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
0033-search-in-rotated-sorted-array
0039-combination-sum
0041-first-missing-positive
0042-trapping-rain-water
0045-jump-game-ii
0048-rotate-image
0049-group-anagrams
0053-maximum-subarray
0055-jump-game
0056-merge-intervals
0063-unique-paths-ii
0066-plus-one
0073-set-matrix-zeroes
0078-subsets
0079-word-search
0081-search-in-rotated-sorted-array-ii
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0137-single-number-ii
0150-evaluate-reverse-polish-notation
0152-maximum-product-subarray
0164-maximum-gap
0169-majority-element
0189-rotate-array
0198-house-robber
0200-number-of-islands
0212-word-search-ii
0213-house-robber-ii
0217-contains-duplicate
0238-product-of-array-except-self
0268-missing-number
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0322-coin-change
0347-top-k-frequent-elements
0378-kth-smallest-element-in-a-sorted-matrix
0416-partition-equal-subset-sum
0417-pacific-atlantic-water-flow
0435-non-overlapping-intervals
0442-find-all-duplicates-in-an-array
0474-ones-and-zeroes
0494-target-sum
0518-coin-change-ii
0560-subarray-sum-equals-k
0876-hand-of-straights
0883-car-fleet
0912-random-pick-with-weight
1001-n-repeated-element-in-size-2n-array
1284-four-divisors
1395-minimum-time-visiting-all-points
1413-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1569-max-dot-product-of-two-subsequences
1631-number-of-sub-arrays-with-odd-sum
1988-minimize-maximum-pair-sum-in-array
2089-maximum-matrix-sum
2112-minimum-difference-between-highest-and-lowest-of-k-scores
2139-detect-squares
2160-minimum-operations-to-make-a-uni-value-grid
2255-minimum-swaps-to-group-all-1s-together-ii
2588-maximum-number-of-points-from-grid-queries
2888-minimum-index-of-a-valid-split
3214-maximize-area-of-square-hole-in-grid
3250-maximum-square-area-by-removing-fences-from-a-field
3325-find-the-largest-area-of-square-inside-two-rectangles
3605-construct-the-minimum-bitwise-array-i
3763-separate-squares-i
3773-minimum-pair-removal-to-sort-array-i
3775-separate-squares-ii

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0081-search-in-rotated-sorted-array-ii
0268-missing-number
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0378-kth-smallest-element-in-a-sorted-matrix
0912-random-pick-with-weight
1413-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
3763-separate-squares-i
3775-separate-squares-ii

Sorting

0015-3sum
0049-group-anagrams
0056-merge-intervals
0164-maximum-gap
0169-majority-element
0217-contains-duplicate
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
0378-kth-smallest-element-in-a-sorted-matrix
0435-non-overlapping-intervals
0876-hand-of-straights
0883-car-fleet
1988-minimize-maximum-pair-sum-in-array
2112-minimum-difference-between-highest-and-lowest-of-k-scores
2160-minimum-operations-to-make-a-uni-value-grid
2588-maximum-number-of-points-from-grid-queries
2888-minimum-index-of-a-valid-split
3214-maximize-area-of-square-hole-in-grid

Heap (Priority Queue)

0023-merge-k-sorted-lists
0347-top-k-frequent-elements
0378-kth-smallest-element-in-a-sorted-matrix
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2588-maximum-number-of-points-from-grid-queries
3773-minimum-pair-removal-to-sort-array-i

Matrix

0048-rotate-image
0063-unique-paths-ii
0073-set-matrix-zeroes
0079-word-search
0085-maximal-rectangle
0200-number-of-islands
0212-word-search-ii
0378-kth-smallest-element-in-a-sorted-matrix
0417-pacific-atlantic-water-flow
1413-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2089-maximum-matrix-sum
2160-minimum-operations-to-make-a-uni-value-grid
2588-maximum-number-of-points-from-grid-queries

