Leetcode

Leetcode + interviewBit + Scaler + Codechef

LeetCode Topics

Array

0011-container-with-most-water
0036-valid-sudoku
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0051-n-queens
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0075-sort-colors
0090-subsets-ii
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0120-triangle
0135-candy
0162-find-peak-element
0198-house-robber
0417-pacific-atlantic-water-flow
0594-longest-harmonious-subsequence
0679-24-game
0717-1-bit-and-2-bit-characters
0747-min-cost-climbing-stairs
0797-rabbits-in-forest
0934-bitwise-ors-of-subarrays
0940-fruit-into-baskets
0945-snakes-and-ladders
1018-largest-perimeter-triangle
1018-binary-prefix-divisible-by-5
1049-minimum-domino-rotations-for-equal-row
1073-number-of-enclaves
1111-minimum-score-triangulation-of-polygon
1227-number-of-equivalent-domino-pairs
1262-greatest-sum-divisible-by-three
1266-minimum-time-visiting-all-points
1293-three-consecutive-odds
1350-remove-sub-folders-from-the-filesystem
1351-count-negative-numbers-in-a-sorted-matrix
1380-number-of-closed-islands
1390-four-divisors
1402-count-square-submatrices-with-all-ones
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
1510-find-lucky-integer-in-an-array
1586-longest-subarray-of-1s-after-deleting-one-element
1590-make-sum-divisible-by-p
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1628-count-submatrices-with-all-ones
1813-maximum-erasure-value
1851-maximum-number-of-events-that-can-be-attended-ii
1895-largest-magic-square
1993-sum-of-all-subset-xor-totals
1995-finding-pairs-with-a-certain-sum
2048-build-array-from-permutation
2137-final-value-of-variable-after-performing-operations
2141-maximum-running-time-of-n-computers
2144-maximum-difference-between-increasing-elements
2150-kth-smallest-product-of-two-sorted-arrays
2180-maximum-number-of-tasks-you-can-assign
2204-find-subsequence-of-length-k-with-the-largest-sum
2215-finding-3-digit-even-numbers
2229-maximum-fruits-harvested-after-at-most-k-steps
2237-longest-palindrome-by-concatenating-two-letter-words
2249-count-the-hidden-sequences
2267-minimum-difference-in-sums-after-removal-of-elements
2280-count-good-triplets-in-an-array
2316-count-hills-and-valleys-in-an-array
2387-partition-array-such-that-maximum-difference-is-k
2392-successful-pairs-of-spells-and-potions
2394-count-subarrays-with-score-less-than-k
2400-minimum-score-after-removals-on-a-tree
2432-number-of-zero-filled-subarrays
2435-paths-in-matrix-whose-sum-is-divisible-by-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
2530-minimize-maximum-of-array
2624-difference-between-element-sum-and-digit-sum-of-an-array
2625-increment-submatrices-by-one
2626-count-the-number-of-good-subarrays
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
2975-maximum-square-area-by-removing-fences-from-a-field
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3154-maximum-value-of-an-ordered-triplet-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3190-find-minimum-operations-to-make-all-elements-divisible-by-three
3194-find-words-containing-character
3213-count-subarrays-where-max-element-appears-at-least-k-times
3241-divide-array-into-arrays-with-max-difference
3242-count-elements-with-maximum-frequency
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3381-maximum-subarray-sum-with-length-divisible-by-k
3432-count-partitions-with-even-sum-difference
3453-separate-squares-i
3454-separate-squares-ii
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
3512-minimum-operations-to-make-array-sum-divisible-by-k
3583-count-special-triplets
3625-count-number-of-trapezoids-ii
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3639-zero-array-transformation-i
3647-zero-array-transformation-iii
3648-find-the-maximum-number-of-fruits-collected
3685-count-subarrays-of-length-three-with-a-condition
3733-length-of-longest-v-shaped-diagonal-segment
3741-reschedule-meetings-for-maximum-free-time-ii
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3748-sort-matrix-by-diagonals
3788-maximum-unique-subarray-sum-after-deletion
3789-maximize-subarrays-after-removing-one-conflicting-pair
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii
3797-design-spreadsheet
3827-implement-router

