My Solutions for Leet Code Problems

LeetCode Topics

Hash Table

0003-longest-substring-without-repeating-characters
0036-valid-sudoku
0133-clone-graph
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0146-lru-cache
0202-happy-number
0219-contains-duplicate-ii
0496-next-greater-element-i
0525-contiguous-array
0822-unique-morse-code-words
0840-magic-squares-in-grid
0952-word-subsets
1500-count-largest-group
1715-split-a-string-into-the-max-number-of-unique-substrings
1915-check-if-one-string-swap-can-make-strings-equal
1995-finding-pairs-with-a-certain-sum
2308-divide-array-into-equal-pairs
2356-largest-combination-with-bitwise-and-greater-than-zero
2442-number-of-arithmetic-triplets
2586-longest-square-streak-in-an-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
2707-merge-two-2d-arrays-by-summing-values
3412-permutation-difference-between-two-strings
3446-find-the-number-of-good-pairs-i
3753-maximum-difference-between-even-and-odd-frequency-i

String

0003-longest-substring-without-repeating-characters
0014-longest-common-prefix
0028-find-the-index-of-the-first-occurrence-in-a-string
0071-simplify-path
0822-unique-morse-code-words
0952-word-subsets
1197-parsing-a-boolean-expression
1302-delete-characters-to-make-fancy-string
1341-split-a-string-in-balanced-strings
1350-remove-sub-folders-from-the-filesystem
1524-string-matching-in-an-array
1537-maximum-score-after-splitting-a-string
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1667-find-kth-bit-in-nth-binary-string
1715-split-a-string-into-the-max-number-of-unique-substrings
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1915-check-if-one-string-swap-can-make-strings-equal
2021-remove-all-occurrences-of-a-substring
2292-counting-words-with-a-given-prefix
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2691-count-vowel-strings-in-ranges
3309-count-prefix-and-suffix-pairs-i
3412-permutation-difference-between-two-strings
3451-string-compression-iii
3753-maximum-difference-between-even-and-odd-frequency-i

Sliding Window

0003-longest-substring-without-repeating-characters
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
2463-minimum-recolors-to-get-k-consecutive-black-blocks

Array

0014-longest-common-prefix
0026-remove-duplicates-from-sorted-array
0027-remove-element
0036-valid-sudoku
0039-combination-sum
0054-spiral-matrix
0074-search-a-2d-matrix
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0121-best-time-to-buy-and-sell-stock
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0228-summary-ranges
0287-find-the-duplicate-number
0303-range-sum-query-immutable
0435-non-overlapping-intervals
0485-max-consecutive-ones
0496-next-greater-element-i
0503-next-greater-element-ii
0525-contiguous-array
0739-daily-temperatures
0822-unique-morse-code-words
0840-magic-squares-in-grid
0952-word-subsets
1018-largest-perimeter-triangle
1350-remove-sub-folders-from-the-filesystem
1478-maximum-number-of-events-that-can-be-attended
1524-string-matching-in-an-array
1570-final-prices-with-a-special-discount-in-a-shop
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1878-check-if-array-is-sorted-and-rotated
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1927-maximum-ascending-subarray-sum
1995-finding-pairs-with-a-certain-sum
2073-time-needed-to-buy-tickets
2277-count-equal-and-divisible-pairs-in-an-array
2292-counting-words-with-a-given-prefix
2308-divide-array-into-equal-pairs
2356-largest-combination-with-bitwise-and-greater-than-zero
2358-number-of-ways-to-split-array
2442-number-of-arithmetic-triplets
2503-longest-subarray-with-maximum-bitwise-and
2551-apply-operations-to-an-array
2586-longest-square-streak-in-an-array
2624-difference-between-element-sum-and-digit-sum-of-an-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
2691-count-vowel-strings-in-ranges
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
3074-apple-redistribution-into-boxes
3291-find-if-array-can-be-sorted
3309-count-prefix-and-suffix-pairs-i
3331-minimum-operations-to-exceed-threshold-value-i
3429-special-array-i
3446-find-the-number-of-good-pairs-i
3790-fruits-into-baskets-ii

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
0061-rotate-list
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0141-linked-list-cycle
0202-happy-number
0287-find-the-duplicate-number
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2236-maximum-twin-sum-of-a-linked-list
2442-number-of-arithmetic-triplets
2551-apply-operations-to-an-array
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values

Enumeration

2442-number-of-arithmetic-triplets

Binary Search

0074-search-a-2d-matrix
0209-minimum-size-subarray-sum
0222-count-complete-tree-nodes
0287-find-the-duplicate-number
0374-guess-number-higher-or-lower
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2586-longest-square-streak-in-an-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
2699-count-the-number-of-fair-pairs
3790-fruits-into-baskets-ii

Matrix

0036-valid-sudoku
0054-spiral-matrix
0074-search-a-2d-matrix
0840-magic-squares-in-grid

Recursion

0206-reverse-linked-list
1197-parsing-a-boolean-expression
1667-find-kth-bit-in-nth-binary-string

Simulation

0054-spiral-matrix
1667-find-kth-bit-in-nth-binary-string
2021-remove-all-occurrences-of-a-substring
2073-time-needed-to-buy-tickets
2288-count-operations-to-obtain-zero
2551-apply-operations-to-an-array
3790-fruits-into-baskets-ii

Stack

0071-simplify-path
0496-next-greater-element-i
0503-next-greater-element-ii
0739-daily-temperatures
1197-parsing-a-boolean-expression
1570-final-prices-with-a-special-discount-in-a-shop
2021-remove-all-occurrences-of-a-substring
2236-maximum-twin-sum-of-a-linked-list