Dynamic Programming

0005-longest-palindromic-substring
0042-trapping-rain-water
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0062-unique-paths
0063-unique-paths-ii
0070-climbing-stairs
0072-edit-distance
0085-maximal-rectangle
0121-best-time-to-buy-and-sell-stock
0152-maximum-product-subarray
0198-house-robber
0213-house-robber-ii
0300-longest-increasing-subsequence
0322-coin-change
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0474-ones-and-zeroes
0494-target-sum
0516-longest-palindromic-subsequence
0518-coin-change-ii
0647-palindromic-substrings
0712-minimum-ascii-delete-sum-for-two-strings
1250-longest-common-subsequence
1527-number-of-ways-to-paint-n-3-grid
1569-max-dot-product-of-two-subsequences
1631-number-of-sub-arrays-with-odd-sum
2001-jump-game-vii

Greedy

0011-container-with-most-water
0045-jump-game-ii
0055-jump-game
0435-non-overlapping-intervals
0876-hand-of-straights
1988-minimize-maximum-pair-sum-in-array
2089-maximum-matrix-sum

Math

0048-rotate-image
0050-powx-n
0062-unique-paths
0066-plus-one
0070-climbing-stairs
0150-evaluate-reverse-polish-notation
0189-rotate-array
0202-happy-number
0268-missing-number
0371-sum-of-two-integers
0912-random-pick-with-weight
1284-four-divisors
1395-minimum-time-visiting-all-points
1631-number-of-sub-arrays-with-odd-sum
2160-minimum-operations-to-make-a-uni-value-grid
3172-divisible-and-non-divisible-sums-difference
3325-find-the-largest-area-of-square-inside-two-rectangles

Tree

0098-validate-binary-search-tree
0100-same-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0110-balanced-binary-tree
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0297-serialize-and-deserialize-binary-tree
0543-diameter-of-binary-tree
0653-two-sum-iv-input-is-a-bst
0774-maximum-depth-of-n-ary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
1116-maximum-level-sum-of-a-binary-tree
1465-maximum-product-of-splitted-binary-tree

Depth-First Search

0079-word-search
0098-validate-binary-search-tree
0100-same-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0133-clone-graph
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0211-design-add-and-search-words-data-structure
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0297-serialize-and-deserialize-binary-tree
0417-pacific-atlantic-water-flow
0543-diameter-of-binary-tree
0653-two-sum-iv-input-is-a-bst
0774-maximum-depth-of-n-ary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
1116-maximum-level-sum-of-a-binary-tree
1465-maximum-product-of-splitted-binary-tree

Breadth-First Search

0100-same-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0133-clone-graph
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0226-invert-binary-tree
0297-serialize-and-deserialize-binary-tree
0322-coin-change
0417-pacific-atlantic-water-flow
0653-two-sum-iv-input-is-a-bst
0774-maximum-depth-of-n-ary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
1116-maximum-level-sum-of-a-binary-tree
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2588-maximum-number-of-points-from-grid-queries

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0049-group-anagrams
0072-edit-distance
0079-word-search
0125-valid-palindrome
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0212-word-search-ii
0242-valid-anagram
0297-serialize-and-deserialize-binary-tree
0424-longest-repeating-character-replacement
0474-ones-and-zeroes
0481-magical-string
0516-longest-palindromic-subsequence
0567-permutation-in-string
0647-palindromic-substrings
0712-minimum-ascii-delete-sum-for-two-strings
1250-longest-common-subsequence
2001-jump-game-vii

Sliding Window

0003-longest-substring-without-repeating-characters
0424-longest-repeating-character-replacement
0567-permutation-in-string
2001-jump-game-vii
2112-minimum-difference-between-highest-and-lowest-of-k-scores
2255-minimum-swaps-to-group-all-1s-together-ii

Prefix Sum

0238-product-of-array-except-self
0560-subarray-sum-equals-k
0912-random-pick-with-weight
1413-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1631-number-of-sub-arrays-with-odd-sum
2001-jump-game-vii

