Leetcode

Leetcode solutions

Two Pointers

0026-remove-duplicates-from-sorted-array
0075-sort-colors
0189-rotate-array
0283-move-zeroes
0344-reverse-string
0633-sum-of-square-numbers
0853-most-profit-assigning-work
2572-append-characters-to-string-to-make-subsequence

String

0344-reverse-string
0409-longest-palindrome
0648-replace-words
1044-find-common-characters
2572-append-characters-to-string-to-make-subsequence

Array

0026-remove-duplicates-from-sorted-array
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0053-maximum-subarray
0075-sort-colors
0081-search-in-rotated-sorted-array-ii
0121-best-time-to-buy-and-sell-stock
0136-single-number
0153-find-minimum-in-rotated-sorted-array
0169-majority-element
0189-rotate-array
0229-majority-element-ii
0283-move-zeroes
0330-patching-array
0485-max-consecutive-ones
0502-ipo
0523-continuous-subarray-sum
0648-replace-words
0853-most-profit-assigning-work
0876-hand-of-straights
0982-minimum-increment-to-make-array-unique
1016-subarray-sums-divisible-by-k
1037-minimum-number-of-k-consecutive-bit-flips
1044-find-common-characters
1137-height-checker
1138-grumpy-bookstore-owner
1217-relative-sort-array
1370-count-number-of-nice-subarrays
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1605-minimum-number-of-days-to-make-m-bouquets
1675-magnetic-force-between-two-balls
1878-check-if-array-is-sorted-and-rotated
2148-minimum-number-of-moves-to-seat-everyone

Binary Search

0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0081-search-in-rotated-sorted-array-ii
0153-find-minimum-in-rotated-sorted-array
0633-sum-of-square-numbers
0853-most-profit-assigning-work
1605-minimum-number-of-days-to-make-m-bouquets
1675-magnetic-force-between-two-balls

Greedy

0330-patching-array
0409-longest-palindrome
0502-ipo
0853-most-profit-assigning-work
0876-hand-of-straights
0982-minimum-increment-to-make-array-unique
1285-balance-a-binary-search-tree
2148-minimum-number-of-moves-to-seat-everyone
2572-append-characters-to-string-to-make-subsequence

Math

0009-palindrome-number
0189-rotate-array
0523-continuous-subarray-sum
0633-sum-of-square-numbers
1370-count-number-of-nice-subarrays

Hash Table

0169-majority-element
0229-majority-element-ii
0409-longest-palindrome
0523-continuous-subarray-sum
0648-replace-words
0876-hand-of-straights
1016-subarray-sums-divisible-by-k
1044-find-common-characters
1217-relative-sort-array
1370-count-number-of-nice-subarrays

Sorting

0075-sort-colors
0169-majority-element
0229-majority-element-ii
0502-ipo
0853-most-profit-assigning-work
0876-hand-of-straights
0982-minimum-increment-to-make-array-unique
1137-height-checker
1217-relative-sort-array
1675-magnetic-force-between-two-balls
2148-minimum-number-of-moves-to-seat-everyone

Trie

0648-replace-words

Bit Manipulation

0136-single-number
1037-minimum-number-of-k-consecutive-bit-flips

Prefix Sum

0523-continuous-subarray-sum
1016-subarray-sums-divisible-by-k
1037-minimum-number-of-k-consecutive-bit-flips

Counting Sort

0169-majority-element
0229-majority-element-ii
0982-minimum-increment-to-make-array-unique
1137-height-checker
1217-relative-sort-array

Dynamic Programming

0053-maximum-subarray
0121-best-time-to-buy-and-sell-stock

Divide and Conquer

0053-maximum-subarray
0169-majority-element
1285-balance-a-binary-search-tree

Heap (Priority Queue)

0502-ipo
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Sliding Window

1037-minimum-number-of-k-consecutive-bit-flips
1138-grumpy-bookstore-owner
1370-count-number-of-nice-subarrays
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Queue

1037-minimum-number-of-k-consecutive-bit-flips
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Ordered Set

