leetcode

A collection of Leetcode problems I solve. Checkout my LeetCode profile here.

LeetCode Topics

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0036-valid-sudoku
0042-trapping-rain-water
0045-jump-game-ii
0048-rotate-image
0049-group-anagrams
0051-n-queens
0054-spiral-matrix
0056-merge-intervals
0057-insert-interval
0066-plus-one
0074-search-a-2d-matrix
0075-sort-colors
0078-subsets
0079-word-search
0084-largest-rectangle-in-histogram
0088-merge-sorted-array
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0134-gas-station
0136-single-number
0139-word-break
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
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
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0219-contains-duplicate-ii
0238-product-of-array-except-self
0252-meeting-rooms
0253-meeting-rooms-ii
0260-single-number-iii
0268-missing-number
0283-move-zeroes
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0334-increasing-triplet-subsequence
0347-top-k-frequent-elements
0380-insert-delete-getrandom-o1
0435-non-overlapping-intervals
0496-next-greater-element-i
0560-subarray-sum-equals-k
0658-find-k-closest-elements
0682-baseball-game
0792-binary-search
0817-design-hashmap
0882-peak-index-in-a-mountain-array
0883-car-fleet
0907-koko-eating-bananas
0917-boats-to-save-people
1014-k-closest-points-to-origin
1036-rotting-oranges
1074-high-five
1108-analyze-user-website-visit-pattern
1127-last-stone-weight
1306-minimum-absolute-difference
1364-tuple-with-same-product
1397-search-suggestions-system
1428-jump-game-iii
1627-last-moment-before-all-ants-fall-out-of-a-plank
1878-check-if-array-is-sorted-and-rotated
1927-maximum-ascending-subarray-sum
2362-minimum-rounds-to-complete-all-tasks
2436-make-array-zero-by-subtracting-equal-amounts
2547-odd-string-difference
2707-merge-two-2d-arrays-by-summing-values
3220-count-tested-devices-after-test-operations
3227-find-missing-and-repeated-values
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3429-special-array-i
3434-find-the-number-of-distinct-colors-among-the-balls
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3579-maximum-possible-number-by-binary-concatenation

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
0036-valid-sudoku
0049-group-anagrams
0128-longest-consecutive-sequence
0138-copy-list-with-random-pointer
0139-word-break
0141-linked-list-cycle
0146-lru-cache
0169-majority-element
0217-contains-duplicate
0219-contains-duplicate-ii
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
0355-design-twitter
0380-insert-delete-getrandom-o1
0387-first-unique-character-in-a-string
0424-longest-repeating-character-replacement
0460-lfu-cache
0496-next-greater-element-i
0560-subarray-sum-equals-k
0567-permutation-in-string
0778-reorganize-string
0817-design-hashmap
0931-maximum-frequency-stack
1023-time-based-key-value-store
1074-high-five
1108-analyze-user-website-visit-pattern
1364-tuple-with-same-product
1915-check-if-one-string-swap-can-make-strings-equal
2362-minimum-rounds-to-complete-all-tasks
2436-make-array-zero-by-subtracting-equal-amounts
2547-odd-string-difference
2707-merge-two-2d-arrays-by-summing-values
3227-find-missing-and-repeated-values
3434-find-the-number-of-distinct-colors-among-the-balls

String

0003-longest-substring-without-repeating-characters
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
0022-generate-parentheses
0049-group-anagrams
0071-simplify-path
0079-word-search
0125-valid-palindrome
0139-word-break
0242-valid-anagram
0344-reverse-string
0387-first-unique-character-in-a-string
0394-decode-string
0412-fizz-buzz
0424-longest-repeating-character-replacement
0567-permutation-in-string
0680-valid-palindrome-ii
0778-reorganize-string
1023-time-based-key-value-store
1208-maximum-nesting-depth-of-two-valid-parentheses-strings
1371-minimum-remove-to-make-valid-parentheses
1397-search-suggestions-system
1537-maximum-score-after-splitting-a-string
1894-merge-strings-alternately
1915-check-if-one-string-swap-can-make-strings-equal
2128-reverse-prefix-of-word
2547-odd-string-difference
2800-minimum-string-length-after-removing-substrings