Backtracking

0039-combination-sum
0113-path-sum-ii
1715-split-a-string-into-the-max-number-of-unique-substrings

Linked List

0019-remove-nth-node-from-end-of-list
0061-rotate-list
0092-reverse-linked-list-ii
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0146-lru-cache
0206-reverse-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer
2236-maximum-twin-sum-of-a-linked-list

Bit Manipulation

0222-count-complete-tree-nodes
0287-find-the-duplicate-number
2308-divide-array-into-equal-pairs
2356-largest-combination-with-bitwise-and-greater-than-zero
2503-longest-subarray-with-maximum-bitwise-and
3291-find-if-array-can-be-sorted

Dynamic Programming

0121-best-time-to-buy-and-sell-stock
0435-non-overlapping-intervals
1474-longest-zigzag-path-in-a-binary-tree
2586-longest-square-streak-in-an-array

Sorting

0088-merge-sorted-array
0435-non-overlapping-intervals
1018-largest-perimeter-triangle
1478-maximum-number-of-events-that-can-be-attended
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2586-longest-square-streak-in-an-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
2699-count-the-number-of-fair-pairs
3074-apple-redistribution-into-boxes
3291-find-if-array-can-be-sorted

Design

0146-lru-cache
0303-range-sum-query-immutable
1995-finding-pairs-with-a-certain-sum

Doubly-Linked List

0146-lru-cache

Counting

1341-split-a-string-in-balanced-strings
1915-check-if-one-string-swap-can-make-strings-equal
2308-divide-array-into-equal-pairs
2356-largest-combination-with-bitwise-and-greater-than-zero
3753-maximum-difference-between-even-and-odd-frequency-i

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
1524-string-matching-in-an-array
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i

Tree

0112-path-sum
0113-path-sum-ii
0222-count-complete-tree-nodes
0437-path-sum-iii
0450-delete-node-in-a-bst
0515-find-largest-value-in-each-tree-row
0904-leaf-similar-trees
1474-longest-zigzag-path-in-a-binary-tree
1544-count-good-nodes-in-binary-tree

Depth-First Search

0112-path-sum
0113-path-sum-ii
0133-clone-graph
0386-lexicographical-numbers
0437-path-sum-iii
0515-find-largest-value-in-each-tree-row
0904-leaf-similar-trees
1350-remove-sub-folders-from-the-filesystem
1474-longest-zigzag-path-in-a-binary-tree
1544-count-good-nodes-in-binary-tree

Binary Tree

0112-path-sum
0113-path-sum-ii
0222-count-complete-tree-nodes
0437-path-sum-iii
0450-delete-node-in-a-bst
0515-find-largest-value-in-each-tree-row
0904-leaf-similar-trees
1474-longest-zigzag-path-in-a-binary-tree
1544-count-good-nodes-in-binary-tree

Breadth-First Search

0112-path-sum
0133-clone-graph
0515-find-largest-value-in-each-tree-row
1544-count-good-nodes-in-binary-tree

Greedy

0435-non-overlapping-intervals
1018-largest-perimeter-triangle
1341-split-a-string-in-balanced-strings
1478-maximum-number-of-events-that-can-be-attended
2640-maximum-number-of-integers-to-choose-from-a-range-i
3074-apple-redistribution-into-boxes

Monotonic Stack

0496-next-greater-element-i
0503-next-greater-element-ii
0739-daily-temperatures
1570-final-prices-with-a-special-discount-in-a-shop

Binary Search Tree

0450-delete-node-in-a-bst

Math

0202-happy-number
0840-magic-squares-in-grid
1018-largest-perimeter-triangle
1411-convert-binary-number-in-a-linked-list-to-integer
1500-count-largest-group
2288-count-operations-to-obtain-zero
2624-difference-between-element-sum-and-digit-sum-of-an-array

Prefix Sum

0209-minimum-size-subarray-sum
0303-range-sum-query-immutable
0525-contiguous-array
1537-maximum-score-after-splitting-a-string
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
2358-number-of-ways-to-split-array
2691-count-vowel-strings-in-ranges

Trie

0014-longest-common-prefix
0386-lexicographical-numbers
1350-remove-sub-folders-from-the-filesystem
3309-count-prefix-and-suffix-pairs-i

Rolling Hash

3309-count-prefix-and-suffix-pairs-i

Hash Function

3309-count-prefix-and-suffix-pairs-i

Interactive

0374-guess-number-higher-or-lower

Database

0180-consecutive-numbers
0185-department-top-three-salaries
0196-delete-duplicate-emails
0570-managers-with-at-least-5-direct-reports
0596-classes-more-than-5-students
0610-triangle-judgement
0619-biggest-single-number
1135-customers-who-bought-all-products
1161-project-employees-i
1182-game-play-analysis-iv
1278-product-price-at-a-given-date
1292-immediate-food-delivery-ii
1317-monthly-transactions-i
1327-last-person-to-fit-in-the-bus
1338-queries-quality-and-percentage
1390-average-selling-price
1452-restaurant-growth
1462-list-the-products-ordered-in-a-period
1480-movie-rating
1625-group-sold-products-by-the-date
1670-patients-with-a-condition
1773-percentage-of-users-attended-a-contest
1882-the-number-of-employees-which-report-to-each-employee
1942-primary-department-for-each-employee
2057-count-salary-categories
2087-confirmation-rate
2127-employees-whose-manager-left-the-company
2495-number-of-unique-subjects-taught-by-each-teacher

Graph

0133-clone-graph

Heap (Priority Queue)

1478-maximum-number-of-events-that-can-be-attended

Brainteaser

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

Segment Tree

3790-fruits-into-baskets-ii

Ordered Set

3790-fruits-into-baskets-ii

Queue

2073-time-needed-to-buy-tickets