Leetcode

LeetCode Topics

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0059-spiral-matrix-ii
0066-plus-one
0136-single-number
0228-summary-ranges
0268-missing-number
0283-move-zeroes
0349-intersection-of-two-arrays
0496-next-greater-element-i
0682-baseball-game
0733-flood-fill
0777-toeplitz-matrix
0898-transpose-matrix
1241-decompress-run-length-encoded-list
1421-find-numbers-with-even-number-of-digits
1476-count-negative-numbers-in-a-sorted-matrix
1482-how-many-numbers-are-smaller-than-the-current-number
1505-create-target-array-in-the-given-order
1528-kids-with-the-greatest-number-of-candies
1574-maximum-product-of-two-elements-in-an-array
1651-shuffle-string
1677-matrix-diagonal-sum
1720-crawler-log-folder
1742-widest-vertical-area-between-two-points-containing-no-points
1786-count-the-number-of-consistent-strings
1802-number-of-students-unable-to-eat-lunch
1839-decode-xored-array
1848-sum-of-unique-elements
1899-count-items-matching-a-rule
1944-truncate-sentence
2048-build-array-from-permutation
2106-find-greatest-common-divisor-of-array
2116-count-number-of-pairs-with-absolute-difference-k
2137-final-value-of-variable-after-performing-operations
2231-find-first-palindromic-string-in-the-array
2244-number-of-laser-beams-in-a-bank
2292-counting-words-with-a-given-prefix
2308-divide-array-into-equal-pairs
2412-minimum-amount-of-time-to-fill-cups
2436-make-array-zero-by-subtracting-equal-amounts
2502-sort-the-people
2585-delete-greatest-value-in-each-row
2692-take-gifts-from-the-richest-pile
2714-left-and-right-sum-differences
2917-count-pairs-whose-sum-is-less-than-target
3093-sum-of-values-at-indices-with-k-set-bits
3194-find-words-containing-character
3226-minimum-number-game
3242-count-elements-with-maximum-frequency
3331-minimum-operations-to-exceed-threshold-value-i
3446-find-the-number-of-good-pairs-i
3515-find-if-digit-game-can-be-won
3533-snake-in-matrix
3581-the-two-sneaky-numbers-of-digitville
3582-find-indices-of-stable-mountains
3778-transform-array-by-parity
3846-minimum-operations-to-make-array-sum-divisible-by-k

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0222-count-complete-tree-nodes
0268-missing-number
0349-intersection-of-two-arrays
1476-count-negative-numbers-in-a-sorted-matrix
2917-count-pairs-whose-sum-is-less-than-target

Divide and Conquer

0004-median-of-two-sorted-arrays

Math

0002-add-two-numbers
0013-roman-to-integer
0043-multiply-strings
0066-plus-one
0268-missing-number
0292-nim-game
0326-power-of-three
0412-fizz-buzz
0445-add-two-numbers-ii
1013-fibonacci-number
1411-convert-binary-number-in-a-linked-list-to-integer
1421-find-numbers-with-even-number-of-digits
1448-maximum-69-number
2106-find-greatest-common-divisor-of-array
2238-a-number-after-a-double-reversal
2244-number-of-laser-beams-in-a-bank
2903-insert-greatest-common-divisors-in-linked-list
3172-divisible-and-non-divisible-sums-difference
3515-find-if-digit-game-can-be-won
3581-the-two-sneaky-numbers-of-digitville
3846-minimum-operations-to-make-array-sum-divisible-by-k

Number Theory

2106-find-greatest-common-divisor-of-array
2903-insert-greatest-common-divisors-in-linked-list

