Leetcode

Math

0009-palindrome-number

LeetCode Topics

Array

0001-two-sum
0011-container-with-most-water
0015-3sum
0033-search-in-rotated-sorted-array
0035-search-insert-position
0036-valid-sudoku
0049-group-anagrams
0074-search-a-2d-matrix
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
0217-contains-duplicate
0219-contains-duplicate-ii
0238-product-of-array-except-self
0268-missing-number
0283-move-zeroes
0287-find-the-duplicate-number
0347-top-k-frequent-elements
0682-baseball-game
0739-daily-temperatures
0792-binary-search
0940-fruit-into-baskets
1014-k-closest-points-to-origin
1094-matrix-cells-in-distance-order
1939-queries-on-number-of-points-inside-a-circle
2332-count-lattice-points-inside-a-circle

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0036-valid-sudoku
0049-group-anagrams
0128-longest-consecutive-sequence
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0217-contains-duplicate
0219-contains-duplicate-ii
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
0383-ransom-note
0387-first-unique-character-in-a-string
0424-longest-repeating-character-replacement
0567-permutation-in-string
0940-fruit-into-baskets
2332-count-lattice-points-inside-a-circle
2427-first-letter-to-appear-twice

Union Find

0128-longest-consecutive-sequence

Two Pointers

0011-container-with-most-water
0015-3sum
0019-remove-nth-node-from-end-of-list
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0167-two-sum-ii-input-array-is-sorted
0283-move-zeroes
0287-find-the-duplicate-number
0567-permutation-in-string
0908-middle-of-the-linked-list

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0069-sqrtx
0150-evaluate-reverse-polish-notation
0268-missing-number
1014-k-closest-points-to-origin
1094-matrix-cells-in-distance-order
1939-queries-on-number-of-points-inside-a-circle
2332-count-lattice-points-inside-a-circle

Geometry

1014-k-closest-points-to-origin
1094-matrix-cells-in-distance-order
1939-queries-on-number-of-points-inside-a-circle
2332-count-lattice-points-inside-a-circle

Sorting

0015-3sum
0049-group-anagrams
0217-contains-duplicate
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
1014-k-closest-points-to-origin
1094-matrix-cells-in-distance-order

Matrix

0036-valid-sudoku
0074-search-a-2d-matrix
1094-matrix-cells-in-distance-order

Divide and Conquer

0347-top-k-frequent-elements
1014-k-closest-points-to-origin

Heap (Priority Queue)

0347-top-k-frequent-elements
1014-k-closest-points-to-origin

Quickselect

0347-top-k-frequent-elements
1014-k-closest-points-to-origin

Enumeration

2332-count-lattice-points-inside-a-circle

Binary Search

0033-search-in-rotated-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
0268-missing-number
0287-find-the-duplicate-number
0374-guess-number-higher-or-lower
0792-binary-search

Bit Manipulation

0268-missing-number
0287-find-the-duplicate-number
2427-first-letter-to-appear-twice

String

0003-longest-substring-without-repeating-characters
0020-valid-parentheses
0022-generate-parentheses
0049-group-anagrams
0125-valid-palindrome
0242-valid-anagram
0383-ransom-note
0387-first-unique-character-in-a-string
0424-longest-repeating-character-replacement
0567-permutation-in-string
2427-first-letter-to-appear-twice

Prefix Sum

0238-product-of-array-except-self

Bucket Sort

0347-top-k-frequent-elements

Counting

0347-top-k-frequent-elements
0383-ransom-note
0387-first-unique-character-in-a-string
2427-first-letter-to-appear-twice

Greedy

0011-container-with-most-water

Dynamic Programming

0022-generate-parentheses
0121-best-time-to-buy-and-sell-stock

Sliding Window

0003-longest-substring-without-repeating-characters
0219-contains-duplicate-ii
0424-longest-repeating-character-replacement
0567-permutation-in-string
0940-fruit-into-baskets

Stack

0020-valid-parentheses
0094-binary-tree-inorder-traversal
0143-reorder-list
0144-binary-tree-preorder-traversal
0150-evaluate-reverse-polish-notation
0155-min-stack
0225-implement-stack-using-queues
0682-baseball-game
0739-daily-temperatures

Simulation

0682-baseball-game

Design

0155-min-stack
0225-implement-stack-using-queues

Queue

0225-implement-stack-using-queues
0387-first-unique-character-in-a-string

Backtracking

0022-generate-parentheses

Monotonic Stack

0739-daily-temperatures

Interactive

0374-guess-number-higher-or-lower

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0206-reverse-linked-list
0908-middle-of-the-linked-list

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0143-reorder-list
0206-reverse-linked-list

Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0144-binary-tree-preorder-traversal
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
1544-count-good-nodes-in-binary-tree

Depth-First Search

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0144-binary-tree-preorder-traversal
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
1544-count-good-nodes-in-binary-tree

Binary Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0144-binary-tree-preorder-traversal
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
1544-count-good-nodes-in-binary-tree

Breadth-First Search

0100-same-tree
0104-maximum-depth-of-binary-tree
0226-invert-binary-tree
1544-count-good-nodes-in-binary-tree

String Matching

0572-subtree-of-another-tree

Hash Function

0572-subtree-of-another-tree

Binary Search Tree

0098-validate-binary-search-tree
0235-lowest-common-ancestor-of-a-binary-search-tree