LeetCode-problems

LeetCode problems solved to demonstrate and track progress

LeetCode Topics

Array

0001-two-sum
0011-container-with-most-water
0014-longest-common-prefix
0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0036-valid-sudoku
0042-trapping-rain-water
0045-jump-game-ii
0048-rotate-image
0049-group-anagrams
0054-spiral-matrix
0055-jump-game
0056-merge-intervals
0057-insert-interval
0063-unique-paths-ii
0064-minimum-path-sum
0066-plus-one
0068-text-justification
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0128-longest-consecutive-sequence
0130-surrounded-regions
0134-gas-station
0135-candy
0136-single-number
0137-single-number-ii
0139-word-break
0149-max-points-on-a-line
0150-evaluate-reverse-polish-notation
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0189-rotate-array
0198-house-robber
0200-number-of-islands
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0228-summary-ranges
0238-product-of-array-except-self
0274-h-index
0283-move-zeroes
0289-game-of-life
0300-longest-increasing-subsequence
0322-coin-change
0334-increasing-triplet-subsequence
0380-insert-delete-getrandom-o1
0399-evaluate-division
0452-minimum-number-of-arrows-to-burst-balloons
0605-can-place-flowers
0724-find-pivot-index
0735-asteroid-collision
0739-daily-temperatures
0746-min-cost-climbing-stairs
1207-unique-number-of-occurrences
1431-kids-with-the-greatest-number-of-candies
1679-max-number-of-k-sum-pairs
1732-find-the-highest-altitude
2215-find-the-difference-of-two-arrays
2352-equal-row-and-column-pairs

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0042-trapping-rain-water
0061-rotate-list
0080-remove-duplicates-from-sorted-array-ii
0082-remove-duplicates-from-sorted-list-ii
0086-partition-list
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0148-sort-list
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0202-happy-number
0283-move-zeroes
0345-reverse-vowels-of-a-string
0392-is-subsequence
0443-string-compression
1679-max-number-of-k-sum-pairs
1768-merge-strings-alternately
2095-delete-the-middle-node-of-a-linked-list
2130-maximum-twin-sum-of-a-linked-list

Sorting

0015-3sum
0049-group-anagrams
0056-merge-intervals
0088-merge-sorted-array
0148-sort-list
0169-majority-element
0242-valid-anagram
0274-h-index
0452-minimum-number-of-arrows-to-burst-balloons
1657-determine-if-two-strings-are-close
1679-max-number-of-k-sum-pairs

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0030-substring-with-concatenation-of-all-words
0036-valid-sudoku
0049-group-anagrams
0073-set-matrix-zeroes
0076-minimum-window-substring
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0128-longest-consecutive-sequence
0133-clone-graph
0138-copy-list-with-random-pointer
0139-word-break
0141-linked-list-cycle
0146-lru-cache
0149-max-points-on-a-line
0169-majority-element
0202-happy-number
0205-isomorphic-strings
0219-contains-duplicate-ii
0242-valid-anagram
0290-word-pattern
0380-insert-delete-getrandom-o1
0383-ransom-note
1207-unique-number-of-occurrences
1657-determine-if-two-strings-are-close
1679-max-number-of-k-sum-pairs
2215-find-the-difference-of-two-arrays
2352-equal-row-and-column-pairs

Divide and Conquer

0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0148-sort-list
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits

Counting

0169-majority-element
0383-ransom-note
1657-determine-if-two-strings-are-close

Math

0002-add-two-numbers
0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0048-rotate-image
0050-powx-n
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0149-max-points-on-a-line
0150-evaluate-reverse-polish-notation
0172-factorial-trailing-zeroes
0189-rotate-array
0202-happy-number
0380-insert-delete-getrandom-o1
1071-greatest-common-divisor-of-strings
1137-n-th-tribonacci-number

Dynamic Programming

0005-longest-palindromic-substring
0042-trapping-rain-water
0045-jump-game-ii
0055-jump-game
0063-unique-paths-ii
0064-minimum-path-sum
0070-climbing-stairs
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0139-word-break
0198-house-robber
0300-longest-increasing-subsequence
0322-coin-change
0392-is-subsequence
0746-min-cost-climbing-stairs
1137-n-th-tribonacci-number

Greedy

0011-container-with-most-water
0045-jump-game-ii
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0135-candy
0334-increasing-triplet-subsequence
0452-minimum-number-of-arrows-to-burst-balloons
0605-can-place-flowers
0649-dota2-senate

Counting Sort

0274-h-index

Design

0146-lru-cache
0155-min-stack
0173-binary-search-tree-iterator
0380-insert-delete-getrandom-o1
0933-number-of-recent-calls

Randomized

0380-insert-delete-getrandom-o1

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0724-find-pivot-index
1732-find-the-highest-altitude