1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Monotonic Queue

1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Tree

1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Depth-First Search

1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Binary Search Tree

1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Binary Tree

1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Graph

1916-find-center-of-star-graph

LeetCode Topics

Greedy

0179-largest-number
0670-maximum-swap
0957-minimum-add-to-make-parentheses-valid
1341-split-a-string-in-balanced-strings
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1766-minimum-number-of-removals-to-make-mountain-array
1818-maximum-score-from-removing-substrings
2379-maximum-total-importance-of-roads
2488-divide-intervals-into-minimum-number-of-groups
3195-separate-black-and-white-balls

Graph

1325-path-with-maximum-probability
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1701-remove-max-number-of-edges-to-keep-graph-fully-traversable
2379-maximum-total-importance-of-roads
2803-modify-graph-edge-weights

Sorting

0075-sort-colors
0179-largest-number
0268-missing-number
0350-intersection-of-two-arrays-ii
0389-find-the-difference
0539-minimum-time-difference
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
2379-maximum-total-importance-of-roads
2488-divide-intervals-into-minimum-number-of-groups
2846-robot-collisions
3291-find-if-array-can-be-sorted

Heap (Priority Queue)

1325-path-with-maximum-probability
2379-maximum-total-importance-of-roads
2488-divide-intervals-into-minimum-number-of-groups
2803-modify-graph-edge-weights

Depth-First Search

0124-binary-tree-maximum-path-sum
0145-binary-tree-postorder-traversal
0386-lexicographical-numbers
0776-n-ary-tree-postorder-traversal
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1484-linked-list-in-binary-tree

Breadth-First Search

1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1484-linked-list-in-binary-tree

Topological Sort

1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph

Array

0026-remove-duplicates-from-sorted-array
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0051-n-queens
0054-spiral-matrix
0063-unique-paths-ii
0064-minimum-path-sum
0075-sort-colors
0078-subsets
0090-subsets-ii
0120-triangle
0136-single-number
0162-find-peak-element
0179-largest-number
0189-rotate-array
0198-house-robber
0213-house-robber-ii
0268-missing-number
0283-move-zeroes
0287-find-the-duplicate-number
0350-intersection-of-two-arrays-ii
0416-partition-equal-subset-sum
0496-next-greater-element-i
0539-minimum-time-difference
0729-my-calendar-i
0731-my-calendar-ii
0739-daily-temperatures
0859-design-circular-deque
0906-walking-robot-simulation
1044-find-common-characters
1196-filling-bookcase-shelves
1293-three-consecutive-odds
1325-path-with-maximum-probability
1435-xor-queries-of-a-subarray
1497-design-a-stack-with-increment-operation
1511-count-number-of-teams
1605-minimum-number-of-days-to-make-m-bouquets
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1620-check-if-array-pairs-are-divisible-by-k
1720-crawler-log-folder
1766-minimum-number-of-removals-to-make-mountain-array
1786-count-the-number-of-consistent-strings
1803-average-waiting-time
1878-check-if-array-is-sorted-and-rotated
1951-find-the-winner-of-the-circular-game
2006-find-the-student-that-will-replace-the-chalk
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2232-adding-spaces-to-a-string
2411-spiral-matrix-iv
2488-divide-intervals-into-minimum-number-of-groups
2494-sum-of-prefix-scores-of-strings
2503-longest-subarray-with-maximum-bitwise-and
2552-maximum-sum-of-distinct-subarrays-with-length-k
2755-extra-characters-in-a-string
2846-robot-collisions
3291-find-if-array-can-be-sorted
3329-find-the-length-of-the-longest-common-prefix
3501-delete-nodes-from-linked-list-present-in-array

Binary Search

0162-find-peak-element
0268-missing-number
0287-find-the-duplicate-number
0350-intersection-of-two-arrays-ii
0729-my-calendar-i
0731-my-calendar-ii
1605-minimum-number-of-days-to-make-m-bouquets
1766-minimum-number-of-removals-to-make-mountain-array
2006-find-the-student-that-will-replace-the-chalk

