Code from my leetcode and hackerrank solutions.

LeetCode Topics

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
0015-3sum
0033-search-in-rotated-sorted-array
0036-valid-sudoku
0042-trapping-rain-water
0048-rotate-image
0074-search-a-2d-matrix
0084-largest-rectangle-in-histogram
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0150-evaluate-reverse-polish-notation
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0200-number-of-islands
0238-product-of-array-except-self
0239-sliding-window-maximum
0240-search-a-2d-matrix-ii
0268-missing-number
0560-subarray-sum-equals-k
0704-binary-search
0733-flood-fill
0739-daily-temperatures
0804-unique-morse-code-words
0853-car-fleet
0875-koko-eating-bananas
1266-minimum-time-visiting-all-points
1356-sort-integers-by-the-number-of-1-bits
1390-four-divisors
1582-special-positions-in-a-binary-matrix
1752-check-if-array-is-sorted-and-rotated
1855-maximum-distance-between-a-pair-of-values
1861-rotating-the-box
1886-determine-whether-matrix-can-be-obtained-by-rotation
1975-maximum-matrix-sum
2078-two-furthest-houses-with-different-colors
2090-k-radius-subarray-averages
2191-sort-the-jumbled-numbers
2200-find-all-k-distant-indices-in-an-array
2515-shortest-distance-to-target-string-in-a-circular-array
2540-minimum-common-value
2553-separate-the-digits-in-an-array
2906-construct-product-matrix
2946-matrix-similarity-after-cyclic-shifts
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3070-count-submatrices-with-top-left-element-and-sum-less-than-k
3158-find-the-xor-of-numbers-which-appear-twice
3212-count-submatrices-with-equal-frequency-of-x-and-y
3314-construct-the-minimum-bitwise-array-i
3379-transformed-array
3633-earliest-finish-time-for-land-and-water-rides-i
3634-minimum-removals-to-balance-array
3637-trionic-array-i
3668-restore-finishing-order
3719-longest-balanced-subarray-i
3761-minimum-absolute-distance-between-mirror-pairs
3766-minimum-operations-to-make-binary-palindrome

Prefix Sum

0238-product-of-array-except-self
0560-subarray-sum-equals-k
2906-construct-product-matrix
3070-count-submatrices-with-top-left-element-and-sum-less-than-k
3212-count-submatrices-with-equal-frequency-of-x-and-y
3714-longest-balanced-substring-ii
3719-longest-balanced-subarray-i

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0036-valid-sudoku
0076-minimum-window-substring
0128-longest-consecutive-sequence
0141-linked-list-cycle
0169-majority-element
0268-missing-number
0387-first-unique-character-in-a-string
0424-longest-repeating-character-replacement
0560-subarray-sum-equals-k
0567-permutation-in-string
0804-unique-morse-code-words
0865-smallest-subtree-with-all-the-deepest-nodes
0981-time-based-key-value-store
1461-check-if-a-string-contains-all-binary-codes-of-size-k
2540-minimum-common-value
2840-check-if-strings-can-be-made-equal-with-operations-ii
3158-find-the-xor-of-numbers-which-appear-twice
3541-find-most-frequent-vowel-and-consonant
3668-restore-finishing-order
3713-longest-balanced-substring-i
3714-longest-balanced-substring-ii
3719-longest-balanced-subarray-i
3761-minimum-absolute-distance-between-mirror-pairs

Matrix

0036-valid-sudoku
0048-rotate-image
0074-search-a-2d-matrix
0200-number-of-islands
0240-search-a-2d-matrix-ii
0733-flood-fill
1582-special-positions-in-a-binary-matrix
1861-rotating-the-box
1886-determine-whether-matrix-can-be-obtained-by-rotation
1975-maximum-matrix-sum
2906-construct-product-matrix
2946-matrix-similarity-after-cyclic-shifts
3070-count-submatrices-with-top-left-element-and-sum-less-than-k
3212-count-submatrices-with-equal-frequency-of-x-and-y