String

0005-longest-palindromic-substring
0006-zigzag-conversion
0013-roman-to-integer
0020-valid-parentheses
0043-multiply-strings
0151-reverse-words-in-a-string
0412-fizz-buzz
0557-reverse-words-in-a-string-iii
0742-to-lower-case
0782-jewels-and-stones
0874-backspace-string-compare
0920-uncommon-words-from-two-sentences
1128-remove-all-adjacent-duplicates-in-string
1156-occurrences-after-bigram
1651-shuffle-string
1666-make-the-string-great
1720-crawler-log-folder
1737-maximum-nesting-depth-of-the-parentheses
1786-count-the-number-of-consistent-strings
1899-count-items-matching-a-rule
1944-truncate-sentence
1960-check-if-the-sentence-is-pangram
2021-remove-all-occurrences-of-a-substring
2053-check-if-all-characters-have-equal-number-of-occurrences
2128-reverse-prefix-of-word
2137-final-value-of-variable-after-performing-operations
2231-find-first-palindromic-string-in-the-array
2244-number-of-laser-beams-in-a-bank
2292-counting-words-with-a-given-prefix
2406-decode-the-message
2502-sort-the-people
2886-faulty-keyboard
3194-find-words-containing-character
3379-score-of-a-string
3412-permutation-difference-between-two-strings
3533-snake-in-matrix
3811-reverse-degree-of-a-string

Design

0232-implement-queue-using-stacks
1708-design-parking-system

Simulation

0043-multiply-strings
0059-spiral-matrix-ii
0412-fizz-buzz
0682-baseball-game
0874-backspace-string-compare
0898-transpose-matrix
1505-create-target-array-in-the-given-order
1708-design-parking-system
1802-number-of-students-unable-to-eat-lunch
2021-remove-all-occurrences-of-a-substring
2048-build-array-from-permutation
2137-final-value-of-variable-after-performing-operations
2299-merge-nodes-in-between-zeros
2436-make-array-zero-by-subtracting-equal-amounts
2585-delete-greatest-value-in-each-row
2692-take-gifts-from-the-richest-pile
2886-faulty-keyboard
3226-minimum-number-game
3533-snake-in-matrix
3811-reverse-degree-of-a-string

Counting

0920-uncommon-words-from-two-sentences
1708-design-parking-system
1786-count-the-number-of-consistent-strings
1848-sum-of-unique-elements
2053-check-if-all-characters-have-equal-number-of-occurrences
2116-count-number-of-pairs-with-absolute-difference-k
2308-divide-array-into-equal-pairs
3242-count-elements-with-maximum-frequency
3778-transform-array-by-parity

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0019-remove-nth-node-from-end-of-list
0141-linked-list-cycle
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0234-palindrome-linked-list
0283-move-zeroes
0349-intersection-of-two-arrays
0557-reverse-words-in-a-string-iii
0874-backspace-string-compare
0908-middle-of-the-linked-list
2128-reverse-prefix-of-word
2216-delete-the-middle-node-of-a-linked-list
2231-find-first-palindromic-string-in-the-array
2236-maximum-twin-sum-of-a-linked-list
2917-count-pairs-whose-sum-is-less-than-target

Sorting

0268-missing-number
0349-intersection-of-two-arrays
1482-how-many-numbers-are-smaller-than-the-current-number
1574-maximum-product-of-two-elements-in-an-array
1742-widest-vertical-area-between-two-points-containing-no-points
2412-minimum-amount-of-time-to-fill-cups
2436-make-array-zero-by-subtracting-equal-amounts
2502-sort-the-people
2585-delete-greatest-value-in-each-row
2917-count-pairs-whose-sum-is-less-than-target
3226-minimum-number-game
3778-transform-array-by-parity

