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
0014-longest-common-prefix
0026-remove-duplicates-from-sorted-array
0027-remove-element
0036-valid-sudoku
0041-first-missing-positive
0048-rotate-image
0066-plus-one
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0136-single-number
0150-evaluate-reverse-polish-notation
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0204-count-primes
0217-contains-duplicate
0268-missing-number
0414-third-maximum-number
0448-find-all-numbers-disappeared-in-an-array
0485-max-consecutive-ones
0506-relative-ranks
0561-array-partition
0575-distribute-candies
0645-set-mismatch
0717-1-bit-and-2-bit-characters
0747-largest-number-at-least-twice-of-others
0898-transpose-matrix
0905-sort-array-by-parity
0977-squares-of-a-sorted-array
1018-binary-prefix-divisible-by-5
1346-check-if-n-and-its-double-exist
1350-remove-sub-folders-from-the-filesystem
1351-count-negative-numbers-in-a-sorted-matrix
1365-how-many-numbers-are-smaller-than-the-current-number
1426-find-n-unique-integers-sum-up-to-zero
1441-build-an-array-with-stack-operations
1470-shuffle-the-array
1480-running-sum-of-1d-array
1528-shuffle-string
1539-kth-missing-positive-number
1550-three-consecutive-odds
1586-longest-subarray-of-1s-after-deleting-one-element
1608-special-array-with-x-elements-greater-than-or-equal-x
1619-mean-of-array-after-removing-some-elements
1628-count-submatrices-with-all-ones
1646-kth-missing-positive-number
1732-find-the-highest-altitude
1813-maximum-erasure-value
1816-truncate-sentence
1833-maximum-ice-cream-bars
1846-maximum-element-after-decreasing-and-rearranging
1877-minimize-maximum-pair-sum-in-array
1893-check-if-all-the-integers-in-a-range-are-covered
1929-concatenation-of-array
1967-number-of-strings-that-appear-as-substrings-in-word
2020-remove-one-element-to-make-the-array-strictly-increasing
2032-two-out-of-three
2057-smallest-index-with-equal-value
2058-concatenation-of-array
2079-delete-duplicate-folders-in-system
2108-find-first-palindromic-string-in-the-array
2137-final-value-of-variable-after-performing-operations
2154-keep-multiplying-found-values-by-two
2215-find-the-difference-of-two-arrays
2239-find-closest-number-to-zero
2267-minimum-difference-in-sums-after-removal-of-elements
2316-count-hills-and-valleys-in-an-array
2395-find-subarrays-with-equal-sum
2400-minimum-score-after-removals-on-a-tree
2441-largest-positive-integer-that-exists-with-its-negative
2496-maximum-value-of-a-string-in-an-array
2503-longest-subarray-with-maximum-bitwise-and
2540-minimum-common-value
2553-separate-the-digits-in-an-array
2574-left-and-right-sum-differences
2586-count-the-number-of-vowel-strings-in-range
2694-find-the-maximum-divisibility-score
2798-number-of-employees-who-met-the-target
2956-find-common-elements-between-two-arrays
2996-smallest-missing-integer-greater-than-sequential-prefix-sum
3038-maximum-number-of-operations-with-the-same-score-i
3074-apple-redistribution-into-boxes
3190-find-minimum-operations-to-make-all-elements-divisible-by-three
3285-find-indices-of-stable-mountains
3300-minimum-element-after-replacement-with-digit-sum
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3512-minimum-operations-to-make-array-sum-divisible-by-k
3684-maximize-sum-of-at-most-k-distinct-elements
3689-maximum-total-subarray-value-i
3701-compute-alternating-sum
3718-smallest-missing-multiple-of-k
3788-maximum-unique-subarray-sum-after-deletion
3789-maximize-subarrays-after-removing-one-conflicting-pair
3838-weighted-word-mapping

