-array
2331-intersection-of-multiple-arrays
2372-rearrange-characters-to-make-target-string
2377-check-if-number-has-equal-digit-count-and-digit-value
2413-smallest-number-in-infinite-set
2421-maximum-number-of-pairs-in-array
2427-first-letter-to-appear-twice
2429-design-a-food-rating-system
2433-best-poker-hand
2445-reachable-nodes-with-restrictions
2532-remove-letter-to-equalize-frequency
2594-count-pairs-of-similar-strings
2634-minimum-common-value
2831-number-of-beautiful-pairs
2902-max-pair-sum-in-an-array
2915-count-of-interesting-subarrays
3034-points-that-intersect-with-cars
3044-minimum-operations-to-collect-elements
3242-count-elements-with-maximum-frequency
3324-split-the-array
3349-maximum-length-substring-with-two-occurrences
3421-count-pairs-that-form-a-complete-day-i
3736-find-valid-pair-of-adjacent-digits-in-string
3753-maximum-difference-between-even-and-odd-frequency-i
3871-minimum-deletions-for-at-most-k-distinct-characters
3872-find-most-frequent-vowel-and-consonant

Two Pointers

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
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0160-intersection-of-two-linked-lists
0167-two-sum-ii-input-array-is-sorted
0202-happy-number
0234-palindrome-linked-list
0344-reverse-string
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0392-is-subsequence
0680-valid-palindrome-ii
0861-flipping-an-image
0908-middle-of-the-linked-list
2634-minimum-common-value
2699-count-the-number-of-fair-pairs
2917-count-pairs-whose-sum-is-less-than-target

Binary Search

0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0069-sqrtx
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0268-missing-number
0278-first-bad-version
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0367-valid-perfect-square
0713-subarray-product-less-than-k
0729-my-calendar-i
0907-koko-eating-bananas
1046-max-consecutive-ones-iii
1321-get-equal-substrings-within-budget
1335-maximum-candies-allocated-to-k-children
1675-magnetic-force-between-two-balls
1776-minimum-operations-to-reduce-x-to-zero
2394-count-subarrays-with-score-less-than-k
2600-maximum-tastiness-of-candy-basket
2614-maximum-count-of-positive-integer-and-negative-integer
2634-minimum-common-value
2665-minimum-time-to-repair-cars
2690-house-robber-iv
2699-count-the-number-of-fair-pairs
2917-count-pairs-whose-sum-is-less-than-target

Simulation

0067-add-binary
0412-fizz-buzz
0566-reshape-the-matrix
0735-asteroid-collision
0861-flipping-an-image
0898-transpose-matrix
1708-design-parking-system
2639-separate-the-digits-in-an-array
2886-faulty-keyboard
3220-count-tested-devices-after-test-operations

String

0013-roman-to-integer
0014-longest-common-prefix
0020-valid-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0058-length-of-last-word
0067-add-binary
0071-simplify-path
0125-valid-palindrome
0168-excel-sheet-column-title
0171-excel-sheet-column-number
0205-isomorphic-strings
0227-basic-calculator-ii
0290-word-pattern
0344-reverse-string
0383-ransom-note
0387-first-unique-character-in-a-string
0389-find-the-difference
0392-is-subsequence
0412-fizz-buzz
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0680-valid-palindrome-ii
0837-most-common-word
0957-minimum-add-to-make-parentheses-valid
1032-satisfiability-of-equality-equations
1112-find-words-that-can-be-formed-by-characters
1297-maximum-number-of-balloons
1304-longest-happy-string
1308-smallest-string-with-swaps
1320-remove-all-adjacent-duplicates-in-string-ii
1321-get-equal-substrings-within-budget
1341-split-a-string-in-balanced-strings
1537-maximum-score-after-splitting-a-string
1786-count-the-number-of-consistent-strings
1823-determine-if-string-halves-are-alike
1915-check-if-one-string-swap-can-make-strings-equal
2053-check-if-all-characters-have-equal-number-of-occurrences
2163-kth-distinct-string-in-an-array
2177-check-whether-two-strings-are-almost-equivalent
2190-count-common-words-with-one-occurrence
2244-number-of-laser-beams-in-a-bank
2372-rearrange-characters-to-make-target-string
2377-check-if-number-has-equal-digit-count-and-digit-value
2427-first-letter-to-appear-twice
2429-design-a-food-rating-system
2532-remove-letter-to-equalize-frequency
2594-count-pairs-of-similar-strings
2654-count-the-number-of-vowel-strings-in-range
2881-split-strings-by-separator
2886-faulty-keyboard
2977-check-if-a-string-is-an-acronym-of-words
3019-furthest-point-from-origin
3055-maximum-odd-binary-number
3349-maximum-length-substring-with-two-occurrences
3736-find-valid-pair-of-adjacent-digits-in-string
3753-maximum-difference-between-even-and-odd-frequency-i
3871-minimum-deletions-for-at-most-k-distinct-characters
3872-find-most-frequent-vowel-and-consonant

