LC

A collection of LeetCode questions to ace the coding interview! - Created using LeetHub v2

LeetCode Topics

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0036-valid-sudoku
0049-group-anagrams
0073-set-matrix-zeroes
0128-longest-consecutive-sequence
0141-linked-list-cycle
0142-linked-list-cycle-ii
0169-majority-element
0205-isomorphic-strings
0217-contains-duplicate
0219-contains-duplicate-ii
0229-majority-element-ii
0242-valid-anagram
0349-intersection-of-two-arrays
0383-ransom-note
0409-longest-palindrome
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0451-sort-characters-by-frequency
0560-subarray-sum-equals-k
0567-permutation-in-string
1319-unique-number-of-occurrences
1556-make-two-arrays-equal-by-reversing-subarrays
1635-number-of-good-pairs
1786-count-the-number-of-consistent-strings
3420-find-occurrences-of-an-element-in-an-array

String

0003-longest-substring-without-repeating-characters
0014-longest-common-prefix
0020-valid-parentheses
0049-group-anagrams
0151-reverse-words-in-a-string
0205-isomorphic-strings
0242-valid-anagram
0273-integer-to-english-words
0383-ransom-note
0409-longest-palindrome
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0443-string-compression
0451-sort-characters-by-frequency
0567-permutation-in-string
0647-palindromic-substrings
0796-rotate-string
0812-rotate-string
1021-remove-outermost-parentheses
1524-string-matching-in-an-array
1534-minimum-number-of-frogs-croaking
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1781-check-if-two-string-arrays-are-equivalent
1786-count-the-number-of-consistent-strings
1903-largest-odd-number-in-string
2727-number-of-senior-citizens
3235-minimum-cost-to-convert-string-i

Sliding Window

0003-longest-substring-without-repeating-characters
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0567-permutation-in-string
0643-maximum-average-subarray-i
1567-maximum-number-of-vowels-in-a-substring-of-given-length
2255-minimum-swaps-to-group-all-1s-together-ii

Array

0001-two-sum
0011-container-with-most-water
0014-longest-common-prefix
0015-3sum
0031-next-permutation
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0036-valid-sudoku
0040-combination-sum-ii
0042-trapping-rain-water
0048-rotate-image
0049-group-anagrams
0055-jump-game
0066-plus-one
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0075-sort-colors
0081-search-in-rotated-sorted-array-ii
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0189-rotate-array
0204-count-primes
0209-minimum-size-subarray-sum
0217-contains-duplicate
0219-contains-duplicate-ii
0229-majority-element-ii
0260-single-number-iii
0283-move-zeroes
0349-intersection-of-two-arrays
0485-max-consecutive-ones
0540-single-element-in-a-sorted-array
0560-subarray-sum-equals-k
0643-maximum-average-subarray-i
0729-my-calendar-i
0735-asteroid-collision
0741-cherry-pickup
0744-find-smallest-letter-greater-than-target
0792-binary-search
0875-koko-eating-bananas
0890-lemonade-change
0948-sort-an-array
0983-validate-stack-sequences
1011-capacity-to-ship-packages-within-d-days
1019-squares-of-a-sorted-array
1036-rotting-oranges
1056-capacity-to-ship-packages-within-d-days
1127-last-stone-weight
1231-replace-elements-with-greatest-element-on-right-side
1283-find-the-smallest-divisor-given-a-threshold
1319-unique-number-of-occurrences
1435-xor-queries-of-a-subarray
1496-lucky-numbers-in-a-matrix
1511-count-number-of-teams
1524-string-matching-in-an-array
1556-make-two-arrays-equal-by-reversing-subarrays
1605-minimum-number-of-days-to-make-m-bouquets
1635-number-of-good-pairs
1781-check-if-two-string-arrays-are-equivalent
1786-count-the-number-of-consistent-strings
1803-average-waiting-time
1878-check-if-array-is-sorted-and-rotated
2006-find-the-student-that-will-replace-the-chalk
2067-maximum-number-of-points-with-cost
2144-maximum-difference-between-increasing-elements
2155-find-missing-observations
2199-two-furthest-houses-with-different-colors
2255-minimum-swaps-to-group-all-1s-together-ii
2271-rearrange-array-elements-by-sign
2350-find-closest-number-to-zero
2727-number-of-senior-citizens
3235-minimum-cost-to-convert-string-i
3420-find-occurrences-of-an-element-in-an-array

Two Pointers

0011-container-with-most-water
0015-3sum
0031-next-permutation
0042-trapping-rain-water
0075-sort-colors
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0234-palindrome-linked-list
0283-move-zeroes
0295-find-median-from-data-stream
0349-intersection-of-two-arrays
0443-string-compression
0567-permutation-in-string
0647-palindromic-substrings
0908-middle-of-the-linked-list
1019-squares-of-a-sorted-array
2271-rearrange-array-elements-by-sign

Sorting

0015-3sum
0049-group-anagrams
0075-sort-colors
0169-majority-element
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0295-find-median-from-data-stream
0349-intersection-of-two-arrays
0451-sort-characters-by-frequency
0948-sort-an-array
1019-squares-of-a-sorted-array
1556-make-two-arrays-equal-by-reversing-subarrays