Sorting

0049-group-anagrams
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0242-valid-anagram
0252-meeting-rooms
0253-meeting-rooms-ii
0268-missing-number
0347-top-k-frequent-elements
0435-non-overlapping-intervals
0658-find-k-closest-elements
0778-reorganize-string
0883-car-fleet
0917-boats-to-save-people
1014-k-closest-points-to-origin
1074-high-five
1108-analyze-user-website-visit-pattern
1306-minimum-absolute-difference
1397-search-suggestions-system
2436-make-array-zero-by-subtracting-equal-amounts

Divide and Conquer

0004-median-of-two-sorted-arrays
0023-merge-k-sorted-lists
0169-majority-element
0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
1014-k-closest-points-to-origin

Heap (Priority Queue)

0023-merge-k-sorted-lists
0215-kth-largest-element-in-an-array
0253-meeting-rooms-ii
0347-top-k-frequent-elements
0355-design-twitter
0658-find-k-closest-elements
0778-reorganize-string
1014-k-closest-points-to-origin
1074-high-five
1127-last-stone-weight
1397-search-suggestions-system
2436-make-array-zero-by-subtracting-equal-amounts

Bucket Sort

0347-top-k-frequent-elements

Counting

0169-majority-element
0347-top-k-frequent-elements
0387-first-unique-character-in-a-string
0778-reorganize-string
1364-tuple-with-same-product
1915-check-if-one-string-swap-can-make-strings-equal
2362-minimum-rounds-to-complete-all-tasks
3220-count-tested-devices-after-test-operations

Quickselect

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
1014-k-closest-points-to-origin

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0253-meeting-rooms-ii
0560-subarray-sum-equals-k
1537-maximum-score-after-splitting-a-string

Two Pointers

0011-container-with-most-water
0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0042-trapping-rain-water
0075-sort-colors
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0143-reorder-list
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0234-palindrome-linked-list
0253-meeting-rooms-ii
0283-move-zeroes
0287-find-the-duplicate-number
0344-reverse-string
0567-permutation-in-string
0658-find-k-closest-elements
0680-valid-palindrome-ii
0908-middle-of-the-linked-list
0917-boats-to-save-people
1894-merge-strings-alternately
2128-reverse-prefix-of-word
2707-merge-two-2d-arrays-by-summing-values

Matrix

0036-valid-sudoku
0048-rotate-image
0054-spiral-matrix
0074-search-a-2d-matrix
0079-word-search
0200-number-of-islands
1036-rotting-oranges
3227-find-missing-and-repeated-values

Union Find

0128-longest-consecutive-sequence
0200-number-of-islands

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0069-sqrtx
0074-search-a-2d-matrix
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0268-missing-number
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0374-guess-number-higher-or-lower
0658-find-k-closest-elements
0792-binary-search
0882-peak-index-in-a-mountain-array
0907-koko-eating-bananas
1023-time-based-key-value-store
1397-search-suggestions-system

Greedy

0011-container-with-most-water
0045-jump-game-ii
0134-gas-station
0253-meeting-rooms-ii
0334-increasing-triplet-subsequence
0435-non-overlapping-intervals
0680-valid-palindrome-ii
0778-reorganize-string
0917-boats-to-save-people
2362-minimum-rounds-to-complete-all-tasks
2436-make-array-zero-by-subtracting-equal-amounts

Stack

0020-valid-parentheses
0042-trapping-rain-water
0071-simplify-path
0084-largest-rectangle-in-histogram
0114-flatten-binary-tree-to-linked-list
0143-reorder-list
0144-binary-tree-preorder-traversal
0155-min-stack
0234-palindrome-linked-list
0394-decode-string
0496-next-greater-element-i
0682-baseball-game
0883-car-fleet
0931-maximum-frequency-stack
0937-online-stock-span
1208-maximum-nesting-depth-of-two-valid-parentheses-strings
1371-minimum-remove-to-make-valid-parentheses
2128-reverse-prefix-of-word
2800-minimum-string-length-after-removing-substrings

Design

0146-lru-cache
0155-min-stack
0355-design-twitter
0380-insert-delete-getrandom-o1
0460-lfu-cache
0817-design-hashmap
0931-maximum-frequency-stack
0937-online-stock-span
1023-time-based-key-value-store

