leetcode

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

LeetCode Topics

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
0014-longest-common-prefix
0015-3sum
0016-3sum-closest
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
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
0039-combination-sum
0042-trapping-rain-water
0045-jump-game-ii
0048-rotate-image
0049-group-anagrams
0051-n-queens
0053-maximum-subarray
0054-spiral-matrix
0055-jump-game
0063-unique-paths-ii
0066-plus-one
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0075-sort-colors
0081-search-in-rotated-sorted-array-ii
0088-merge-sorted-array
0118-pascals-triangle
0119-pascals-triangle-ii
0120-triangle
0121-best-time-to-buy-and-sell-stock
0136-single-number
0137-single-number-ii
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
0220-contains-duplicate-iii
0239-sliding-window-maximum
0268-missing-number
0283-move-zeroes
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0414-third-maximum-number
0525-contiguous-array
0560-subarray-sum-equals-k
0628-maximum-product-of-three-numbers
0704-binary-search
0717-1-bit-and-2-bit-characters
0718-maximum-length-of-repeated-subarray
0937-reorder-data-in-log-files
0974-subarray-sums-divisible-by-k
0977-squares-of-a-sorted-array
1029-two-city-scheduling
1037-valid-boomerang
1232-check-if-it-is-a-straight-line
1268-search-suggestions-system
1464-maximum-product-of-two-elements-in-an-array
1732-find-the-highest-altitude
1967-number-of-strings-that-appear-as-substrings-in-word
1979-find-greatest-common-divisor-of-array
1998-gcd-sort-of-an-array
2185-counting-words-with-a-given-prefix
2706-buy-two-chocolates
3411-maximum-subarray-with-equal-products

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0030-substring-with-concatenation-of-all-words
0036-valid-sudoku
0049-group-anagrams
0073-set-matrix-zeroes
0076-minimum-window-substring
0169-majority-element
0187-repeated-dna-sequences
0202-happy-number
0205-isomorphic-strings
0217-contains-duplicate
0219-contains-duplicate-ii
0242-valid-anagram
0268-missing-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0525-contiguous-array
0560-subarray-sum-equals-k
0974-subarray-sums-divisible-by-k
1189-maximum-number-of-balloons

Divide and Conquer

0004-median-of-two-sorted-arrays
0053-maximum-subarray
0169-majority-element

Sorting

0015-3sum
0016-3sum-closest
0018-4sum
0049-group-anagrams
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0217-contains-duplicate
0220-contains-duplicate-iii
0242-valid-anagram
0268-missing-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0414-third-maximum-number
0628-maximum-product-of-three-numbers
0937-reorder-data-in-log-files
0977-squares-of-a-sorted-array
1029-two-city-scheduling
1268-search-suggestions-system
1464-maximum-product-of-two-elements-in-an-array
1998-gcd-sort-of-an-array
2706-buy-two-chocolates

Counting

0169-majority-element
1189-maximum-number-of-balloons

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0029-divide-two-integers
0043-multiply-strings
0048-rotate-image
0050-powx-n
0062-unique-paths
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0089-gray-code
0168-excel-sheet-column-title
0171-excel-sheet-column-number
0189-rotate-array
0202-happy-number
0204-count-primes
0223-rectangle-area
0224-basic-calculator
0227-basic-calculator-ii
0231-power-of-two
0233-number-of-digit-one
0258-add-digits
0263-ugly-number
0268-missing-number
0326-power-of-three
0371-sum-of-two-integers
0412-fizz-buzz
0628-maximum-product-of-three-numbers
0866-prime-palindrome
1025-divisor-game
1037-valid-boomerang
1154-day-of-the-year
1185-day-of-the-week
1232-check-if-it-is-a-straight-line
1979-find-greatest-common-divisor-of-array
1998-gcd-sort-of-an-array
2235-add-two-integers
2413-smallest-even-multiple
2427-number-of-common-factors
3411-maximum-subarray-with-equal-products
3658-gcd-of-odd-and-even-sums

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0006-zigzag-conversion
0008-string-to-integer-atoi
0010-regular-expression-matching
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0020-valid-parentheses
0022-generate-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0030-substring-with-concatenation-of-all-words
0032-longest-valid-parentheses
0043-multiply-strings
0044-wildcard-matching
0049-group-anagrams
0058-length-of-last-word
0065-valid-number
0067-add-binary
0076-minimum-window-substring
0125-valid-palindrome
0151-reverse-words-in-a-string
0168-excel-sheet-column-title
0171-excel-sheet-column-number
0187-repeated-dna-sequences
0205-isomorphic-strings
0224-basic-calculator
0227-basic-calculator-ii
0242-valid-anagram
0344-reverse-string
0392-is-subsequence
0412-fizz-buzz
0917-reverse-only-letters
0937-reorder-data-in-log-files
1154-day-of-the-year
1189-maximum-number-of-balloons
1268-search-suggestions-system
1967-number-of-strings-that-appear-as-substrings-in-word
2000-reverse-prefix-of-word
2185-counting-words-with-a-given-prefix
3794-reverse-string-prefix