Two Pointers

0011-container-with-most-water
0015-3sum
0019-remove-nth-node-from-end-of-list
0042-trapping-rain-water
0061-rotate-list
0141-linked-list-cycle
0143-reorder-list
0167-two-sum-ii-input-array-is-sorted
0567-permutation-in-string
0696-count-binary-substrings
1855-maximum-distance-between-a-pair-of-values
1861-rotating-the-box
2200-find-all-k-distant-indices-in-an-array
2540-minimum-common-value
3633-earliest-finish-time-for-land-and-water-rides-i
3766-minimum-operations-to-make-binary-palindrome

String

0003-longest-substring-without-repeating-characters
0020-valid-parentheses
0067-add-binary
0076-minimum-window-substring
0387-first-unique-character-in-a-string
0424-longest-repeating-character-replacement
0567-permutation-in-string
0657-robot-return-to-origin
0696-count-binary-substrings
0796-rotate-string
0804-unique-morse-code-words
0981-time-based-key-value-store
1404-number-of-steps-to-reduce-a-number-in-binary-representation-to-one
1461-check-if-a-string-contains-all-binary-codes-of-size-k
1689-partitioning-into-minimum-number-of-deci-binary-numbers
2515-shortest-distance-to-target-string-in-a-circular-array
2833-furthest-point-from-origin
2839-check-if-strings-can-be-made-equal-with-operations-i
2840-check-if-strings-can-be-made-equal-with-operations-ii
3541-find-most-frequent-vowel-and-consonant
3713-longest-balanced-substring-i
3714-longest-balanced-substring-ii

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0239-sliding-window-maximum
0424-longest-repeating-character-replacement
0567-permutation-in-string
2090-k-radius-subarray-averages
3634-minimum-removals-to-balance-array

Union Find

0128-longest-consecutive-sequence

Math

0048-rotate-image
0067-add-binary
0150-evaluate-reverse-polish-notation
0268-missing-number
0788-rotated-digits
1266-minimum-time-visiting-all-points
1390-four-divisors
2946-matrix-similarity-after-cyclic-shifts
3761-minimum-absolute-distance-between-mirror-pairs

Greedy

0011-container-with-most-water
1382-balance-a-binary-search-tree
1689-partitioning-into-minimum-number-of-deci-binary-numbers
1975-maximum-matrix-sum
2078-two-furthest-houses-with-different-colors
3633-earliest-finish-time-for-land-and-water-rides-i

Stack

0020-valid-parentheses
0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0094-binary-tree-inorder-traversal
0143-reorder-list
0145-binary-tree-postorder-traversal
0150-evaluate-reverse-polish-notation
0155-min-stack
0739-daily-temperatures
0853-car-fleet

Tree

0094-binary-tree-inorder-traversal
0102-binary-tree-level-order-traversal
0110-balanced-binary-tree
0145-binary-tree-postorder-traversal
0563-binary-tree-tilt
0865-smallest-subtree-with-all-the-deepest-nodes
1161-maximum-level-sum-of-a-binary-tree
1339-maximum-product-of-splitted-binary-tree
1382-balance-a-binary-search-tree

Depth-First Search

0094-binary-tree-inorder-traversal
0110-balanced-binary-tree
0145-binary-tree-postorder-traversal
0200-number-of-islands
0207-course-schedule
0547-number-of-provinces
0563-binary-tree-tilt
0733-flood-fill
0865-smallest-subtree-with-all-the-deepest-nodes
1161-maximum-level-sum-of-a-binary-tree
1339-maximum-product-of-splitted-binary-tree
1382-balance-a-binary-search-tree
1971-find-if-path-exists-in-graph

Binary Tree

0094-binary-tree-inorder-traversal
0102-binary-tree-level-order-traversal
0110-balanced-binary-tree
0145-binary-tree-postorder-traversal
0563-binary-tree-tilt
0865-smallest-subtree-with-all-the-deepest-nodes
1161-maximum-level-sum-of-a-binary-tree
1339-maximum-product-of-splitted-binary-tree
1382-balance-a-binary-search-tree