Dynamic Programming

0062-unique-paths
0063-unique-paths-ii
0064-minimum-path-sum
0072-edit-distance
0120-triangle
0124-binary-tree-maximum-path-sum
0131-palindrome-partitioning
0198-house-robber
0337-house-robber-iii
0712-minimum-ascii-delete-sum-for-two-strings
0747-min-cost-climbing-stairs
0806-domino-and-tromino-tiling
0826-soup-servings
0867-new-21-game
0868-push-dominoes
0934-bitwise-ors-of-subarrays
1111-minimum-score-triangulation-of-polygon
1250-longest-common-subsequence
1262-greatest-sum-divisible-by-three
1402-count-square-submatrices-with-all-ones
1586-longest-subarray-of-1s-after-deleting-one-element
1628-count-submatrices-with-all-ones
1851-maximum-number-of-events-that-can-be-attended-ii
1986-largest-color-value-in-a-directed-graph
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
2408-number-of-people-aware-of-a-secret
2415-count-the-number-of-ideal-arrays
2435-paths-in-matrix-whose-sum-is-divisible-by-k
2530-minimize-maximum-of-array
2882-ways-to-express-an-integer-as-sum-of-powers
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
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
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations
3648-find-the-maximum-number-of-fruits-collected
3733-length-of-longest-v-shaped-diagonal-segment

Two Pointers

0011-container-with-most-water
0075-sort-colors
0143-reorder-list
0165-compare-version-numbers
0234-palindrome-linked-list
0868-push-dominoes
0908-middle-of-the-linked-list
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2392-successful-pairs-of-spells-and-potions
2497-maximum-matching-of-players-with-trainers
2699-count-the-number-of-fair-pairs
3683-find-the-lexicographically-largest-string-from-the-box-i

Binary Search

0162-find-peak-element
1351-count-negative-numbers-in-a-sorted-matrix
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1851-maximum-number-of-events-that-can-be-attended-ii
2141-maximum-running-time-of-n-computers
2150-kth-smallest-product-of-two-sorted-arrays
2180-maximum-number-of-tasks-you-can-assign
2229-maximum-fruits-harvested-after-at-most-k-steps
2280-count-good-triplets-in-an-array
2392-successful-pairs-of-spells-and-potions
2394-count-subarrays-with-score-less-than-k
2498-smallest-subarrays-with-maximum-bitwise-or
2530-minimize-maximum-of-array
2699-count-the-number-of-fair-pairs
2720-minimize-the-maximum-difference-of-pairs
3453-separate-squares-i
3454-separate-squares-ii
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii
3827-implement-router

Sorting

0075-sort-colors
0594-longest-harmonious-subsequence
0900-reordered-power-of-2
1018-largest-perimeter-triangle
1029-vertical-order-traversal-of-a-binary-tree
1262-greatest-sum-divisible-by-three
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
2141-maximum-running-time-of-n-computers
2180-maximum-number-of-tasks-you-can-assign
2204-find-subsequence-of-length-k-with-the-largest-sum
2215-finding-3-digit-even-numbers
2387-partition-array-such-that-maximum-difference-is-k
2392-successful-pairs-of-spells-and-potions
2479-meeting-rooms-iii
2497-maximum-matching-of-players-with-trainers
2699-count-the-number-of-fair-pairs
3241-divide-array-into-arrays-with-max-difference
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3360-minimum-deletions-to-make-string-k-special
3647-zero-array-transformation-iii
3748-sort-matrix-by-diagonals

Hash Table

0036-valid-sudoku
0037-sudoku-solver
0073-set-matrix-zeroes
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0166-fraction-to-recurring-decimal
0208-implement-trie-prefix-tree
0594-longest-harmonious-subsequence
0797-rabbits-in-forest
0865-smallest-subtree-with-all-the-deepest-nodes
0900-reordered-power-of-2
0940-fruit-into-baskets
1015-smallest-integer-divisible-by-k
1029-vertical-order-traversal-of-a-binary-tree
1227-number-of-equivalent-domino-pairs
1500-count-largest-group
1510-find-lucky-integer-in-an-array
1590-make-sum-divisible-by-p
1813-maximum-erasure-value
1986-largest-color-value-in-a-directed-graph
1995-finding-pairs-with-a-certain-sum
2204-find-subsequence-of-length-k-with-the-largest-sum
2215-finding-3-digit-even-numbers
2237-longest-palindrome-by-concatenating-two-letter-words
2479-meeting-rooms-iii
2487-optimal-partition-of-string
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2626-count-the-number-of-good-subarrays
2856-count-complete-subarrays-in-an-array
2915-count-of-interesting-subarrays
2975-maximum-square-area-by-removing-fences-from-a-field
3242-count-elements-with-maximum-frequency
3360-minimum-deletions-to-make-string-k-special
3381-maximum-subarray-sum-with-length-divisible-by-k
3445-lexicographically-minimum-string-after-removing-stars
3583-count-special-triplets
3625-count-number-of-trapezoids-ii
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3678-design-task-manager
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes
3788-maximum-unique-subarray-sum-after-deletion
3797-design-spreadsheet
3827-implement-router
3872-find-most-frequent-vowel-and-consonant

