LeetCode-problems

LeetCode problems solved to demonstrate and track progress

LeetCode Topics

Array

0001-two-sum
0011-container-with-most-water
0014-longest-common-prefix
0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0036-valid-sudoku
0042-trapping-rain-water
0045-jump-game-ii
0048-rotate-image
0049-group-anagrams
0054-spiral-matrix
0055-jump-game
0056-merge-intervals
0057-insert-interval
0063-unique-paths-ii
0064-minimum-path-sum
0066-plus-one
0068-text-justification
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0118-pascals-triangle
0119-pascals-triangle-ii
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0128-longest-consecutive-sequence
0130-surrounded-regions
0134-gas-station
0135-candy
0136-single-number
0137-single-number-ii
0139-word-break
0149-max-points-on-a-line
0150-evaluate-reverse-polish-notation
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0189-rotate-array
0198-house-robber
0200-number-of-islands
0209-minimum-size-subarray-sum
0212-word-search-ii
0215-kth-largest-element-in-an-array
0216-combination-sum-iii
0217-contains-duplicate
0219-contains-duplicate-ii
0228-summary-ranges
0238-product-of-array-except-self
0268-missing-number
0274-h-index
0283-move-zeroes
0289-game-of-life
0300-longest-increasing-subsequence
0303-range-sum-query-immutable
0322-coin-change
0334-increasing-triplet-subsequence
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0373-find-k-pairs-with-smallest-sums
0380-insert-delete-getrandom-o1
0399-evaluate-division
0414-third-maximum-number
0435-non-overlapping-intervals
0448-find-all-numbers-disappeared-in-an-array
0452-minimum-number-of-arrows-to-burst-balloons
0455-assign-cookies
0463-island-perimeter
0485-max-consecutive-ones
0502-ipo
0605-can-place-flowers
0643-maximum-average-subarray-i
0645-set-mismatch
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0724-find-pivot-index
0735-asteroid-collision
0739-daily-temperatures
0746-min-cost-climbing-stairs
0875-koko-eating-bananas
0994-rotting-oranges
1004-max-consecutive-ones-iii
1207-unique-number-of-occurrences
1268-search-suggestions-system
1391-check-if-there-is-a-valid-path-in-a-grid
1431-kids-with-the-greatest-number-of-candies
1493-longest-subarray-of-1s-after-deleting-one-element
1679-max-number-of-k-sum-pairs
1732-find-the-highest-altitude
1926-nearest-exit-from-entrance-in-maze
2033-minimum-operations-to-make-a-uni-value-grid
2215-find-the-difference-of-two-arrays
2300-successful-pairs-of-spells-and-potions
2352-equal-row-and-column-pairs
2462-total-cost-to-hire-k-workers
2542-maximum-subsequence-score
3225-maximum-score-from-grid-operations
3629-minimum-jumps-to-reach-end-via-prime-teleportation

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
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
0042-trapping-rain-water
0061-rotate-list
0080-remove-duplicates-from-sorted-array-ii
0082-remove-duplicates-from-sorted-list-ii
0086-partition-list
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0148-sort-list
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0202-happy-number
0234-palindrome-linked-list
0283-move-zeroes
0295-find-median-from-data-stream
0344-reverse-string
0345-reverse-vowels-of-a-string
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0392-is-subsequence
0443-string-compression
0455-assign-cookies
1679-max-number-of-k-sum-pairs
1768-merge-strings-alternately
2095-delete-the-middle-node-of-a-linked-list
2130-maximum-twin-sum-of-a-linked-list
2300-successful-pairs-of-spells-and-potions
2462-total-cost-to-hire-k-workers

Sorting

0015-3sum
0049-group-anagrams
0056-merge-intervals
0088-merge-sorted-array
0148-sort-list
0169-majority-element
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0242-valid-anagram
0268-missing-number
0274-h-index
0295-find-median-from-data-stream
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0389-find-the-difference
0414-third-maximum-number
0435-non-overlapping-intervals
0452-minimum-number-of-arrows-to-burst-balloons
0455-assign-cookies
0502-ipo
0645-set-mismatch
1268-search-suggestions-system
1657-determine-if-two-strings-are-close
1679-max-number-of-k-sum-pairs
2033-minimum-operations-to-make-a-uni-value-grid
2300-successful-pairs-of-spells-and-potions
2542-maximum-subsequence-score

