leetcode

LeetCode Topics

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0033-search-in-rotated-sorted-array
0035-search-insert-position
0036-valid-sudoku
0042-trapping-rain-water
0049-group-anagrams
0054-spiral-matrix
0066-plus-one
0074-search-a-2d-matrix
0088-merge-sorted-array
0118-pascals-triangle
0119-pascals-triangle-ii
0128-longest-consecutive-sequence
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0238-product-of-array-except-self
0283-move-zeroes
0334-increasing-triplet-subsequence
0347-top-k-frequent-elements
0414-third-maximum-number
0448-find-all-numbers-disappeared-in-an-array
0485-max-consecutive-ones
0498-diagonal-traverse
0605-can-place-flowers
0643-maximum-average-subarray-i
0724-find-pivot-index
0748-largest-number-at-least-twice-of-others
0792-binary-search
0907-koko-eating-bananas
0941-sort-array-by-parity
0978-valid-mountain-array
1019-squares-of-a-sorted-array
1046-max-consecutive-ones-iii
1137-height-checker
1168-duplicate-zeros
1231-replace-elements-with-greatest-element-on-right-side
1319-unique-number-of-occurrences
1392-find-the-difference-of-two-arrays
1421-find-numbers-with-even-number-of-digits
1468-check-if-n-and-its-double-exist
1528-kids-with-the-greatest-number-of-candies
1586-longest-subarray-of-1s-after-deleting-one-element
1791-richest-customer-wealth
1798-max-number-of-k-sum-pairs
1833-find-the-highest-altitude

Hash Table

0001-two-sum
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
0160-intersection-of-two-linked-lists
0347-top-k-frequent-elements
0383-ransom-note
0448-find-all-numbers-disappeared-in-an-array
1023-time-based-key-value-store
1319-unique-number-of-occurrences
1392-find-the-difference-of-two-arrays
1468-check-if-n-and-its-double-exist
1777-determine-if-two-strings-are-close
1798-max-number-of-k-sum-pairs

Two Pointers

0011-container-with-most-water
0015-3sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0027-remove-element
0042-trapping-rain-water
0061-rotate-list
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0167-two-sum-ii-input-array-is-sorted
0234-palindrome-linked-list
0283-move-zeroes
0344-reverse-string
0345-reverse-vowels-of-a-string
0392-is-subsequence
0443-string-compression
0908-middle-of-the-linked-list
0941-sort-array-by-parity
1019-squares-of-a-sorted-array
1168-duplicate-zeros
1468-check-if-n-and-its-double-exist
1798-max-number-of-k-sum-pairs
1894-merge-strings-alternately

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0035-search-insert-position
0074-search-a-2d-matrix
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0792-binary-search
0907-koko-eating-bananas
1023-time-based-key-value-store
1046-max-consecutive-ones-iii
1468-check-if-n-and-its-double-exist

Math

0002-add-two-numbers
0066-plus-one
0070-climbing-stairs
0412-fizz-buzz
1013-fibonacci-number
1146-greatest-common-divisor-of-strings
1421-find-numbers-with-even-number-of-digits
1444-number-of-steps-to-reduce-a-number-to-zero

String

0049-group-anagrams
0125-valid-palindrome
0151-reverse-words-in-a-string
0344-reverse-string
0345-reverse-vowels-of-a-string
0383-ransom-note
0392-is-subsequence
0412-fizz-buzz
0443-string-compression
0606-construct-string-from-binary-tree
1023-time-based-key-value-store
1146-greatest-common-divisor-of-strings
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1777-determine-if-two-strings-are-close
1894-merge-strings-alternately

Greedy

0011-container-with-most-water
0334-increasing-triplet-subsequence
0605-can-place-flowers

Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0112-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0226-invert-binary-tree
0606-construct-string-from-binary-tree
0783-search-in-a-binary-search-tree

Depth-First Search

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0112-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0226-invert-binary-tree
0606-construct-string-from-binary-tree
0766-flatten-a-multilevel-doubly-linked-list

Binary Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0112-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0226-invert-binary-tree
0606-construct-string-from-binary-tree
0783-search-in-a-binary-search-tree

Prefix Sum

0238-product-of-array-except-self
0724-find-pivot-index
1046-max-consecutive-ones-iii
1833-find-the-highest-altitude

Dynamic Programming

0042-trapping-rain-water
0070-climbing-stairs
0118-pascals-triangle
0119-pascals-triangle-ii
0392-is-subsequence
1013-fibonacci-number
1586-longest-subarray-of-1s-after-deleting-one-element

Sorting

0015-3sum
0049-group-anagrams
0088-merge-sorted-array
0347-top-k-frequent-elements
0414-third-maximum-number
0748-largest-number-at-least-twice-of-others
0941-sort-array-by-parity
1019-squares-of-a-sorted-array
1137-height-checker
1468-check-if-n-and-its-double-exist
1777-determine-if-two-strings-are-close
1798-max-number-of-k-sum-pairs

Sliding Window

0643-maximum-average-subarray-i
1046-max-consecutive-ones-iii
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1586-longest-subarray-of-1s-after-deleting-one-element

Counting

0347-top-k-frequent-elements
0383-ransom-note
1777-determine-if-two-strings-are-close

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0061-rotate-list
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0203-remove-linked-list-elements
0206-reverse-linked-list
0234-palindrome-linked-list
0328-odd-even-linked-list
0766-flatten-a-multilevel-doubly-linked-list
0838-design-linked-list
0908-middle-of-the-linked-list

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0203-remove-linked-list-elements
0206-reverse-linked-list
0234-palindrome-linked-list
1013-fibonacci-number

Matrix

0036-valid-sudoku
0054-spiral-matrix
0074-search-a-2d-matrix
0498-diagonal-traverse
1791-richest-customer-wealth

Simulation

0054-spiral-matrix
0412-fizz-buzz
0498-diagonal-traverse

Bit Manipulation

1444-number-of-steps-to-reduce-a-number-to-zero

Counting Sort

1137-height-checker

Design

0838-design-linked-list
1023-time-based-key-value-store

Stack

0042-trapping-rain-water
0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0234-palindrome-linked-list

Doubly-Linked List

0766-flatten-a-multilevel-doubly-linked-list

Divide and Conquer

0004-median-of-two-sorted-arrays
0347-top-k-frequent-elements

Heap (Priority Queue)

0347-top-k-frequent-elements

Bucket Sort

0347-top-k-frequent-elements

Quickselect

0347-top-k-frequent-elements

Union Find

0128-longest-consecutive-sequence

Monotonic Stack

0042-trapping-rain-water

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0112-path-sum
0226-invert-binary-tree

Binary Search Tree

0783-search-in-a-binary-search-tree

Memoization

0070-climbing-stairs
1013-fibonacci-number