Leetcode

LeetCode Topics

Array

0001-two-sum
0015-3sum
0026-remove-duplicates-from-sorted-array
0033-search-in-rotated-sorted-array
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0042-trapping-rain-water
0046-permutations
0048-rotate-image
0051-n-queens
0053-maximum-subarray
0056-merge-intervals
0064-minimum-path-sum
0074-search-a-2d-matrix
0078-subsets
0088-merge-sorted-array
0090-subsets-ii
0118-pascals-triangle
0120-triangle
0121-best-time-to-buy-and-sell-stock
0123-best-time-to-buy-and-sell-stock-iii
0130-surrounded-regions
0169-majority-element
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0322-coin-change
0416-partition-equal-subset-sum
0455-assign-cookies
0485-max-consecutive-ones
0494-target-sum
0525-contiguous-array
0540-single-element-in-a-sorted-array
0542-01-matrix
0733-flood-fill
0940-fruit-into-baskets
0966-binary-subarrays-with-sum
1034-subarrays-with-k-different-integers
1036-rotting-oranges
1046-max-consecutive-ones-iii
1050-construct-binary-search-tree-from-preorder-traversal
1196-filling-bookcase-shelves
1370-count-number-of-nice-subarrays
1755-defuse-the-bomb
1983-maximum-population-year

Divide and Conquer

0053-maximum-subarray
0169-majority-element

Dynamic Programming

0005-longest-palindromic-substring
0042-trapping-rain-water
0053-maximum-subarray
0062-unique-paths
0064-minimum-path-sum
0070-climbing-stairs
0118-pascals-triangle
0120-triangle
0121-best-time-to-buy-and-sell-stock
0123-best-time-to-buy-and-sell-stock-iii
0124-binary-tree-maximum-path-sum
0131-palindrome-partitioning
0300-longest-increasing-subsequence
0322-coin-change
0416-partition-equal-subset-sum
0494-target-sum
0542-01-matrix
1013-fibonacci-number
1170-shortest-common-supersequence
1196-filling-bookcase-shelves
1250-longest-common-subsequence
1437-minimum-insertion-steps-to-make-a-string-palindrome

Math

0002-add-two-numbers
0013-roman-to-integer
0048-rotate-image
0050-powx-n
0060-permutation-sequence
0062-unique-paths
0070-climbing-stairs
1013-fibonacci-number
1370-count-number-of-nice-subarrays

Matrix

0037-sudoku-solver
0048-rotate-image
0064-minimum-path-sum
0074-search-a-2d-matrix
0130-surrounded-regions
0542-01-matrix
0733-flood-fill
1036-rotting-oranges

Sorting

0015-3sum
0056-merge-intervals
0088-merge-sorted-array
0169-majority-element
0455-assign-cookies

Two Pointers

0005-longest-palindromic-substring
0015-3sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0042-trapping-rain-water
0061-rotate-list
0088-merge-sorted-array
0141-linked-list-cycle
0142-linked-list-cycle-ii
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0234-palindrome-linked-list
0287-find-the-duplicate-number
0455-assign-cookies
0908-middle-of-the-linked-list

Binary Search

0033-search-in-rotated-sorted-array
0074-search-a-2d-matrix
0222-count-complete-tree-nodes
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0540-single-element-in-a-sorted-array
1046-max-consecutive-ones-iii

Bit Manipulation

0078-subsets
0090-subsets-ii
0222-count-complete-tree-nodes
0287-find-the-duplicate-number

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0061-rotate-list
0116-populating-next-right-pointers-in-each-node
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0908-middle-of-the-linked-list

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0050-powx-n
0060-permutation-sequence
0206-reverse-linked-list
0234-palindrome-linked-list
1013-fibonacci-number

Hash Table

0001-two-sum
0013-roman-to-integer
0037-sudoku-solver
0127-word-ladder
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0169-majority-element
0424-longest-repeating-character-replacement
0525-contiguous-array
0893-all-nodes-distance-k-in-binary-tree
0940-fruit-into-baskets
0966-binary-subarrays-with-sum
1034-subarrays-with-k-different-integers
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters

Counting

0169-majority-element
1034-subarrays-with-k-different-integers
1983-maximum-population-year

Stack

0042-trapping-rain-water
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0234-palindrome-linked-list
1050-construct-binary-search-tree-from-preorder-traversal

Sliding Window

0424-longest-repeating-character-replacement
0940-fruit-into-baskets
0966-binary-subarrays-with-sum
1034-subarrays-with-k-different-integers
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1755-defuse-the-bomb

Greedy

0455-assign-cookies

Monotonic Stack

0042-trapping-rain-water
1050-construct-binary-search-tree-from-preorder-traversal

Memoization

0070-climbing-stairs
1013-fibonacci-number

Combinatorics

0062-unique-paths

Backtracking

0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0051-n-queens
0078-subsets
0090-subsets-ii
0131-palindrome-partitioning
0494-target-sum

Prefix Sum

0525-contiguous-array
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1983-maximum-population-year

String

0005-longest-palindromic-substring
0008-string-to-integer-atoi
0013-roman-to-integer
0014-longest-common-prefix
0127-word-ladder
0131-palindrome-partitioning
0151-reverse-words-in-a-string
0424-longest-repeating-character-replacement
1170-shortest-common-supersequence
1250-longest-common-subsequence
1437-minimum-insertion-steps-to-make-a-string-palindrome
1460-number-of-substrings-containing-all-three-characters

Trie

0014-longest-common-prefix

Tree

0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0116-populating-next-right-pointers-in-each-node
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0543-diameter-of-binary-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0893-all-nodes-distance-k-in-binary-tree
1050-construct-binary-search-tree-from-preorder-traversal

Depth-First Search

0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0116-populating-next-right-pointers-in-each-node
0124-binary-tree-maximum-path-sum
0130-surrounded-regions
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0207-course-schedule
0210-course-schedule-ii
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0543-diameter-of-binary-tree
0733-flood-fill
0801-is-graph-bipartite
0893-all-nodes-distance-k-in-binary-tree

Binary Tree

0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0116-populating-next-right-pointers-in-each-node
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0543-diameter-of-binary-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0893-all-nodes-distance-k-in-binary-tree
1050-construct-binary-search-tree-from-preorder-traversal

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0116-populating-next-right-pointers-in-each-node
0127-word-ladder
0130-surrounded-regions
0199-binary-tree-right-side-view
0207-course-schedule
0210-course-schedule-ii
0322-coin-change
0542-01-matrix
0733-flood-fill
0801-is-graph-bipartite
0893-all-nodes-distance-k-in-binary-tree
1036-rotting-oranges

Binary Search Tree

0098-validate-binary-search-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
1050-construct-binary-search-tree-from-preorder-traversal

Union Find

0130-surrounded-regions
0801-is-graph-bipartite

Graph

0207-course-schedule
0210-course-schedule-ii
0801-is-graph-bipartite

Topological Sort

0207-course-schedule
0210-course-schedule-ii