Completing LeetCode 75🎯

LeetCode Topics

Math

0009-palindrome-number
0048-rotate-image
0050-powx-n
0070-climbing-stairs
0189-rotate-array
0202-happy-number
0227-basic-calculator-ii
0415-add-strings
0670-maximum-swap
0912-random-pick-with-weight
1013-fibonacci-number
1014-k-closest-points-to-origin
1146-greatest-common-divisor-of-strings
1236-n-th-tribonacci-number
1925-count-nice-pairs-in-an-array

Dynamic Programming

0032-longest-valid-parentheses
0042-trapping-rain-water
0070-climbing-stairs
0072-edit-distance
0097-interleaving-string
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0198-house-robber
0213-house-robber-ii
0309-best-time-to-buy-and-sell-stock-with-cooldown
0322-coin-change
0338-counting-bits
0392-is-subsequence
0410-split-array-largest-sum
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0494-target-sum
0518-coin-change-ii
0647-palindromic-substrings
0698-partition-to-k-equal-sum-subsets
0740-delete-and-earn
0747-min-cost-climbing-stairs
0806-domino-and-tromino-tiling
1013-fibonacci-number
1236-n-th-tribonacci-number
1250-longest-common-subsequence
1474-longest-zigzag-path-in-a-binary-tree
1586-longest-subarray-of-1s-after-deleting-one-element
2648-number-of-ways-to-earn-points

Memoization

0070-climbing-stairs
0698-partition-to-k-equal-sum-subsets
1013-fibonacci-number
1236-n-th-tribonacci-number

Two Pointers

0011-container-with-most-water
0019-remove-nth-node-from-end-of-list
0028-find-the-index-of-the-first-occurrence-in-a-string
0031-next-permutation
0042-trapping-rain-water
0075-sort-colors
0088-merge-sorted-array
0125-valid-palindrome
0148-sort-list
0151-reverse-words-in-a-string
0189-rotate-array
0202-happy-number
0283-move-zeroes
0345-reverse-vowels-of-a-string
0392-is-subsequence
0443-string-compression
0611-valid-triangle-number
0647-palindromic-substrings
0680-valid-palindrome-ii
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1798-max-number-of-k-sum-pairs
1894-merge-strings-alternately
1972-rotating-the-box
2216-delete-the-middle-node-of-a-linked-list
2232-adding-spaces-to-a-string
2236-maximum-twin-sum-of-a-linked-list
2392-successful-pairs-of-spells-and-potions
2414-move-pieces-to-obtain-a-string
2553-total-cost-to-hire-k-workers
3018-make-string-a-subsequence-using-cyclic-increments

String

0003-longest-substring-without-repeating-characters
0017-letter-combinations-of-a-phone-number
0028-find-the-index-of-the-first-occurrence-in-a-string
0032-longest-valid-parentheses
0071-simplify-path
0072-edit-distance
0076-minimum-window-substring
0097-interleaving-string
0125-valid-palindrome
0151-reverse-words-in-a-string
0208-implement-trie-prefix-tree
0227-basic-calculator-ii
0345-reverse-vowels-of-a-string
0392-is-subsequence
0394-decode-string
0399-evaluate-division
0415-add-strings
0443-string-compression
0647-palindromic-substrings
0649-dota2-senate
0680-valid-palindrome-ii
0807-custom-sort-string
0851-goat-latin
0957-minimum-add-to-make-parentheses-valid
1146-greatest-common-divisor-of-strings
1250-longest-common-subsequence
1371-minimum-remove-to-make-valid-parentheses
1397-search-suggestions-system
1512-design-underground-system
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1777-determine-if-two-strings-are-close
1894-merge-strings-alternately
2220-find-all-possible-recipes-from-given-supplies
2232-adding-spaces-to-a-string
2414-move-pieces-to-obtain-a-string
2470-removing-stars-from-a-string
2828-lexicographically-smallest-string-after-substring-operation
3018-make-string-a-subsequence-using-cyclic-increments