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0030-substring-with-concatenation-of-all-words
0036-valid-sudoku
0049-group-anagrams
0073-set-matrix-zeroes
0076-minimum-window-substring
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0128-longest-consecutive-sequence
0133-clone-graph
0138-copy-list-with-random-pointer
0139-word-break
0141-linked-list-cycle
0146-lru-cache
0149-max-points-on-a-line
0160-intersection-of-two-linked-lists
0169-majority-element
0202-happy-number
0205-isomorphic-strings
0208-implement-trie-prefix-tree
0217-contains-duplicate
0219-contains-duplicate-ii
0242-valid-anagram
0268-missing-number
0290-word-pattern
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0380-insert-delete-getrandom-o1
0383-ransom-note
0387-first-unique-character-in-a-string
0389-find-the-difference
0433-minimum-genetic-mutation
0448-find-all-numbers-disappeared-in-an-array
0645-set-mismatch
1207-unique-number-of-occurrences
1657-determine-if-two-strings-are-close
1679-max-number-of-k-sum-pairs
2215-find-the-difference-of-two-arrays
2336-smallest-number-in-infinite-set
2352-equal-row-and-column-pairs
3120-count-the-number-of-special-characters-i
3629-minimum-jumps-to-reach-end-via-prime-teleportation

Divide and Conquer

0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0148-sort-list
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits
0215-kth-largest-element-in-an-array

Counting

0169-majority-element
0383-ransom-note
0387-first-unique-character-in-a-string
1657-determine-if-two-strings-are-close

Math

0002-add-two-numbers
0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0048-rotate-image
0050-powx-n
0062-unique-paths
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0149-max-points-on-a-line
0150-evaluate-reverse-polish-notation
0168-excel-sheet-column-title
0172-factorial-trailing-zeroes
0189-rotate-array
0202-happy-number
0231-power-of-two
0258-add-digits
0263-ugly-number
0268-missing-number
0292-nim-game
0326-power-of-three
0342-power-of-four
0367-valid-perfect-square
0380-insert-delete-getrandom-o1
0412-fizz-buzz
0415-add-strings
0492-construct-the-rectangle
1071-greatest-common-divisor-of-strings
1137-n-th-tribonacci-number
2033-minimum-operations-to-make-a-uni-value-grid
3629-minimum-jumps-to-reach-end-via-prime-teleportation

Dynamic Programming

0005-longest-palindromic-substring
0042-trapping-rain-water
0045-jump-game-ii
0055-jump-game
0062-unique-paths
0063-unique-paths-ii
0064-minimum-path-sum
0070-climbing-stairs
0072-edit-distance
0118-pascals-triangle
0119-pascals-triangle-ii
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0139-word-break
0198-house-robber
0300-longest-increasing-subsequence
0322-coin-change
0338-counting-bits
0392-is-subsequence
0435-non-overlapping-intervals
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0746-min-cost-climbing-stairs
0790-domino-and-tromino-tiling
1137-n-th-tribonacci-number
1143-longest-common-subsequence
1372-longest-zigzag-path-in-a-binary-tree
1493-longest-subarray-of-1s-after-deleting-one-element
3225-maximum-score-from-grid-operations

Greedy

0011-container-with-most-water
0045-jump-game-ii
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0135-candy
0334-increasing-triplet-subsequence
0435-non-overlapping-intervals
0452-minimum-number-of-arrows-to-burst-balloons
0455-assign-cookies
0502-ipo
0605-can-place-flowers
0649-dota2-senate
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
2542-maximum-subsequence-score

Counting Sort

0274-h-index

Design

0146-lru-cache
0155-min-stack
0173-binary-search-tree-iterator
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0295-find-median-from-data-stream
0303-range-sum-query-immutable
0380-insert-delete-getrandom-o1
0901-online-stock-span
0933-number-of-recent-calls
2336-smallest-number-in-infinite-set

Randomized

0380-insert-delete-getrandom-o1

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0303-range-sum-query-immutable
0724-find-pivot-index
1004-max-consecutive-ones-iii
1732-find-the-highest-altitude
3225-maximum-score-from-grid-operations

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0006-zigzag-conversion
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0020-valid-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0030-substring-with-concatenation-of-all-words
0049-group-anagrams
0058-length-of-last-word
0067-add-binary
0068-text-justification
0071-simplify-path
0072-edit-distance
0076-minimum-window-substring
0125-valid-palindrome
0139-word-break
0151-reverse-words-in-a-string
0168-excel-sheet-column-title
0205-isomorphic-strings
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0212-word-search-ii
0242-valid-anagram
0257-binary-tree-paths
0290-word-pattern
0344-reverse-string
0345-reverse-vowels-of-a-string
0383-ransom-note
0387-first-unique-character-in-a-string
0389-find-the-difference
0392-is-subsequence
0394-decode-string
0399-evaluate-division
0412-fizz-buzz
0415-add-strings
0433-minimum-genetic-mutation
0434-number-of-segments-in-a-string
0443-string-compression
0482-license-key-formatting
0649-dota2-senate
1071-greatest-common-divisor-of-strings
1143-longest-common-subsequence
1268-search-suggestions-system
1456-maximum-number-of-vowels-in-a-substring-of-given-length
1657-determine-if-two-strings-are-close
1768-merge-strings-alternately
2390-removing-stars-from-a-string
3120-count-the-number-of-special-characters-i

