DSA

LeetCode Topics

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0025-reverse-nodes-in-k-group
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0138-copy-list-with-random-pointer
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0237-delete-node-in-a-linked-list

Math

0002-add-two-numbers
0012-integer-to-roman
0013-roman-to-integer
0048-rotate-image
0050-powx-n
0060-permutation-sequence
0062-unique-paths
0066-plus-one
0069-sqrtx
0189-rotate-array
0231-power-of-two
0326-power-of-three
0342-power-of-four
0380-insert-delete-getrandom-o1

Recursion

0002-add-two-numbers
0025-reverse-nodes-in-k-group
0050-powx-n
0060-permutation-sequence
0206-reverse-linked-list
0231-power-of-two
0326-power-of-three
0342-power-of-four

Stack

0020-valid-parentheses
0042-trapping-rain-water
0094-binary-tree-inorder-traversal
0114-flatten-binary-tree-to-linked-list
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0496-next-greater-element-i
1050-construct-binary-search-tree-from-preorder-traversal
1985-maximum-subarray-min-product

Design

0173-binary-search-tree-iterator
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0297-serialize-and-deserialize-binary-tree
0380-insert-delete-getrandom-o1

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0387-first-unique-character-in-a-string
2195-time-needed-to-buy-tickets

Array

0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0042-trapping-rain-water
0045-jump-game-ii
0046-permutations
0047-permutations-ii
0048-rotate-image
0053-maximum-subarray
0055-jump-game
0056-merge-intervals
0066-plus-one
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0134-gas-station
0135-candy
0137-single-number-ii
0169-majority-element
0189-rotate-array
0215-kth-largest-element-in-an-array
0238-product-of-array-except-self
0274-h-index
0287-find-the-duplicate-number
0380-insert-delete-getrandom-o1
0435-non-overlapping-intervals
0485-max-consecutive-ones
0496-next-greater-element-i
0792-binary-search
0898-transpose-matrix
1050-construct-binary-search-tree-from-preorder-traversal
1878-check-if-array-is-sorted-and-rotated
1985-maximum-subarray-min-product
2195-time-needed-to-buy-tickets
2270-find-all-lonely-numbers-in-the-array

Hash Table

0012-integer-to-roman
0013-roman-to-integer
0073-set-matrix-zeroes
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0138-copy-list-with-random-pointer
0160-intersection-of-two-linked-lists
0169-majority-element
0242-valid-anagram
0380-insert-delete-getrandom-o1
0387-first-unique-character-in-a-string
0496-next-greater-element-i
2186-count-vowel-substrings-of-a-string
2270-find-all-lonely-numbers-in-the-array

Monotonic Stack

0042-trapping-rain-water
0496-next-greater-element-i
1050-construct-binary-search-tree-from-preorder-traversal
1985-maximum-subarray-min-product

String

0005-longest-palindromic-substring
0012-integer-to-roman
0013-roman-to-integer
0020-valid-parentheses
0058-length-of-last-word
0125-valid-palindrome
0242-valid-anagram
0297-serialize-and-deserialize-binary-tree
0344-reverse-string
0387-first-unique-character-in-a-string
2186-count-vowel-substrings-of-a-string

Counting

0169-majority-element
0387-first-unique-character-in-a-string
2270-find-all-lonely-numbers-in-the-array

Simulation

0898-transpose-matrix
2195-time-needed-to-buy-tickets

Prefix Sum

0238-product-of-array-except-self
1985-maximum-subarray-min-product

Greedy

0045-jump-game-ii
0055-jump-game
0134-gas-station
0135-candy
0435-non-overlapping-intervals

Tree

0094-binary-tree-inorder-traversal
0099-recover-binary-search-tree
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0513-find-bottom-left-tree-value
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
0662-maximum-width-of-binary-tree
1050-construct-binary-search-tree-from-preorder-traversal
1114-binary-search-tree-to-greater-sum-tree

Depth-First Search

0094-binary-tree-inorder-traversal
0099-recover-binary-search-tree
0100-same-tree
0101-symmetric-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0513-find-bottom-left-tree-value
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
0662-maximum-width-of-binary-tree
1114-binary-search-tree-to-greater-sum-tree

Binary Tree

0094-binary-tree-inorder-traversal
0099-recover-binary-search-tree
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0513-find-bottom-left-tree-value
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
0662-maximum-width-of-binary-tree
1050-construct-binary-search-tree-from-preorder-traversal
1114-binary-search-tree-to-greater-sum-tree

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0116-populating-next-right-pointers-in-each-node
0199-binary-tree-right-side-view
0297-serialize-and-deserialize-binary-tree
0513-find-bottom-left-tree-value
0662-maximum-width-of-binary-tree

String Matching

0572-subtree-of-another-tree

Hash Function

0572-subtree-of-another-tree

Binary Search Tree

0069-sqrtx
0074-search-a-2d-matrix
0099-recover-binary-search-tree
0108-convert-sorted-array-to-binary-search-tree
0173-binary-search-tree-iterator
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0287-find-the-duplicate-number
0792-binary-search
1050-construct-binary-search-tree-from-preorder-traversal
1114-binary-search-tree-to-greater-sum-tree

Divide and Conquer

0053-maximum-subarray
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0169-majority-element
0215-kth-largest-element-in-an-array

Iterator

0173-binary-search-tree-iterator

Two Pointers

0005-longest-palindromic-substring
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0042-trapping-rain-water
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0125-valid-palindrome
0160-intersection-of-two-linked-lists
0189-rotate-array
0287-find-the-duplicate-number
0344-reverse-string

Sorting

0047-permutations-ii
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0215-kth-largest-element-in-an-array
0242-valid-anagram
0274-h-index
0435-non-overlapping-intervals

Heap (Priority Queue)

0215-kth-largest-element-in-an-array

Quickselect

0215-kth-largest-element-in-an-array

Matrix

0048-rotate-image
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0898-transpose-matrix

Dynamic Programming

0005-longest-palindromic-substring
0042-trapping-rain-water
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0062-unique-paths
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0435-non-overlapping-intervals

Bit Manipulation

0137-single-number-ii
0231-power-of-two
0287-find-the-duplicate-number
0342-power-of-four

Combinatorics

0062-unique-paths

Backtracking

0046-permutations
0047-permutations-ii

Counting Sort

0274-h-index

Randomized

0380-insert-delete-getrandom-o1