Stack

0020-valid-parentheses
0032-longest-valid-parentheses
0042-trapping-rain-water
0224-basic-calculator
0227-basic-calculator-ii
2000-reverse-prefix-of-word

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
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
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0202-happy-number
0283-move-zeroes
0344-reverse-string
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0392-is-subsequence
0917-reverse-only-letters
0977-squares-of-a-sorted-array
2000-reverse-prefix-of-word
3794-reverse-string-prefix

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
2185-counting-words-with-a-given-prefix

Bit Manipulation

0029-divide-two-integers
0067-add-binary
0089-gray-code
0136-single-number
0137-single-number-ii
0187-repeated-dna-sequences
0231-power-of-two
0268-missing-number
0371-sum-of-two-integers
2220-minimum-bit-flips-to-convert-number

Simulation

0043-multiply-strings
0054-spiral-matrix
0067-add-binary
0258-add-digits
0412-fizz-buzz

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
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
0268-missing-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0704-binary-search
0718-maximum-length-of-repeated-subarray
1268-search-suggestions-system

Dynamic Programming

0005-longest-palindromic-substring
0010-regular-expression-matching
0022-generate-parentheses
0032-longest-valid-parentheses
0042-trapping-rain-water
0044-wildcard-matching
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0062-unique-paths
0063-unique-paths-ii
0070-climbing-stairs
0118-pascals-triangle
0119-pascals-triangle-ii
0120-triangle
0121-best-time-to-buy-and-sell-stock
0152-maximum-product-subarray
0233-number-of-digit-one
0392-is-subsequence
0718-maximum-length-of-repeated-subarray
1025-divisor-game

Memoization

0070-climbing-stairs

Greedy

0011-container-with-most-water
0044-wildcard-matching
0045-jump-game-ii
0055-jump-game
1029-two-city-scheduling
2706-buy-two-chocolates

Linked List

0002-add-two-numbers
0021-merge-two-sorted-lists

Recursion

0002-add-two-numbers
0010-regular-expression-matching
0021-merge-two-sorted-lists
0044-wildcard-matching
0050-powx-n
0224-basic-calculator
0231-power-of-two
0233-number-of-digit-one
0326-power-of-three

Trie

0014-longest-common-prefix
1268-search-suggestions-system

Matrix

0036-valid-sudoku
0048-rotate-image
0054-spiral-matrix
0063-unique-paths-ii
0073-set-matrix-zeroes
0074-search-a-2d-matrix

Database

0181-employees-earning-more-than-their-managers

Sliding Window

0003-longest-substring-without-repeating-characters
0030-substring-with-concatenation-of-all-words
0076-minimum-window-substring
0187-repeated-dna-sequences
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0220-contains-duplicate-iii
0239-sliding-window-maximum
0718-maximum-length-of-repeated-subarray
3411-maximum-subarray-with-equal-products

Brainteaser

1025-divisor-game

Game Theory

1025-divisor-game

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0039-combination-sum
0051-n-queens
0089-gray-code

Geometry

0223-rectangle-area
1037-valid-boomerang
1232-check-if-it-is-a-straight-line

Queue

0239-sliding-window-maximum

Heap (Priority Queue)

0239-sliding-window-maximum
1268-search-suggestions-system
1464-maximum-product-of-two-elements-in-an-array

Monotonic Queue

0239-sliding-window-maximum

Rolling Hash

0187-repeated-dna-sequences
0718-maximum-length-of-repeated-subarray

Hash Function

0187-repeated-dna-sequences
0718-maximum-length-of-repeated-subarray

Prefix Sum

0209-minimum-size-subarray-sum
0525-contiguous-array
0560-subarray-sum-equals-k
0974-subarray-sums-divisible-by-k
1732-find-the-highest-altitude

Number Theory

0204-count-primes
0258-add-digits
0866-prime-palindrome
1979-find-greatest-common-divisor-of-array
1998-gcd-sort-of-an-array
2413-smallest-even-multiple
2427-number-of-common-factors
3411-maximum-subarray-with-equal-products
3658-gcd-of-odd-and-even-sums

Monotonic Stack

0042-trapping-rain-water

Bucket Sort

0220-contains-duplicate-iii

Ordered Set

0220-contains-duplicate-iii

Combinatorics

0062-unique-paths

Union-Find

1998-gcd-sort-of-an-array

Enumeration

0204-count-primes
2427-number-of-common-factors
3411-maximum-subarray-with-equal-products