Trie

0014-longest-common-prefix
0139-word-break
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0212-word-search-ii
1268-search-suggestions-system

String Matching

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

Simulation

0054-spiral-matrix
0067-add-binary
0068-text-justification
0258-add-digits
0289-game-of-life
0412-fizz-buzz
0415-add-strings
0735-asteroid-collision
2352-equal-row-and-column-pairs
2390-removing-stars-from-a-string
2462-total-cost-to-hire-k-workers

Stack

0020-valid-parentheses
0042-trapping-rain-water
0071-simplify-path
0094-binary-tree-inorder-traversal
0114-flatten-binary-tree-to-linked-list
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0150-evaluate-reverse-polish-notation
0155-min-stack
0173-binary-search-tree-iterator
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0394-decode-string
0735-asteroid-collision
0739-daily-temperatures
0901-online-stock-span
2130-maximum-twin-sum-of-a-linked-list
2390-removing-stars-from-a-string

Monotonic Stack

0042-trapping-rain-water
0739-daily-temperatures
0901-online-stock-span

Binary Search

0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0069-sqrtx
0074-search-a-2d-matrix
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0222-count-complete-tree-nodes
0268-missing-number
0278-first-bad-version
0300-longest-increasing-subsequence
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0367-valid-perfect-square
0374-guess-number-higher-or-lower
0875-koko-eating-bananas
1004-max-consecutive-ones-iii
1268-search-suggestions-system
2300-successful-pairs-of-spells-and-potions

Sliding Window

0003-longest-substring-without-repeating-characters
0030-substring-with-concatenation-of-all-words
0076-minimum-window-substring
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0643-maximum-average-subarray-i
1004-max-consecutive-ones-iii
1456-maximum-number-of-vowels-in-a-substring-of-given-length
1493-longest-subarray-of-1s-after-deleting-one-element

Matrix

0036-valid-sudoku
0048-rotate-image
0054-spiral-matrix
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0130-surrounded-regions
0200-number-of-islands
0212-word-search-ii
0289-game-of-life
0463-island-perimeter
0994-rotting-oranges
1391-check-if-there-is-a-valid-path-in-a-grid
1926-nearest-exit-from-entrance-in-maze
2033-minimum-operations-to-make-a-uni-value-grid
2352-equal-row-and-column-pairs
3225-maximum-score-from-grid-operations

Union Find

0128-longest-consecutive-sequence

Database

0175-combine-two-tables
1757-recyclable-and-low-fat-products

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0025-reverse-nodes-in-k-group
0061-rotate-list
0082-remove-duplicates-from-sorted-list-ii
0083-remove-duplicates-from-sorted-list
0086-partition-list
0092-reverse-linked-list-ii
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0138-copy-list-with-random-pointer
0141-linked-list-cycle
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
0328-odd-even-linked-list
2095-delete-the-middle-node-of-a-linked-list
2130-maximum-twin-sum-of-a-linked-list

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0025-reverse-nodes-in-k-group
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
0394-decode-string

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
0111-minimum-depth-of-binary-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
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
0236-lowest-common-ancestor-of-a-binary-tree
0257-binary-tree-paths
0404-sum-of-left-leaves
0437-path-sum-iii
0450-delete-node-in-a-bst
0530-minimum-absolute-difference-in-bst
0637-average-of-levels-in-binary-tree
0700-search-in-a-binary-search-tree
0872-leaf-similar-trees
1161-maximum-level-sum-of-a-binary-tree
1372-longest-zigzag-path-in-a-binary-tree
1448-count-good-nodes-in-binary-tree

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
0111-minimum-depth-of-binary-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0129-sum-root-to-leaf-numbers
0130-surrounded-regions
0133-clone-graph
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0211-design-add-and-search-words-data-structure
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0257-binary-tree-paths
0399-evaluate-division
0404-sum-of-left-leaves
0437-path-sum-iii
0463-island-perimeter
0530-minimum-absolute-difference-in-bst
0547-number-of-provinces
0637-average-of-levels-in-binary-tree
0841-keys-and-rooms
0872-leaf-similar-trees
1161-maximum-level-sum-of-a-binary-tree
1372-longest-zigzag-path-in-a-binary-tree
1391-check-if-there-is-a-valid-path-in-a-grid
1448-count-good-nodes-in-binary-tree
1466-reorder-routes-to-make-all-paths-lead-to-the-city-zero