Sorting

0056-merge-intervals
0088-merge-sorted-array
0169-majority-element
0215-kth-largest-element-in-an-array
0268-missing-number
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0389-find-the-difference
0561-array-partition
0594-longest-harmonious-subsequence
0645-set-mismatch
1308-smallest-string-with-swaps
1458-sort-integers-by-the-number-of-1-bits
1675-magnetic-force-between-two-balls
1962-single-threaded-cpu
2269-count-elements-with-strictly-smaller-and-greater-elements
2331-intersection-of-multiple-arrays
2600-maximum-tastiness-of-candy-basket
2699-count-the-number-of-fair-pairs
2917-count-pairs-whose-sum-is-less-than-target
3778-transform-array-by-parity
3871-minimum-deletions-for-at-most-k-distinct-characters

Counting

0169-majority-element
0347-top-k-frequent-elements
0383-ransom-note
0387-first-unique-character-in-a-string
0594-longest-harmonious-subsequence
0837-most-common-word
0950-x-of-a-kind-in-a-deck-of-cards
1112-find-words-that-can-be-formed-by-characters
1227-number-of-equivalent-domino-pairs
1297-maximum-number-of-balloons
1341-split-a-string-in-balanced-strings
1458-sort-integers-by-the-number-of-1-bits
1635-number-of-good-pairs
1708-design-parking-system
1786-count-the-number-of-consistent-strings
1823-determine-if-string-halves-are-alike
1844-maximum-number-of-balls-in-a-box
1848-sum-of-unique-elements
1915-check-if-one-string-swap-can-make-strings-equal
2053-check-if-all-characters-have-equal-number-of-occurrences
2116-count-number-of-pairs-with-absolute-difference-k
2163-kth-distinct-string-in-an-array
2177-check-whether-two-strings-are-almost-equivalent
2190-count-common-words-with-one-occurrence
2269-count-elements-with-strictly-smaller-and-greater-elements
2308-divide-array-into-equal-pairs
2312-most-frequent-number-following-key-in-an-array
2331-intersection-of-multiple-arrays
2372-rearrange-characters-to-make-target-string
2377-check-if-number-has-equal-digit-count-and-digit-value
2421-maximum-number-of-pairs-in-array
2427-first-letter-to-appear-twice
2433-best-poker-hand
2532-remove-letter-to-equalize-frequency
2594-count-pairs-of-similar-strings
2614-maximum-count-of-positive-integer-and-negative-integer
2654-count-the-number-of-vowel-strings-in-range
2831-number-of-beautiful-pairs
3019-furthest-point-from-origin
3220-count-tested-devices-after-test-operations
3242-count-elements-with-maximum-frequency
3324-split-the-array
3421-count-pairs-that-form-a-complete-day-i
3736-find-valid-pair-of-adjacent-digits-in-string
3753-maximum-difference-between-even-and-odd-frequency-i
3778-transform-array-by-parity
3871-minimum-deletions-for-at-most-k-distinct-characters
3872-find-most-frequent-vowel-and-consonant

Greedy

0561-array-partition
0605-can-place-flowers
0680-valid-palindrome-ii
0890-lemonade-change
0957-minimum-add-to-make-parentheses-valid
1062-partition-array-into-three-parts-with-equal-sum
1304-longest-happy-string
1341-split-a-string-in-balanced-strings
1762-furthest-building-you-can-reach
2329-maximum-product-after-k-increments
2600-maximum-tastiness-of-candy-basket
2690-house-robber-iv
3055-maximum-odd-binary-number
3871-minimum-deletions-for-at-most-k-distinct-characters