Graph

1916-find-center-of-star-graph

Hash Table

0001-two-sum
0013-roman-to-integer
0141-linked-list-cycle
0160-intersection-of-two-linked-lists
0268-missing-number
0349-intersection-of-two-arrays
0496-next-greater-element-i
0782-jewels-and-stones
0920-uncommon-words-from-two-sentences
1482-how-many-numbers-are-smaller-than-the-current-number
1786-count-the-number-of-consistent-strings
1848-sum-of-unique-elements
1960-check-if-the-sentence-is-pangram
2053-check-if-all-characters-have-equal-number-of-occurrences
2116-count-number-of-pairs-with-absolute-difference-k
2308-divide-array-into-equal-pairs
2406-decode-the-message
2436-make-array-zero-by-subtracting-equal-amounts
2502-sort-the-people
3242-count-elements-with-maximum-frequency
3412-permutation-difference-between-two-strings
3446-find-the-number-of-good-pairs-i
3581-the-two-sneaky-numbers-of-digitville

Greedy

0011-container-with-most-water
1448-maximum-69-number
2412-minimum-amount-of-time-to-fill-cups
2436-make-array-zero-by-subtracting-equal-amounts

Stack

0020-valid-parentheses
0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0445-add-two-numbers-ii
0496-next-greater-element-i
0682-baseball-game
0874-backspace-string-compare
1128-remove-all-adjacent-duplicates-in-string
1666-make-the-string-great
1720-crawler-log-folder
1737-maximum-nesting-depth-of-the-parentheses
1802-number-of-students-unable-to-eat-lunch
2021-remove-all-occurrences-of-a-substring
2128-reverse-prefix-of-word
2236-maximum-twin-sum-of-a-linked-list

Dynamic Programming

0005-longest-palindromic-substring
0338-counting-bits
1013-fibonacci-number

Queue

0232-implement-queue-using-stacks
1802-number-of-students-unable-to-eat-lunch

Monotonic Stack

0496-next-greater-element-i

Heap (Priority Queue)

1574-maximum-product-of-two-elements-in-an-array
2412-minimum-amount-of-time-to-fill-cups
2436-make-array-zero-by-subtracting-equal-amounts
2585-delete-greatest-value-in-each-row
2692-take-gifts-from-the-richest-pile
3226-minimum-number-game

Matrix

0059-spiral-matrix-ii
0733-flood-fill
0777-toeplitz-matrix
0898-transpose-matrix
1476-count-negative-numbers-in-a-sorted-matrix
1677-matrix-diagonal-sum
2244-number-of-laser-beams-in-a-bank
2585-delete-greatest-value-in-each-row

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0083-remove-duplicates-from-sorted-list
0141-linked-list-cycle
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0445-add-two-numbers-ii
0908-middle-of-the-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer
1765-merge-in-between-linked-lists
2216-delete-the-middle-node-of-a-linked-list
2236-maximum-twin-sum-of-a-linked-list
2299-merge-nodes-in-between-zeros
2903-insert-greatest-common-divisors-in-linked-list

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0206-reverse-linked-list
0234-palindrome-linked-list
0326-power-of-three
1013-fibonacci-number

Tree

0094-binary-tree-inorder-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0222-count-complete-tree-nodes
0226-invert-binary-tree
2384-root-equals-sum-of-children

Depth-First Search

0094-binary-tree-inorder-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0226-invert-binary-tree
0733-flood-fill

Binary Tree

0094-binary-tree-inorder-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0222-count-complete-tree-nodes
0226-invert-binary-tree
2384-root-equals-sum-of-children

Breadth-First Search

0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0226-invert-binary-tree
0733-flood-fill

Bit Manipulation

0136-single-number
0222-count-complete-tree-nodes
0268-missing-number
0338-counting-bits
0461-hamming-distance
1786-count-the-number-of-consistent-strings
1839-decode-xored-array
2308-divide-array-into-equal-pairs
2323-minimum-bit-flips-to-convert-number
3093-sum-of-values-at-indices-with-k-set-bits

Memoization

1013-fibonacci-number

Brainteaser

0292-nim-game

Game Theory

0292-nim-game

String Matching

2292-counting-words-with-a-given-prefix

Counting Sort

1482-how-many-numbers-are-smaller-than-the-current-number

Prefix Sum

2714-left-and-right-sum-differences