Union Find

1701-remove-max-number-of-edges-to-keep-graph-fully-traversable

Hash Table

0037-sudoku-solver
0268-missing-number
0350-intersection-of-two-arrays-ii
0389-find-the-difference
0432-all-oone-data-structure
0496-next-greater-element-i
0567-permutation-in-string
0906-walking-robot-simulation
0920-uncommon-words-from-two-sentences
1044-find-common-characters
1473-find-the-longest-substring-containing-vowels-in-even-counts
1620-check-if-array-pairs-are-divisible-by-k
1715-split-a-string-into-the-max-number-of-unique-substrings
1786-count-the-number-of-consistent-strings
2552-maximum-sum-of-distinct-subarrays-with-length-k
2755-extra-characters-in-a-string
3329-find-the-length-of-the-longest-common-prefix
3501-delete-nodes-from-linked-list-present-in-array

String

0020-valid-parentheses
0022-generate-parentheses
0125-valid-palindrome
0131-palindrome-partitioning
0179-largest-number
0214-shortest-palindrome
0241-different-ways-to-add-parentheses
0344-reverse-string
0389-find-the-difference
0539-minimum-time-difference
0567-permutation-in-string
0592-fraction-addition-and-subtraction
0874-backspace-string-compare
0920-uncommon-words-from-two-sentences
0957-minimum-add-to-make-parentheses-valid
1044-find-common-characters
1298-reverse-substrings-between-each-pair-of-parentheses
1302-delete-characters-to-make-fancy-string
1341-split-a-string-in-balanced-strings
1473-find-the-longest-substring-containing-vowels-in-even-counts
1715-split-a-string-into-the-max-number-of-unique-substrings
1720-crawler-log-folder
1756-minimum-deletions-to-make-string-balanced
1786-count-the-number-of-consistent-strings
1818-maximum-score-from-removing-substrings
2076-sum-of-digits-of-string-after-convert
2232-adding-spaces-to-a-string
2494-sum-of-prefix-scores-of-strings
2580-circular-sentence
2755-extra-characters-in-a-string
2800-minimum-string-length-after-removing-substrings
3018-make-string-a-subsequence-using-cyclic-increments
3174-minimum-number-of-changes-to-make-binary-string-beautiful
3195-separate-black-and-white-balls
3329-find-the-length-of-the-longest-common-prefix

Bit Manipulation

0078-subsets
0090-subsets-ii
0136-single-number
0268-missing-number
0287-find-the-duplicate-number
0389-find-the-difference
0476-number-complement
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1786-count-the-number-of-consistent-strings
2323-minimum-bit-flips-to-convert-number
2503-longest-subarray-with-maximum-bitwise-and
3291-find-if-array-can-be-sorted
3394-minimum-array-end

Two Pointers

0026-remove-duplicates-from-sorted-array
0075-sort-colors
0125-valid-palindrome
0189-rotate-array
0283-move-zeroes
0287-find-the-duplicate-number
0344-reverse-string
0350-intersection-of-two-arrays-ii
0567-permutation-in-string
0874-backspace-string-compare
2232-adding-spaces-to-a-string
2488-divide-intervals-into-minimum-number-of-groups
3018-make-string-a-subsequence-using-cyclic-increments
3195-separate-black-and-white-balls

Linked List

0002-add-two-numbers
0328-odd-even-linked-list
0432-all-oone-data-structure
0725-split-linked-list-in-parts
0859-design-circular-deque
1484-linked-list-in-binary-tree
2182-find-the-minimum-and-maximum-number-of-nodes-between-critical-points
2299-merge-nodes-in-between-zeros
2411-spiral-matrix-iv
2903-insert-greatest-common-divisors-in-linked-list
3501-delete-nodes-from-linked-list-present-in-array

Simulation

0054-spiral-matrix
0592-fraction-addition-and-subtraction
0874-backspace-string-compare
0906-walking-robot-simulation
1642-water-bottles
1803-average-waiting-time
1951-find-the-winner-of-the-circular-game
2006-find-the-student-that-will-replace-the-chalk
2076-sum-of-digits-of-string-after-convert
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2232-adding-spaces-to-a-string
2299-merge-nodes-in-between-zeros
2411-spiral-matrix-iv
2645-pass-the-pillow
2800-minimum-string-length-after-removing-substrings
2846-robot-collisions

Math

0002-add-two-numbers
0062-unique-paths
0070-climbing-stairs
0189-rotate-array
0241-different-ways-to-add-parentheses
0268-missing-number
0539-minimum-time-difference
0592-fraction-addition-and-subtraction
0670-maximum-swap
1642-water-bottles
1951-find-the-winner-of-the-circular-game
2155-find-missing-observations
2645-pass-the-pillow
2903-insert-greatest-common-divisors-in-linked-list