Sliding Window

0594-longest-harmonious-subsequence
0867-new-21-game
0940-fruit-into-baskets
1586-longest-subarray-of-1s-after-deleting-one-element
1813-maximum-erasure-value
2229-maximum-fruits-harvested-after-at-most-k-steps
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
3479-count-the-number-of-substrings-with-dominant-ones
3761-maximum-difference-between-even-and-odd-frequency-ii

Divide and Conquer

0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
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
3454-separate-squares-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Merge Sort

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

Ordered Set

2280-count-good-triplets-in-an-array
3678-design-task-manager
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii
3827-implement-router

Math

0060-permutation-sequence
0062-unique-paths
0166-fraction-to-recurring-decimal
0231-power-of-two
0326-power-of-three
0342-power-of-four
0679-24-game
0797-rabbits-in-forest
0826-soup-servings
0867-new-21-game
0900-reordered-power-of-2
1015-smallest-integer-divisible-by-k
1018-largest-perimeter-triangle
1266-minimum-time-visiting-all-points
1390-four-divisors
1411-convert-binary-number-in-a-linked-list-to-integer
1421-find-numbers-with-even-number-of-digits
1440-convert-integer-to-the-sum-of-two-no-zero-integers
1500-count-largest-group
1523-count-odd-numbers-in-an-interval-range
1529-max-difference-you-can-get-from-changing-an-integer
1636-number-of-substrings-with-only-1s
1642-water-bottles
1925-count-square-sum-triples
1993-sum-of-all-subset-xor-totals
2202-sum-of-k-mirror-numbers
2288-count-operations-to-obtain-zero
2415-count-the-number-of-ideal-arrays
2432-number-of-zero-filled-subarrays
2624-difference-between-element-sum-and-digit-sum-of-an-array
2704-maximum-difference-by-remapping-a-digit
3172-divisible-and-non-divisible-sums-difference
3190-find-minimum-operations-to-make-all-elements-divisible-by-three
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3321-type-of-triangle
3336-water-bottles-ii
3432-count-partitions-with-even-sum-difference
3512-minimum-operations-to-make-array-sum-divisible-by-k
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii
3625-count-number-of-trapezoids-ii
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements
3754-maximum-manhattan-distance-after-k-changes
3830-find-closest-person

Backtracking

0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0051-n-queens
0090-subsets-ii
0131-palindrome-partitioning
0679-24-game
1993-sum-of-all-subset-xor-totals

Bit Manipulation

0090-subsets-ii
0231-power-of-two
0342-power-of-four
0934-bitwise-ors-of-subarrays
1018-binary-prefix-divisible-by-5
1993-sum-of-all-subset-xor-totals
2400-minimum-score-after-removals-on-a-tree
2498-smallest-subarrays-with-maximum-bitwise-or
2503-longest-subarray-with-maximum-bitwise-and
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

Combinatorics

0062-unique-paths
1993-sum-of-all-subset-xor-totals
2415-count-the-number-of-ideal-arrays
3637-count-number-of-balanced-permutations
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements

Enumeration

0900-reordered-power-of-2
1925-count-square-sum-triples
1993-sum-of-all-subset-xor-totals
2202-sum-of-k-mirror-numbers
2215-finding-3-digit-even-numbers
2975-maximum-square-area-by-removing-fences-from-a-field
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3459-find-the-minimum-area-to-cover-all-ones-ii
3479-count-the-number-of-substrings-with-dominant-ones
3683-find-the-lexicographically-largest-string-from-the-box-i
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

String

0072-edit-distance
0131-palindrome-partitioning
0165-compare-version-numbers
0166-fraction-to-recurring-decimal
0208-implement-trie-prefix-tree
0297-serialize-and-deserialize-binary-tree
0712-minimum-ascii-delete-sum-for-two-strings
0868-push-dominoes
1058-lexicographically-smallest-equivalent-string
1250-longest-common-subsequence
1302-delete-characters-to-make-fancy-string
1350-remove-sub-folders-from-the-filesystem
1636-number-of-substrings-with-only-1s
1818-maximum-score-from-removing-substrings
2137-final-value-of-variable-after-performing-operations
2211-count-collisions-on-a-road
2237-longest-palindrome-by-concatenating-two-letter-words
2260-divide-a-string-into-groups-of-size-k
2346-largest-3-same-digit-number-in-string
2395-longest-binary-subsequence-less-than-or-equal-to-k
2470-removing-stars-from-a-string
2487-optimal-partition-of-string
2520-using-a-robot-to-print-the-lexicographically-smallest-string
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3194-find-words-containing-character
3360-minimum-deletions-to-make-string-k-special
3396-valid-word
3445-lexicographically-minimum-string-after-removing-stars
3479-count-the-number-of-substrings-with-dominant-ones
3617-find-the-original-typed-string-i
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations
3683-find-the-lexicographically-largest-string-from-the-box-i
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
3797-design-spreadsheet
3872-find-most-frequent-vowel-and-consonant