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence

Array

0001-two-sum
0011-container-with-most-water
0031-next-permutation
0034-find-first-and-last-position-of-element-in-sorted-array
0042-trapping-rain-water
0048-rotate-image
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0108-convert-sorted-array-to-binary-search-tree
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0130-surrounded-regions
0134-gas-station
0136-single-number
0162-find-peak-element
0189-rotate-array
0198-house-robber
0200-number-of-islands
0213-house-robber-ii
0215-kth-largest-element-in-an-array
0216-combination-sum-iii
0217-contains-duplicate
0238-product-of-array-except-self
0283-move-zeroes
0309-best-time-to-buy-and-sell-stock-with-cooldown
0322-coin-change
0334-increasing-triplet-subsequence
0347-top-k-frequent-elements
0399-evaluate-division
0410-split-array-largest-sum
0416-partition-equal-subset-sum
0417-pacific-atlantic-water-flow
0435-non-overlapping-intervals
0452-minimum-number-of-arrows-to-burst-balloons
0494-target-sum
0518-coin-change-ii
0560-subarray-sum-equals-k
0605-can-place-flowers
0611-valid-triangle-number
0636-exclusive-time-of-functions
0643-maximum-average-subarray-i
0695-max-area-of-island
0698-partition-to-k-equal-sum-subsets
0724-find-pivot-index
0735-asteroid-collision
0739-daily-temperatures
0740-delete-and-earn
0747-min-cost-climbing-stairs
0792-binary-search
0906-walking-robot-simulation
0907-koko-eating-bananas
0912-random-pick-with-weight
0948-sort-an-array
1014-k-closest-points-to-origin
1016-subarray-sums-divisible-by-k
1036-rotting-oranges
1046-max-consecutive-ones-iii
1171-shortest-path-in-binary-matrix
1319-unique-number-of-occurrences
1392-find-the-difference-of-two-arrays
1397-search-suggestions-system
1528-kids-with-the-greatest-number-of-candies
1586-longest-subarray-of-1s-after-deleting-one-element
1646-kth-missing-positive-number
1798-max-number-of-k-sum-pairs
1833-find-the-highest-altitude
1925-count-nice-pairs-in-an-array
1972-rotating-the-box
2038-nearest-exit-from-entrance-in-maze
2169-simple-bank-system
2220-find-all-possible-recipes-from-given-supplies
2232-adding-spaces-to-a-string
2392-successful-pairs-of-spells-and-potions
2428-equal-row-and-column-pairs
2553-total-cost-to-hire-k-workers
2636-maximum-subsequence-score
2648-number-of-ways-to-earn-points

Simulation

0415-add-strings
0735-asteroid-collision
0906-walking-robot-simulation
2169-simple-bank-system
2232-adding-spaces-to-a-string
2428-equal-row-and-column-pairs
2470-removing-stars-from-a-string
2553-total-cost-to-hire-k-workers

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0017-letter-combinations-of-a-phone-number
0076-minimum-window-substring
0133-clone-graph
0138-copy-list-with-random-pointer
0146-lru-cache
0202-happy-number
0208-implement-trie-prefix-tree
0217-contains-duplicate
0347-top-k-frequent-elements
0355-design-twitter
0560-subarray-sum-equals-k
0740-delete-and-earn
0807-custom-sort-string
0906-walking-robot-simulation
1016-subarray-sums-divisible-by-k
1319-unique-number-of-occurrences
1392-find-the-difference-of-two-arrays
1512-design-underground-system
1777-determine-if-two-strings-are-close
1798-max-number-of-k-sum-pairs
1925-count-nice-pairs-in-an-array
2169-simple-bank-system
2220-find-all-possible-recipes-from-given-supplies
2413-smallest-number-in-infinite-set
2428-equal-row-and-column-pairs

Sorting

0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0148-sort-list
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0347-top-k-frequent-elements
0435-non-overlapping-intervals
0452-minimum-number-of-arrows-to-burst-balloons
0611-valid-triangle-number
0807-custom-sort-string
0948-sort-an-array
1014-k-closest-points-to-origin
1397-search-suggestions-system
1777-determine-if-two-strings-are-close
1798-max-number-of-k-sum-pairs
2392-successful-pairs-of-spells-and-potions
2636-maximum-subsequence-score