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
0111-minimum-depth-of-binary-tree
0112-path-sum
0117-populating-next-right-pointers-in-each-node-ii
0130-surrounded-regions
0133-clone-graph
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0226-invert-binary-tree
0322-coin-change
0399-evaluate-division
0404-sum-of-left-leaves
0433-minimum-genetic-mutation
0463-island-perimeter
0530-minimum-absolute-difference-in-bst
0547-number-of-provinces
0637-average-of-levels-in-binary-tree
0841-keys-and-rooms
0994-rotting-oranges
1161-maximum-level-sum-of-a-binary-tree
1391-check-if-there-is-a-valid-path-in-a-grid
1448-count-good-nodes-in-binary-tree
1466-reorder-routes-to-make-all-paths-lead-to-the-city-zero
1926-nearest-exit-from-entrance-in-maze
3629-minimum-jumps-to-reach-end-via-prime-teleportation

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
0111-minimum-depth-of-binary-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
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
0236-lowest-common-ancestor-of-a-binary-tree
0257-binary-tree-paths
0404-sum-of-left-leaves
0437-path-sum-iii
0450-delete-node-in-a-bst
0530-minimum-absolute-difference-in-bst
0637-average-of-levels-in-binary-tree
0700-search-in-a-binary-search-tree
0872-leaf-similar-trees
1161-maximum-level-sum-of-a-binary-tree
1372-longest-zigzag-path-in-a-binary-tree
1448-count-good-nodes-in-binary-tree

Binary Search Tree

0098-validate-binary-search-tree
0108-convert-sorted-array-to-binary-search-tree
0173-binary-search-tree-iterator
0230-kth-smallest-element-in-a-bst
0450-delete-node-in-a-bst
0530-minimum-absolute-difference-in-bst
0700-search-in-a-binary-search-tree

Union-Find

0130-surrounded-regions
0200-number-of-islands
0399-evaluate-division
0547-number-of-provinces
1391-check-if-there-is-a-valid-path-in-a-grid

Doubly-Linked List

0146-lru-cache

Bit Manipulation

0067-add-binary
0136-single-number
0137-single-number-ii
0190-reverse-bits
0191-number-of-1-bits
0201-bitwise-and-of-numbers-range
0222-count-complete-tree-nodes
0231-power-of-two
0268-missing-number
0338-counting-bits
0342-power-of-four
0389-find-the-difference
0401-binary-watch
0461-hamming-distance
0645-set-mismatch
1318-minimum-flips-to-make-a-or-b-equal-to-c

Graph Theory

0133-clone-graph
0207-course-schedule
0210-course-schedule-ii
0399-evaluate-division
0547-number-of-provinces
0841-keys-and-rooms
1466-reorder-routes-to-make-all-paths-lead-to-the-city-zero

Memoization

0070-climbing-stairs
0139-word-break
1137-n-th-tribonacci-number

Shortest Path

0399-evaluate-division

Topological Sort

0207-course-schedule
0210-course-schedule-ii

Iterator

0173-binary-search-tree-iterator

Merge Sort

0148-sort-list

Geometry

0149-max-points-on-a-line

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0387-first-unique-character-in-a-string
0649-dota2-senate
0933-number-of-recent-calls

Data Stream

0295-find-median-from-data-stream
0901-online-stock-span
0933-number-of-recent-calls

Interactive

0278-first-bad-version
0374-guess-number-higher-or-lower

Combinatorics

0062-unique-paths

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0295-find-median-from-data-stream
0373-find-k-pairs-with-smallest-sums
0502-ipo
1268-search-suggestions-system
2336-smallest-number-in-infinite-set
2462-total-cost-to-hire-k-workers
2542-maximum-subsequence-score

Quickselect

0215-kth-largest-element-in-an-array

Ordered Set

2336-smallest-number-in-infinite-set

Backtracking

0017-letter-combinations-of-a-phone-number
0077-combinations
0212-word-search-ii
0216-combination-sum-iii
0257-binary-tree-paths
0401-binary-watch

Number Theory

0258-add-digits
3629-minimum-jumps-to-reach-end-via-prime-teleportation

Brainteaser

0292-nim-game

Game Theory

0292-nim-game