Simulation

0735-asteroid-collision
0983-validate-stack-sequences
1803-average-waiting-time
2006-find-the-student-that-will-replace-the-chalk
2155-find-missing-observations
2271-rearrange-array-elements-by-sign

Prefix Sum

0209-minimum-size-subarray-sum
0560-subarray-sum-equals-k
1435-xor-queries-of-a-subarray
2006-find-the-student-that-will-replace-the-chalk

Binary Search

0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0069-sqrtx
0074-search-a-2d-matrix
0081-search-in-rotated-sorted-array-ii
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0278-first-bad-version
0349-intersection-of-two-arrays
0540-single-element-in-a-sorted-array
0729-my-calendar-i
0744-find-smallest-letter-greater-than-target
0792-binary-search
0875-koko-eating-bananas
1011-capacity-to-ship-packages-within-d-days
1056-capacity-to-ship-packages-within-d-days
1283-find-the-smallest-divisor-given-a-threshold
1605-minimum-number-of-days-to-make-m-bouquets
2006-find-the-student-that-will-replace-the-chalk

Divide and Conquer

0169-majority-element
0190-reverse-bits
0948-sort-an-array

Counting

0169-majority-element
0229-majority-element-ii
0383-ransom-note
0451-sort-characters-by-frequency
1534-minimum-number-of-frogs-croaking
1635-number-of-good-pairs
1786-count-the-number-of-consistent-strings

Greedy

0011-container-with-most-water
0055-jump-game
0409-longest-palindrome
0890-lemonade-change
1903-largest-odd-number-in-string
2199-two-furthest-houses-with-different-colors

Dynamic Programming

0042-trapping-rain-water
0055-jump-game
0062-unique-paths
0070-climbing-stairs
0121-best-time-to-buy-and-sell-stock
0152-maximum-product-subarray
0279-perfect-squares
0647-palindromic-substrings
0650-2-keys-keyboard
0741-cherry-pickup
1013-fibonacci-number
1511-count-number-of-teams
2067-maximum-number-of-points-with-cost

String Matching

0796-rotate-string
0812-rotate-string
1524-string-matching-in-an-array

Math

0007-reverse-integer
0048-rotate-image
0062-unique-paths
0066-plus-one
0069-sqrtx
0070-climbing-stairs
0189-rotate-array
0204-count-primes
0263-ugly-number
0273-integer-to-english-words
0279-perfect-squares
0371-sum-of-two-integers
0650-2-keys-keyboard
1013-fibonacci-number
1635-number-of-good-pairs
1674-minimum-operations-to-make-array-equal
1903-largest-odd-number-in-string
2155-find-missing-observations

Enumeration

0204-count-primes

Number Theory

0204-count-primes

Union Find

0128-longest-consecutive-sequence

Stack

0020-valid-parentheses
0042-trapping-rain-water
0094-binary-tree-inorder-traversal
0143-reorder-list
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0735-asteroid-collision
0983-validate-stack-sequences
1021-remove-outermost-parentheses

Monotonic Stack

0042-trapping-rain-water

Matrix

0036-valid-sudoku
0048-rotate-image
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0741-cherry-pickup
1036-rotting-oranges
1496-lucky-numbers-in-a-matrix

Heap (Priority Queue)

0295-find-median-from-data-stream
0451-sort-characters-by-frequency
0948-sort-an-array
1127-last-stone-weight

Merge Sort

0948-sort-an-array

Bucket Sort

0451-sort-characters-by-frequency
0948-sort-an-array

Radix Sort

0948-sort-an-array

Counting Sort

0948-sort-an-array

Graph

0207-course-schedule
3235-minimum-cost-to-convert-string-i

Shortest Path

3235-minimum-cost-to-convert-string-i

Binary Indexed Tree

1511-count-number-of-teams

Linked List

0021-merge-two-sorted-lists
0083-remove-duplicates-from-sorted-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0206-reverse-linked-list
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0908-middle-of-the-linked-list

Recursion

0021-merge-two-sorted-lists
0143-reorder-list
0206-reverse-linked-list
0234-palindrome-linked-list
0273-integer-to-english-words
1013-fibonacci-number

Design

0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0295-find-median-from-data-stream
0729-my-calendar-i

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks

Tree

0094-binary-tree-inorder-traversal
0102-binary-tree-level-order-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal

Depth-First Search

0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0207-course-schedule

Binary Tree

0094-binary-tree-inorder-traversal
0102-binary-tree-level-order-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal

Breadth-First Search

0102-binary-tree-level-order-traversal
0207-course-schedule
0279-perfect-squares
1036-rotting-oranges

Data Stream

0295-find-median-from-data-stream

Memoization

0070-climbing-stairs
1013-fibonacci-number

Combinatorics

0062-unique-paths

Backtracking

0040-combination-sum-ii

Topological Sort

0207-course-schedule

Bit Manipulation

0190-reverse-bits
0260-single-number-iii
0371-sum-of-two-integers
1435-xor-queries-of-a-subarray
1786-count-the-number-of-consistent-strings

Segment Tree

0729-my-calendar-i

Ordered Set

0729-my-calendar-i

Interactive

0278-first-bad-version

Trie

0014-longest-common-prefix