Recursion

0050-powx-n
0206-reverse-linked-list
0394-decode-string
1013-fibonacci-number

Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0108-convert-sorted-array-to-binary-search-tree
0110-balanced-binary-tree
0129-sum-root-to-leaf-numbers
0199-binary-tree-right-side-view
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0437-path-sum-iii
0450-delete-node-in-a-bst
0543-diameter-of-binary-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0904-leaf-similar-trees
0975-range-sum-of-bst
0998-check-completeness-of-a-binary-tree
1116-maximum-level-sum-of-a-binary-tree
1474-longest-zigzag-path-in-a-binary-tree
1544-count-good-nodes-in-binary-tree
2347-count-nodes-equal-to-average-of-subtree
2493-reverse-odd-levels-of-binary-tree

Depth-First Search

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0129-sum-root-to-leaf-numbers
0130-surrounded-regions
0133-clone-graph
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0399-evaluate-division
0417-pacific-atlantic-water-flow
0437-path-sum-iii
0543-diameter-of-binary-tree
0547-number-of-provinces
0695-max-area-of-island
0766-flatten-a-multilevel-doubly-linked-list
0801-is-graph-bipartite
0871-keys-and-rooms
0904-leaf-similar-trees
0975-range-sum-of-bst
1116-maximum-level-sum-of-a-binary-tree
1474-longest-zigzag-path-in-a-binary-tree
1544-count-good-nodes-in-binary-tree
1576-reorder-routes-to-make-all-paths-lead-to-the-city-zero
2347-count-nodes-equal-to-average-of-subtree
2493-reverse-odd-levels-of-binary-tree

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0130-surrounded-regions
0133-clone-graph
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0226-invert-binary-tree
0322-coin-change
0399-evaluate-division
0417-pacific-atlantic-water-flow
0547-number-of-provinces
0695-max-area-of-island
0801-is-graph-bipartite
0871-keys-and-rooms
0998-check-completeness-of-a-binary-tree
1036-rotting-oranges
1116-maximum-level-sum-of-a-binary-tree
1171-shortest-path-in-binary-matrix
1544-count-good-nodes-in-binary-tree
1576-reorder-routes-to-make-all-paths-lead-to-the-city-zero
2038-nearest-exit-from-entrance-in-maze
2493-reverse-odd-levels-of-binary-tree

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
0108-convert-sorted-array-to-binary-search-tree
0110-balanced-binary-tree
0129-sum-root-to-leaf-numbers
0199-binary-tree-right-side-view
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0437-path-sum-iii
0450-delete-node-in-a-bst
0543-diameter-of-binary-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0904-leaf-similar-trees
0975-range-sum-of-bst
0998-check-completeness-of-a-binary-tree
1116-maximum-level-sum-of-a-binary-tree
1474-longest-zigzag-path-in-a-binary-tree
1544-count-good-nodes-in-binary-tree
2347-count-nodes-equal-to-average-of-subtree
2493-reverse-odd-levels-of-binary-tree

Binary Search

0034-find-first-and-last-position-of-element-in-sorted-array
0162-find-peak-element
0374-guess-number-higher-or-lower
0410-split-array-largest-sum
0611-valid-triangle-number
0792-binary-search
0907-koko-eating-bananas
0912-random-pick-with-weight
1046-max-consecutive-ones-iii
1397-search-suggestions-system
1646-kth-missing-positive-number
2392-successful-pairs-of-spells-and-potions

Greedy

0011-container-with-most-water
0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0334-increasing-triplet-subsequence
0410-split-array-largest-sum
0435-non-overlapping-intervals
0452-minimum-number-of-arrows-to-burst-balloons
0605-can-place-flowers
0611-valid-triangle-number
0649-dota2-senate
0670-maximum-swap
0680-valid-palindrome-ii
0957-minimum-add-to-make-parentheses-valid
2636-maximum-subsequence-score
2828-lexicographically-smallest-string-after-substring-operation

Divide and Conquer

0108-convert-sorted-array-to-binary-search-tree
0148-sort-list
0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
0948-sort-an-array
1014-k-closest-points-to-origin

Binary Search Tree

0108-convert-sorted-array-to-binary-search-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0450-delete-node-in-a-bst
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0975-range-sum-of-bst