Recursion

0002-add-two-numbers
0241-different-ways-to-add-parentheses
1951-find-the-winner-of-the-circular-game

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0859-design-circular-deque
1951-find-the-winner-of-the-circular-game

Stack

0020-valid-parentheses
0145-binary-tree-postorder-traversal
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0496-next-greater-element-i
0739-daily-temperatures
0776-n-ary-tree-postorder-traversal
0874-backspace-string-compare
0937-online-stock-span
0957-minimum-add-to-make-parentheses-valid
1298-reverse-substrings-between-each-pair-of-parentheses
1497-design-a-stack-with-increment-operation
1720-crawler-log-folder
1756-minimum-deletions-to-make-string-balanced
1818-maximum-score-from-removing-substrings
2800-minimum-string-length-after-removing-substrings
2846-robot-collisions

Dynamic Programming

0022-generate-parentheses
0062-unique-paths
0063-unique-paths-ii
0064-minimum-path-sum
0070-climbing-stairs
0120-triangle
0124-binary-tree-maximum-path-sum
0131-palindrome-partitioning
0198-house-robber
0213-house-robber-ii
0241-different-ways-to-add-parentheses
0416-partition-equal-subset-sum
1196-filling-bookcase-shelves
1511-count-number-of-teams
1756-minimum-deletions-to-make-string-balanced
1766-minimum-number-of-removals-to-make-mountain-array
2755-extra-characters-in-a-string

Binary Indexed Tree

1511-count-number-of-teams

Tree

0124-binary-tree-maximum-path-sum
0145-binary-tree-postorder-traversal
0776-n-ary-tree-postorder-traversal
1484-linked-list-in-binary-tree

Binary Tree

0124-binary-tree-maximum-path-sum
0145-binary-tree-postorder-traversal
1484-linked-list-in-binary-tree

Shortest Path

1325-path-with-maximum-probability
2803-modify-graph-edge-weights

Matrix

0037-sudoku-solver
0054-spiral-matrix
0063-unique-paths-ii
0064-minimum-path-sum
2132-convert-1d-array-into-2d-array
2411-spiral-matrix-iv

Prefix Sum

0731-my-calendar-ii
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
2006-find-the-student-that-will-replace-the-chalk
2488-divide-intervals-into-minimum-number-of-groups

Number Theory

2903-insert-greatest-common-divisors-in-linked-list

Counting

0920-uncommon-words-from-two-sentences
1341-split-a-string-in-balanced-strings
1620-check-if-array-pairs-are-divisible-by-k
1786-count-the-number-of-consistent-strings
2494-sum-of-prefix-scores-of-strings

Brainteaser

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

Memoization

0070-climbing-stairs
0241-different-ways-to-add-parentheses

Rolling Hash

0214-shortest-palindrome

String Matching

0214-shortest-palindrome

Hash Function

0214-shortest-palindrome

Trie

0386-lexicographical-numbers
0440-k-th-smallest-in-lexicographical-order
2494-sum-of-prefix-scores-of-strings
2755-extra-characters-in-a-string
3329-find-the-length-of-the-longest-common-prefix

Design

0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0432-all-oone-data-structure
0729-my-calendar-i
0731-my-calendar-ii
0859-design-circular-deque
0937-online-stock-span
1497-design-a-stack-with-increment-operation

Monotonic Stack

0496-next-greater-element-i
0739-daily-temperatures
0937-online-stock-span

Data Stream

0937-online-stock-span

Segment Tree

0729-my-calendar-i
0731-my-calendar-ii

Ordered Set

0729-my-calendar-i
0731-my-calendar-ii

Doubly-Linked List

0432-all-oone-data-structure

Sliding Window

0567-permutation-in-string
2552-maximum-sum-of-distinct-subarrays-with-length-k

Backtracking

0022-generate-parentheses
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0051-n-queens
0078-subsets
0090-subsets-ii
0131-palindrome-partitioning
1715-split-a-string-into-the-max-number-of-unique-substrings

Combinatorics

0062-unique-paths