Enumeration

2998-count-symmetric-integers

Prefix Sum

0209-minimum-size-subarray-sum
0303-range-sum-query-immutable
0523-continuous-subarray-sum
0525-contiguous-array
0560-subarray-sum-equals-k
0713-subarray-product-less-than-k
0724-find-pivot-index
1016-subarray-sums-divisible-by-k
1046-max-consecutive-ones-iii
1321-get-equal-substrings-within-budget
1370-count-number-of-nice-subarrays
1514-minimum-value-to-get-positive-step-by-step-sum
1537-maximum-score-after-splitting-a-string
1603-running-sum-of-1d-array
1631-number-of-sub-arrays-with-odd-sum
1693-sum-of-all-odd-length-subarrays
1776-minimum-operations-to-reduce-x-to-zero
1833-find-the-highest-altitude
2394-count-subarrays-with-score-less-than-k
2915-count-of-interesting-subarrays
3034-points-that-intersect-with-cars

Bit Manipulation

0067-add-binary
0078-subsets
0136-single-number
0190-reverse-bits
0191-number-of-1-bits
0268-missing-number
0342-power-of-four
0389-find-the-difference
0645-set-mismatch
0861-flipping-an-image
1458-sort-integers-by-the-number-of-1-bits
1786-count-the-number-of-consistent-strings
2308-divide-array-into-equal-pairs
2427-first-letter-to-appear-twice
2594-count-pairs-of-similar-strings
3044-minimum-operations-to-collect-elements
3093-sum-of-values-at-indices-with-k-set-bits

Backtracking

0078-subsets
0113-path-sum-ii

Divide and Conquer

0169-majority-element
0190-reverse-bits
0191-number-of-1-bits
0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements

Linked List

0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0083-remove-duplicates-from-sorted-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0234-palindrome-linked-list
0328-odd-even-linked-list
0908-middle-of-the-linked-list
1582-design-browser-history

Recursion

0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0143-reorder-list
0206-reverse-linked-list
0234-palindrome-linked-list
0342-power-of-four
1013-fibonacci-number

Stack

0020-valid-parentheses
0071-simplify-path
0143-reorder-list
0150-evaluate-reverse-polish-notation
0227-basic-calculator-ii
0234-palindrome-linked-list
0503-next-greater-element-ii
0735-asteroid-collision
0739-daily-temperatures
0957-minimum-add-to-make-parentheses-valid
1320-remove-all-adjacent-duplicates-in-string-ii
1582-design-browser-history

Design

0303-range-sum-query-immutable
0729-my-calendar-i
1582-design-browser-history
1708-design-parking-system
2413-smallest-number-in-infinite-set
2429-design-a-food-rating-system

Sliding Window

0209-minimum-size-subarray-sum
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0594-longest-harmonious-subsequence
0643-maximum-average-subarray-i
0713-subarray-product-less-than-k
0940-fruit-into-baskets
1046-max-consecutive-ones-iii
1321-get-equal-substrings-within-budget
1370-count-number-of-nice-subarrays
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1776-minimum-operations-to-reduce-x-to-zero
2394-count-subarrays-with-score-less-than-k
3349-maximum-length-substring-with-two-occurrences

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
0373-find-k-pairs-with-smallest-sums
0744-network-delay-time
0803-cheapest-flights-within-k-stops
1304-longest-happy-string
1325-path-with-maximum-probability
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1762-furthest-building-you-can-reach
1962-single-threaded-cpu
2329-maximum-product-after-k-increments
2413-smallest-number-in-infinite-set
2429-design-a-food-rating-system

Quickselect

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

Bucket Sort

0347-top-k-frequent-elements

Doubly-Linked List

1582-design-browser-history

Data Stream

1582-design-browser-history

Segment Tree

0729-my-calendar-i

Ordered Set

0729-my-calendar-i
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
2413-smallest-number-in-infinite-set
2429-design-a-food-rating-system

Monotonic Stack

0503-next-greater-element-ii
0739-daily-temperatures

Trie

0014-longest-common-prefix

String Matching

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

Dynamic Programming

0070-climbing-stairs
0121-best-time-to-buy-and-sell-stock
0392-is-subsequence
0803-cheapest-flights-within-k-stops
1013-fibonacci-number
1117-as-far-from-land-as-possible
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1631-number-of-sub-arrays-with-odd-sum
1849-maximum-absolute-sum-of-any-subarray
2690-house-robber-iv

Memoization

0070-climbing-stairs
1013-fibonacci-number

Number Theory

0950-x-of-a-kind-in-a-deck-of-cards
2831-number-of-beautiful-pairs

Queue

0387-first-unique-character-in-a-string
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Counting Sort