Linked List

0019-remove-nth-node-from-end-of-list
0138-copy-list-with-random-pointer
0146-lru-cache
0148-sort-list
0206-reverse-linked-list
0328-odd-even-linked-list
0355-design-twitter
0766-flatten-a-multilevel-doubly-linked-list
2216-delete-the-middle-node-of-a-linked-list
2236-maximum-twin-sum-of-a-linked-list

Merge Sort

0148-sort-list
0948-sort-an-array

Prefix Sum

0238-product-of-array-except-self
0410-split-array-largest-sum
0560-subarray-sum-equals-k
0724-find-pivot-index
0912-random-pick-with-weight
1016-subarray-sums-divisible-by-k
1046-max-consecutive-ones-iii
1833-find-the-highest-altitude

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
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
1777-determine-if-two-strings-are-close
1925-count-nice-pairs-in-an-array

Stack

0032-longest-valid-parentheses
0042-trapping-rain-water
0071-simplify-path
0094-binary-tree-inorder-traversal
0227-basic-calculator-ii
0394-decode-string
0636-exclusive-time-of-functions
0735-asteroid-collision
0739-daily-temperatures
0937-online-stock-span
0957-minimum-add-to-make-parentheses-valid
1371-minimum-remove-to-make-valid-parentheses
2236-maximum-twin-sum-of-a-linked-list
2470-removing-stars-from-a-string

Matrix

0048-rotate-image
0130-surrounded-regions
0200-number-of-islands
0417-pacific-atlantic-water-flow
0695-max-area-of-island
1036-rotting-oranges
1171-shortest-path-in-binary-matrix
1972-rotating-the-box
2038-nearest-exit-from-entrance-in-maze
2428-equal-row-and-column-pairs

Bit Manipulation

0136-single-number
0338-counting-bits
0698-partition-to-k-equal-sum-subsets
1441-minimum-flips-to-make-a-or-b-equal-to-c
3508-number-of-bit-changes-to-make-two-integers-equal

Design

0146-lru-cache
0208-implement-trie-prefix-tree
0355-design-twitter
0937-online-stock-span
0969-number-of-recent-calls
1512-design-underground-system
2169-simple-bank-system
2413-smallest-number-in-infinite-set

Queue

0649-dota2-senate
0969-number-of-recent-calls

Data Stream

0937-online-stock-span
0969-number-of-recent-calls

Interactive

0374-guess-number-higher-or-lower

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
0355-design-twitter
0948-sort-an-array
1014-k-closest-points-to-origin
1397-search-suggestions-system
2413-smallest-number-in-infinite-set
2553-total-cost-to-hire-k-workers
2636-maximum-subsequence-score

Quickselect

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
1014-k-closest-points-to-origin

Ordered Set

2413-smallest-number-in-infinite-set

Backtracking

0017-letter-combinations-of-a-phone-number
0216-combination-sum-iii
0494-target-sum
0698-partition-to-k-equal-sum-subsets

Graph

0133-clone-graph
0207-course-schedule
0399-evaluate-division
0547-number-of-provinces
0801-is-graph-bipartite
0871-keys-and-rooms
1576-reorder-routes-to-make-all-paths-lead-to-the-city-zero
2220-find-all-possible-recipes-from-given-supplies

Union Find

0130-surrounded-regions
0200-number-of-islands
0399-evaluate-division
0547-number-of-provinces
0695-max-area-of-island
0801-is-graph-bipartite

Shortest Path

0399-evaluate-division

Trie

0208-implement-trie-prefix-tree
1397-search-suggestions-system

Database

1827-invalid-tweets

Monotonic Stack

0042-trapping-rain-water
0739-daily-temperatures
0937-online-stock-span

Bitmask

0698-partition-to-k-equal-sum-subsets

Bucket Sort

0347-top-k-frequent-elements
0948-sort-an-array

Radix Sort

0948-sort-an-array

Counting Sort

0948-sort-an-array

Doubly-Linked List

0146-lru-cache
0766-flatten-a-multilevel-doubly-linked-list

Geometry

1014-k-closest-points-to-origin

Topological Sort

0207-course-schedule
2220-find-all-possible-recipes-from-given-supplies

Randomized

0912-random-pick-with-weight