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0006-zigzag-conversion
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0020-valid-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0030-substring-with-concatenation-of-all-words
0049-group-anagrams
0058-length-of-last-word
0067-add-binary
0068-text-justification
0071-simplify-path
0076-minimum-window-substring
0125-valid-palindrome
0139-word-break
0151-reverse-words-in-a-string
0205-isomorphic-strings
0242-valid-anagram
0290-word-pattern
0345-reverse-vowels-of-a-string
0383-ransom-note
0392-is-subsequence
0399-evaluate-division
0443-string-compression
0649-dota2-senate
1071-greatest-common-divisor-of-strings
1657-determine-if-two-strings-are-close
1768-merge-strings-alternately
2390-removing-stars-from-a-string

Trie

0014-longest-common-prefix
0139-word-break

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string

Simulation

0054-spiral-matrix
0067-add-binary
0068-text-justification
0289-game-of-life
0735-asteroid-collision
2352-equal-row-and-column-pairs
2390-removing-stars-from-a-string

Stack

0020-valid-parentheses
0042-trapping-rain-water
0071-simplify-path
0114-flatten-binary-tree-to-linked-list
0150-evaluate-reverse-polish-notation
0155-min-stack
0173-binary-search-tree-iterator
0735-asteroid-collision
0739-daily-temperatures
2130-maximum-twin-sum-of-a-linked-list
2390-removing-stars-from-a-string

Monotonic Stack

0042-trapping-rain-water
0739-daily-temperatures

Binary Search

0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0069-sqrtx
0074-search-a-2d-matrix
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0222-count-complete-tree-nodes
0300-longest-increasing-subsequence

Sliding Window

0003-longest-substring-without-repeating-characters
0030-substring-with-concatenation-of-all-words
0076-minimum-window-substring
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii

Matrix

0036-valid-sudoku
0048-rotate-image
0054-spiral-matrix
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0130-surrounded-regions
0200-number-of-islands
0289-game-of-life
2352-equal-row-and-column-pairs

Union Find

0128-longest-consecutive-sequence

Database

1757-recyclable-and-low-fat-products

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0025-reverse-nodes-in-k-group
0061-rotate-list
0082-remove-duplicates-from-sorted-list-ii
0086-partition-list
0092-reverse-linked-list-ii
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0146-lru-cache
0148-sort-list
0206-reverse-linked-list
0328-odd-even-linked-list
2095-delete-the-middle-node-of-a-linked-list
2130-maximum-twin-sum-of-a-linked-list

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0025-reverse-nodes-in-k-group
0050-powx-n
0206-reverse-linked-list

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
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0129-sum-root-to-leaf-numbers
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0530-minimum-absolute-difference-in-bst
0637-average-of-levels-in-binary-tree
0700-search-in-a-binary-search-tree
0872-leaf-similar-trees

Depth-First Search

0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
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
0210-course-schedule-ii
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0399-evaluate-division
0530-minimum-absolute-difference-in-bst
0637-average-of-levels-in-binary-tree
0872-leaf-similar-trees

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
0112-path-sum
0117-populating-next-right-pointers-in-each-node-ii
0130-surrounded-regions
0133-clone-graph
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0226-invert-binary-tree
0322-coin-change
0399-evaluate-division
0530-minimum-absolute-difference-in-bst
0637-average-of-levels-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
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0129-sum-root-to-leaf-numbers
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0530-minimum-absolute-difference-in-bst
0637-average-of-levels-in-binary-tree
0700-search-in-a-binary-search-tree
0872-leaf-similar-trees

Binary Search Tree

0098-validate-binary-search-tree
0108-convert-sorted-array-to-binary-search-tree
0173-binary-search-tree-iterator
0230-kth-smallest-element-in-a-bst
0530-minimum-absolute-difference-in-bst
0700-search-in-a-binary-search-tree

Union-Find

0130-surrounded-regions
0200-number-of-islands
0399-evaluate-division

Doubly-Linked List

0146-lru-cache

Bit Manipulation

0067-add-binary
0136-single-number
0137-single-number-ii
0190-reverse-bits
0191-number-of-1-bits
0201-bitwise-and-of-numbers-range
0222-count-complete-tree-nodes

Graph Theory

0133-clone-graph
0207-course-schedule
0210-course-schedule-ii
0399-evaluate-division

Memoization

0070-climbing-stairs
0139-word-break
1137-n-th-tribonacci-number

Shortest Path

0399-evaluate-division

Topological Sort

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

Iterator

0173-binary-search-tree-iterator

Merge Sort

0148-sort-list

Geometry

0149-max-points-on-a-line

Queue

0649-dota2-senate
0933-number-of-recent-calls

Data Stream

0933-number-of-recent-calls