0561-array-partition

Interactive

0278-first-bad-version

Brainteaser

0292-nim-game

Game Theory

0292-nim-game

Matrix

0200-number-of-islands
0417-pacific-atlantic-water-flow
0463-island-perimeter
0566-reshape-the-matrix
0661-image-smoother
0695-max-area-of-island
0733-flood-fill
0777-toeplitz-matrix
0861-flipping-an-image
0898-transpose-matrix
0971-shortest-bridge
0999-regions-cut-by-slashes
1117-as-far-from-land-as-possible
1663-detect-cycles-in-2d-grid
2038-nearest-exit-from-entrance-in-maze
2244-number-of-laser-beams-in-a-bank

Depth-First Search

0112-path-sum
0113-path-sum-ii
0129-sum-root-to-leaf-numbers
0200-number-of-islands
0236-lowest-common-ancestor-of-a-binary-tree
0417-pacific-atlantic-water-flow
0463-island-perimeter
0547-number-of-provinces
0652-find-duplicate-subtrees
0684-redundant-connection
0695-max-area-of-island
0733-flood-fill
0744-network-delay-time
0803-cheapest-flights-within-k-stops
0820-find-eventual-safe-states
0871-keys-and-rooms
0922-possible-bipartition
0971-shortest-bridge
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
1308-smallest-string-with-swaps
1442-number-of-operations-to-make-network-connected
1492-time-needed-to-inform-all-employees
1554-minimum-time-to-collect-all-apples-in-a-tree
1663-detect-cycles-in-2d-grid
2121-find-if-path-exists-in-graph
2206-detonate-the-maximum-bombs
2445-reachable-nodes-with-restrictions

Breadth-First Search

0112-path-sum
0200-number-of-islands
0417-pacific-atlantic-water-flow
0463-island-perimeter
0547-number-of-provinces
0684-redundant-connection
0695-max-area-of-island
0733-flood-fill
0744-network-delay-time
0803-cheapest-flights-within-k-stops
0820-find-eventual-safe-states
0871-keys-and-rooms
0922-possible-bipartition
0971-shortest-bridge
0999-regions-cut-by-slashes
1117-as-far-from-land-as-possible
1308-smallest-string-with-swaps
1442-number-of-operations-to-make-network-connected
1492-time-needed-to-inform-all-employees
1554-minimum-time-to-collect-all-apples-in-a-tree
1663-detect-cycles-in-2d-grid
2038-nearest-exit-from-entrance-in-maze
2121-find-if-path-exists-in-graph
2206-detonate-the-maximum-bombs
2445-reachable-nodes-with-restrictions

Monotonic Queue

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

Union Find

0200-number-of-islands
0547-number-of-provinces
0684-redundant-connection
0695-max-area-of-island
0922-possible-bipartition
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
1032-satisfiability-of-equality-equations
1308-smallest-string-with-swaps
1442-number-of-operations-to-make-network-connected
1663-detect-cycles-in-2d-grid
1706-min-cost-to-connect-all-points
2121-find-if-path-exists-in-graph
2445-reachable-nodes-with-restrictions

Graph

0547-number-of-provinces
0684-redundant-connection
0744-network-delay-time
0803-cheapest-flights-within-k-stops
0820-find-eventual-safe-states
0871-keys-and-rooms
0922-possible-bipartition
0984-most-stones-removed-with-same-row-or-column
1032-satisfiability-of-equality-equations
1325-path-with-maximum-probability
1442-number-of-operations-to-make-network-connected
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1706-min-cost-to-connect-all-points
2121-find-if-path-exists-in-graph
2206-detonate-the-maximum-bombs
2445-reachable-nodes-with-restrictions

Tree

0112-path-sum
0113-path-sum-ii
0129-sum-root-to-leaf-numbers
0236-lowest-common-ancestor-of-a-binary-tree
0652-find-duplicate-subtrees
1492-time-needed-to-inform-all-employees
1554-minimum-time-to-collect-all-apples-in-a-tree
2445-reachable-nodes-with-restrictions

Geometry

2206-detonate-the-maximum-bombs

Binary Tree

0112-path-sum
0113-path-sum-ii
0129-sum-root-to-leaf-numbers
0236-lowest-common-ancestor-of-a-binary-tree
0652-find-duplicate-subtrees

Shortest Path

0744-network-delay-time
0803-cheapest-flights-within-k-stops
1325-path-with-maximum-probability
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance

Topological Sort

0820-find-eventual-safe-states

Minimum Spanning Tree

1706-min-cost-to-connect-all-points