Greedy

0011-container-with-most-water
0135-candy
0797-rabbits-in-forest
1018-largest-perimeter-triangle
1049-minimum-domino-rotations-for-equal-row
1262-greatest-sum-divisible-by-three
1478-maximum-number-of-events-that-can-be-attended
1529-max-difference-you-can-get-from-changing-an-integer
1818-maximum-score-from-removing-substrings
2141-maximum-running-time-of-n-computers
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
2487-optimal-partition-of-string
2497-maximum-matching-of-players-with-trainers
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2530-minimize-maximum-of-array
2704-maximum-difference-by-remapping-a-digit
2720-minimize-the-maximum-difference-of-pairs
3143-longest-unequal-adjacent-groups-subsequence-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
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
3647-zero-array-transformation-iii
3741-reschedule-meetings-for-maximum-free-time-ii
3788-maximum-unique-subarray-sum-after-deletion

Prefix Sum

1590-make-sum-divisible-by-p
1895-largest-magic-square
2229-maximum-fruits-harvested-after-at-most-k-steps
2249-count-the-hidden-sequences
2394-count-subarrays-with-score-less-than-k
2530-minimize-maximum-of-array
2625-increment-submatrices-by-one
2915-count-of-interesting-subarrays
3381-maximum-subarray-sum-with-length-divisible-by-k
3432-count-partitions-with-even-sum-difference
3639-zero-array-transformation-i
3647-zero-array-transformation-iii
3761-maximum-difference-between-even-and-odd-frequency-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair

Number Theory

2415-count-the-number-of-ideal-arrays

Matrix

0036-valid-sudoku
0037-sudoku-solver
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0417-pacific-atlantic-water-flow
0945-snakes-and-ladders
1073-number-of-enclaves
1351-count-negative-numbers-in-a-sorted-matrix
1380-number-of-closed-islands
1402-count-square-submatrices-with-all-ones
1628-count-submatrices-with-all-ones
1895-largest-magic-square
2435-paths-in-matrix-whose-sum-is-divisible-by-k
2625-increment-submatrices-by-one
3459-find-the-minimum-area-to-cover-all-ones-ii
3461-find-the-minimum-area-to-cover-all-ones-i
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3648-find-the-maximum-number-of-fruits-collected
3733-length-of-longest-v-shaped-diagonal-segment
3748-sort-matrix-by-diagonals
3797-design-spreadsheet

Queue

2180-maximum-number-of-tasks-you-can-assign
2408-number-of-people-aware-of-a-secret
2527-count-subarrays-with-fixed-bounds
3827-implement-router

Monotonic Queue

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

Stack

0094-binary-tree-inorder-traversal
0143-reorder-list
0144-binary-tree-preorder-traversal
0234-palindrome-linked-list
1628-count-submatrices-with-all-ones
1818-maximum-score-from-removing-substrings
2211-count-collisions-on-a-road
2470-removing-stars-from-a-string
2520-using-a-robot-to-print-the-lexicographically-smallest-string
3445-lexicographically-minimum-string-after-removing-stars

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
0108-convert-sorted-array-to-binary-search-tree
0110-balanced-binary-tree
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0199-binary-tree-right-side-view
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
0337-house-robber-iii
0543-diameter-of-binary-tree
0617-merge-two-binary-trees
0700-search-in-a-binary-search-tree
0783-search-in-a-binary-search-tree
0865-smallest-subtree-with-all-the-deepest-nodes
0998-check-completeness-of-a-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1339-maximum-product-of-splitted-binary-tree
1448-count-good-nodes-in-binary-tree
2400-minimum-score-after-removals-on-a-tree
2872-maximum-number-of-k-divisible-components
3307-find-the-maximum-sum-of-node-values
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