Breadth-First Search

0102-binary-tree-level-order-traversal
0200-number-of-islands
0207-course-schedule
0547-number-of-provinces
0733-flood-fill
0865-smallest-subtree-with-all-the-deepest-nodes
1161-maximum-level-sum-of-a-binary-tree
1971-find-if-path-exists-in-graph

Sorting

0015-3sum
0169-majority-element
0268-missing-number
0853-car-fleet
1356-sort-integers-by-the-number-of-1-bits
2191-sort-the-jumbled-numbers
2840-check-if-strings-can-be-made-equal-with-operations-ii
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3633-earliest-finish-time-for-land-and-water-rides-i
3634-minimum-removals-to-balance-array

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0074-search-a-2d-matrix
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0240-search-a-2d-matrix-ii
0268-missing-number
0704-binary-search
0875-koko-eating-bananas
0981-time-based-key-value-store
1855-maximum-distance-between-a-pair-of-values
2540-minimum-common-value
3633-earliest-finish-time-for-land-and-water-rides-i
3766-minimum-operations-to-make-binary-palindrome

Bit Manipulation

0067-add-binary
0190-reverse-bits
0191-number-of-1-bits
0268-missing-number
0868-binary-gap
1356-sort-integers-by-the-number-of-1-bits
1404-number-of-steps-to-reduce-a-number-in-binary-representation-to-one
1461-check-if-a-string-contains-all-binary-codes-of-size-k
3158-find-the-xor-of-numbers-which-appear-twice
3314-construct-the-minimum-bitwise-array-i
3766-minimum-operations-to-make-binary-palindrome

Counting

0169-majority-element
0387-first-unique-character-in-a-string
1356-sort-integers-by-the-number-of-1-bits
2833-furthest-point-from-origin
3541-find-most-frequent-vowel-and-consonant
3713-longest-balanced-substring-i

Geometry

1266-minimum-time-visiting-all-points

Divide and Conquer

0004-median-of-two-sorted-arrays
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits
0240-search-a-2d-matrix-ii
1382-balance-a-binary-search-tree
3719-longest-balanced-subarray-i

Dynamic Programming

0042-trapping-rain-water
0121-best-time-to-buy-and-sell-stock
0788-rotated-digits

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0739-daily-temperatures
0853-car-fleet

Enumeration

3010-divide-an-array-into-subarrays-with-minimum-cost-i
3713-longest-balanced-substring-i

Simulation

0067-add-binary
0657-robot-return-to-origin
1404-number-of-steps-to-reduce-a-number-in-binary-representation-to-one
2553-separate-the-digits-in-an-array
2946-matrix-similarity-after-cyclic-shifts
3379-transformed-array

Binary Search Tree

1382-balance-a-binary-search-tree

Segment Tree

3719-longest-balanced-subarray-i

Database

0175-combine-two-tables
0181-employees-earning-more-than-their-managers
0182-duplicate-emails
0570-managers-with-at-least-5-direct-reports

Queue

0239-sliding-window-maximum
0387-first-unique-character-in-a-string

Rolling Hash

1461-check-if-a-string-contains-all-binary-codes-of-size-k

Hash Function

1461-check-if-a-string-contains-all-binary-codes-of-size-k

Heap (Priority Queue)

0239-sliding-window-maximum

Monotonic Queue

0239-sliding-window-maximum

Design

0155-min-stack
0981-time-based-key-value-store

Linked List

0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0061-rotate-list
0141-linked-list-cycle
0143-reorder-list
0206-reverse-linked-list

Recursion

0021-merge-two-sorted-lists
0143-reorder-list
0206-reverse-linked-list

String Matching

0796-rotate-string

Graph Theory

0207-course-schedule
0547-number-of-provinces
1791-find-center-of-star-graph
1971-find-if-path-exists-in-graph

Topological Sort

0207-course-schedule

Union-Find

0200-number-of-islands
0547-number-of-provinces
1971-find-if-path-exists-in-graph