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0041-first-missing-positive
0049-group-anagrams
0073-set-matrix-zeroes
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0128-longest-consecutive-sequence
0133-clone-graph
0141-linked-list-cycle
0169-majority-element
0202-happy-number
0208-implement-trie-prefix-tree
0217-contains-duplicate
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
0424-longest-repeating-character-replacement
0442-find-all-duplicates-in-an-array
0560-subarray-sum-equals-k
0567-permutation-in-string
0653-two-sum-iv-input-is-a-bst
0876-hand-of-straights
0896-smallest-subtree-with-all-the-deepest-nodes
1001-n-repeated-element-in-size-2n-array
2139-detect-squares
2888-minimum-index-of-a-valid-split
3250-maximum-square-area-by-removing-fences-from-a-field
3773-minimum-pair-removal-to-sort-array-i

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0026-remove-duplicates-from-sorted-array
0042-trapping-rain-water
0125-valid-palindrome
0141-linked-list-cycle
0143-reorder-list
0189-rotate-array
0202-happy-number
0287-find-the-duplicate-number
0481-magical-string
0567-permutation-in-string
0647-palindromic-substrings
0653-two-sum-iv-input-is-a-bst
1988-minimize-maximum-pair-sum-in-array
2588-maximum-number-of-points-from-grid-queries

Union Find

0128-longest-consecutive-sequence
0200-number-of-islands
2588-maximum-number-of-points-from-grid-queries

Linked List

0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0141-linked-list-cycle
0143-reorder-list
0206-reverse-linked-list
3773-minimum-pair-removal-to-sort-array-i

Binary Search Tree

0098-validate-binary-search-tree
0230-kth-smallest-element-in-a-bst
0653-two-sum-iv-input-is-a-bst

Binary Tree

0098-validate-binary-search-tree
0100-same-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0110-balanced-binary-tree
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0297-serialize-and-deserialize-binary-tree
0543-diameter-of-binary-tree
0653-two-sum-iv-input-is-a-bst
0896-smallest-subtree-with-all-the-deepest-nodes
1116-maximum-level-sum-of-a-binary-tree
1465-maximum-product-of-splitted-binary-tree

Divide and Conquer

0004-median-of-two-sorted-arrays
0023-merge-k-sorted-lists
0053-maximum-subarray
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits
0347-top-k-frequent-elements

Merge Sort

0023-merge-k-sorted-lists

Backtracking

0039-combination-sum
0078-subsets
0079-word-search
0212-word-search-ii
0494-target-sum

Bit Manipulation

0078-subsets
0137-single-number-ii
0190-reverse-bits
0191-number-of-1-bits
0268-missing-number
0287-find-the-duplicate-number
0371-sum-of-two-integers
3605-construct-the-minimum-bitwise-array-i

Design

0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0297-serialize-and-deserialize-binary-tree
2139-detect-squares

Trie

0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0212-word-search-ii

Bucket Sort

0164-maximum-gap
0347-top-k-frequent-elements

Counting

0169-majority-element
0347-top-k-frequent-elements
2139-detect-squares

Quickselect

0347-top-k-frequent-elements

Radix Sort

0164-maximum-gap

Combinatorics

0062-unique-paths

Randomized

0912-random-pick-with-weight

Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0143-reorder-list
0150-evaluate-reverse-polish-notation
0883-car-fleet

Recursion

0021-merge-two-sorted-lists
0050-powx-n
0143-reorder-list
0206-reverse-linked-list

Graph

0133-clone-graph
0207-course-schedule
0210-course-schedule-ii
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid

Topological Sort

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

Shortest Path

1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0883-car-fleet

Memoization

0070-climbing-stairs

Geometry

1395-minimum-time-visiting-all-points
3325-find-the-largest-area-of-square-inside-two-rectangles

Segment Tree

3775-separate-squares-ii

Line Sweep

3775-separate-squares-ii

Enumeration

3250-maximum-square-area-by-removing-fences-from-a-field

Database

0584-find-customer-referee

Simulation

3773-minimum-pair-removal-to-sort-array-i

Doubly-Linked List

3773-minimum-pair-removal-to-sort-array-i

Ordered Set

3773-minimum-pair-removal-to-sort-array-i