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
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0199-binary-tree-right-side-view
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
0337-house-robber-iii
0386-lexicographical-numbers
0417-pacific-atlantic-water-flow
0543-diameter-of-binary-tree
0617-merge-two-binary-trees
0865-smallest-subtree-with-all-the-deepest-nodes
1029-vertical-order-traversal-of-a-binary-tree
1073-number-of-enclaves
1339-maximum-product-of-splitted-binary-tree
1350-remove-sub-folders-from-the-filesystem
1380-number-of-closed-islands
1448-count-good-nodes-in-binary-tree
2400-minimum-score-after-removals-on-a-tree
2438-find-closest-node-to-given-two-nodes
2582-minimum-score-of-a-path-between-two-cities
2872-maximum-number-of-k-divisible-components
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

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
0108-convert-sorted-array-to-binary-search-tree
0110-balanced-binary-tree
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0199-binary-tree-right-side-view
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
0337-house-robber-iii
0543-diameter-of-binary-tree
0617-merge-two-binary-trees
0700-search-in-a-binary-search-tree
0783-search-in-a-binary-search-tree
0865-smallest-subtree-with-all-the-deepest-nodes
0998-check-completeness-of-a-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1339-maximum-product-of-splitted-binary-tree
1448-count-good-nodes-in-binary-tree

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
0297-serialize-and-deserialize-binary-tree
0417-pacific-atlantic-water-flow
0617-merge-two-binary-trees
0865-smallest-subtree-with-all-the-deepest-nodes
0945-snakes-and-ladders
0998-check-completeness-of-a-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1073-number-of-enclaves
1380-number-of-closed-islands
1424-maximum-candies-you-can-get-from-boxes
1448-count-good-nodes-in-binary-tree
2582-minimum-score-of-a-path-between-two-cities
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Counting

0594-longest-harmonious-subsequence
0900-reordered-power-of-2
1227-number-of-equivalent-domino-pairs
1510-find-lucky-integer-in-an-array
1986-largest-color-value-in-a-directed-graph
2237-longest-palindrome-by-concatenating-two-letter-words
3242-count-elements-with-maximum-frequency
3360-minimum-deletions-to-make-string-k-special
3583-count-special-triplets
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes
3872-find-most-frequent-vowel-and-consonant

Simulation

1642-water-bottles
2048-build-array-from-permutation
2137-final-value-of-variable-after-performing-operations
2211-count-collisions-on-a-road
2260-divide-a-string-into-groups-of-size-k
2288-count-operations-to-obtain-zero
2408-number-of-people-aware-of-a-secret
2470-removing-stars-from-a-string
2479-meeting-rooms-iii
3336-water-bottles-ii
3600-find-the-k-th-character-in-string-game-i
3790-fruits-into-baskets-ii

Graph

1424-maximum-candies-you-can-get-from-boxes
1986-largest-color-value-in-a-directed-graph
2438-find-closest-node-to-given-two-nodes
2582-minimum-score-of-a-path-between-two-cities
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

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
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3647-zero-array-transformation-iii
3678-design-task-manager

Shortest Path

3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Binary Search Tree

0098-validate-binary-search-tree
0108-convert-sorted-array-to-binary-search-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0700-search-in-a-binary-search-tree
0783-search-in-a-binary-search-tree

Topological Sort

1986-largest-color-value-in-a-directed-graph

Memoization

1986-largest-color-value-in-a-directed-graph
2028-the-earliest-and-latest-rounds-where-players-compete
2395-longest-binary-subsequence-less-than-or-equal-to-k
3733-length-of-longest-v-shaped-diagonal-segment

Union Find

1058-lexicographically-smallest-equivalent-string
1073-number-of-enclaves
1380-number-of-closed-islands
2582-minimum-score-of-a-path-between-two-cities

Trie

0208-implement-trie-prefix-tree
0386-lexicographical-numbers
0440-k-th-smallest-in-lexicographical-order
1350-remove-sub-folders-from-the-filesystem

Recursion

0021-merge-two-sorted-lists
0060-permutation-sequence
0143-reorder-list
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

Design

0208-implement-trie-prefix-tree
0297-serialize-and-deserialize-binary-tree
1995-finding-pairs-with-a-certain-sum
3678-design-task-manager
3797-design-spreadsheet
3827-implement-router

Linked List

0021-merge-two-sorted-lists
0143-reorder-list
0206-reverse-linked-list
0234-palindrome-linked-list
0908-middle-of-the-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer

Brainteaser

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

Probability and Statistics

0826-soup-servings
0867-new-21-game

Monotonic Stack

1628-count-submatrices-with-all-ones

Geometry

1266-minimum-time-visiting-all-points
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3625-count-number-of-trapezoids-ii

Line Sweep

3454-separate-squares-ii