Sliding Window

0003-longest-substring-without-repeating-characters
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0424-longest-repeating-character-replacement
0567-permutation-in-string
0658-find-k-closest-elements

Dynamic Programming

0022-generate-parentheses
0042-trapping-rain-water
0045-jump-game-ii
0062-unique-paths
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0139-word-break
0152-maximum-product-subarray
0198-house-robber
0300-longest-increasing-subsequence
0435-non-overlapping-intervals
1013-fibonacci-number

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0051-n-queens
0078-subsets
0079-word-search

Simulation

0054-spiral-matrix
0412-fizz-buzz
0682-baseball-game
1627-last-moment-before-all-ants-fall-out-of-a-plank
2436-make-array-zero-by-subtracting-equal-amounts
2800-minimum-string-length-after-removing-substrings
3220-count-tested-devices-after-test-operations
3434-find-the-number-of-distinct-colors-among-the-balls

Brainteaser

1627-last-moment-before-all-ants-fall-out-of-a-plank

Linked List

0002-add-two-numbers
0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0114-flatten-binary-tree-to-linked-list
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0143-reorder-list
0146-lru-cache
0206-reverse-linked-list
0234-palindrome-linked-list
0355-design-twitter
0460-lfu-cache
0817-design-hashmap
0908-middle-of-the-linked-list

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0050-powx-n
0143-reorder-list
0206-reverse-linked-list
0234-palindrome-linked-list
0394-decode-string
1013-fibonacci-number

Tree

0100-same-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0144-binary-tree-preorder-traversal
0199-binary-tree-right-side-view
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0572-subtree-of-another-tree

Depth-First Search

0079-word-search
0100-same-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0144-binary-tree-preorder-traversal
0199-binary-tree-right-side-view
0200-number-of-islands
0210-course-schedule-ii
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0572-subtree-of-another-tree
1428-jump-game-iii

Binary Tree

0100-same-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0144-binary-tree-preorder-traversal
0199-binary-tree-right-side-view
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0572-subtree-of-another-tree

Bit Manipulation

0078-subsets
0136-single-number
0260-single-number-iii
0268-missing-number
0287-find-the-duplicate-number
3579-maximum-possible-number-by-binary-concatenation

Enumeration

3579-maximum-possible-number-by-binary-concatenation

Breadth-First Search

0100-same-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0199-binary-tree-right-side-view
0200-number-of-islands
0210-course-schedule-ii
0226-invert-binary-tree
1036-rotting-oranges
1428-jump-game-iii

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0496-next-greater-element-i
0883-car-fleet
0937-online-stock-span

Interactive

0374-guess-number-higher-or-lower

Database

1908-recyclable-and-low-fat-products

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0048-rotate-image
0050-powx-n
0062-unique-paths
0066-plus-one
0069-sqrtx
0189-rotate-array
0268-missing-number
0380-insert-delete-getrandom-o1
0412-fizz-buzz
1013-fibonacci-number
1014-k-closest-points-to-origin
1585-the-kth-factor-of-n
3227-find-missing-and-repeated-values
3476-find-minimum-operations-to-make-all-elements-divisible-by-three

Queue

0387-first-unique-character-in-a-string

Doubly-Linked List

0146-lru-cache
0460-lfu-cache

Randomized

0380-insert-delete-getrandom-o1

Binary Search Tree

0235-lowest-common-ancestor-of-a-binary-search-tree

Graph

0210-course-schedule-ii

Topological Sort

0210-course-schedule-ii

Merge Sort

0023-merge-k-sorted-lists

Trie

0014-longest-common-prefix
0139-word-break
1397-search-suggestions-system

Memoization

0139-word-break
1013-fibonacci-number

Combinatorics

0062-unique-paths

String Matching

0572-subtree-of-another-tree

Hash Function

0572-subtree-of-another-tree
0817-design-hashmap

Geometry

1014-k-closest-points-to-origin

Number Theory

1585-the-kth-factor-of-n

Data Stream

0937-online-stock-span

Ordered Set

0931-maximum-frequency-stack