Hash Table

0001-two-sum
0036-valid-sudoku
0041-first-missing-positive
0169-majority-element
0202-happy-number
0217-contains-duplicate
0242-valid-anagram
0268-missing-number
0389-find-the-difference
0448-find-all-numbers-disappeared-in-an-array
0575-distribute-candies
0645-set-mismatch
1015-smallest-integer-divisible-by-k
1346-check-if-n-and-its-double-exist
1365-how-many-numbers-are-smaller-than-the-current-number
1813-maximum-erasure-value
1893-check-if-all-the-integers-in-a-range-are-covered
2032-two-out-of-three
2079-delete-duplicate-folders-in-system
2154-keep-multiplying-found-values-by-two
2215-find-the-difference-of-two-arrays
2395-find-subarrays-with-equal-sum
2441-largest-positive-integer-that-exists-with-its-negative
2540-minimum-common-value
2956-find-common-elements-between-two-arrays
2996-smallest-missing-integer-greater-than-sequential-prefix-sum
3684-maximize-sum-of-at-most-k-distinct-elements
3718-smallest-missing-multiple-of-k
3788-maximum-unique-subarray-sum-after-deletion

Linked List

0002-add-two-numbers
0206-reverse-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer

Math

0002-add-two-numbers
0009-palindrome-number
0029-divide-two-integers
0043-multiply-strings
0048-rotate-image
0066-plus-one
0069-sqrtx
0070-climbing-stairs
0150-evaluate-reverse-polish-notation
0171-excel-sheet-column-number
0202-happy-number
0204-count-primes
0231-power-of-two
0258-add-digits
0268-missing-number
0326-power-of-three
0342-power-of-four
0412-fizz-buzz
0504-base-7
0762-prime-number-of-set-bits-in-binary-representation
1015-smallest-integer-divisible-by-k
1154-day-of-the-year
1317-convert-integer-to-the-sum-of-two-no-zero-integers
1411-convert-binary-number-in-a-linked-list-to-integer
1426-find-n-unique-integers-sum-up-to-zero
1448-maximum-69-number
1523-count-odd-numbers-in-an-interval-range
1925-count-square-sum-triples
1952-three-divisors
2119-a-number-after-a-double-reversal
2235-add-two-integers
2288-count-operations-to-obtain-zero
2396-strictly-palindromic-number
2520-count-the-digits-that-divide-a-number
2651-calculate-delayed-arrival-time
2652-sum-multiples
2769-find-the-maximum-achievable-number
3190-find-minimum-operations-to-make-all-elements-divisible-by-three
3227-vowels-game-in-a-string
3279-alice-and-bob-playing-flower-game
3300-minimum-element-after-replacement-with-digit-sum
3345-smallest-divisible-digit-product-i
3492-maximum-containers-on-a-ship
3512-minimum-operations-to-make-array-sum-divisible-by-k
3536-maximum-product-of-two-digits
3622-check-divisibility-by-digit-sum-and-product
3658-gcd-of-odd-and-even-sums
3676-smallest-number-with-all-set-bits
3783-mirror-distance-of-an-integer
3830-find-closest-person
3871-count-commas-in-range-ii

String

0014-longest-common-prefix
0020-valid-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0043-multiply-strings
0058-length-of-last-word
0171-excel-sheet-column-number
0242-valid-anagram
0344-reverse-string
0389-find-the-difference
0392-is-subsequence
0412-fizz-buzz
0434-number-of-segments-in-a-string
0504-base-7
0551-student-attendance-record-i
0796-rotate-string
0844-backspace-string-compare
1047-remove-all-adjacent-duplicates-in-string
1154-day-of-the-year
1302-delete-characters-to-make-fancy-string
1350-remove-sub-folders-from-the-filesystem
1446-consecutive-characters
1528-shuffle-string
1784-check-if-binary-string-has-at-most-one-segment-of-ones
1816-truncate-sentence
1818-maximum-score-from-removing-substrings
1823-determine-if-string-halves-are-alike
1967-number-of-strings-that-appear-as-substrings-in-word
2000-reverse-prefix-of-word
2079-delete-duplicate-folders-in-system
2108-find-first-palindromic-string-in-the-array
2137-final-value-of-variable-after-performing-operations
2264-largest-3-same-digit-number-in-string
2379-minimum-recolors-to-get-k-consecutive-black-blocks
2390-removing-stars-from-a-string
2496-maximum-value-of-a-string-in-an-array
2586-count-the-number-of-vowel-strings-in-range
2839-check-if-strings-can-be-made-equal-with-operations-i
2999-check-if-strings-can-be-made-equal-with-operations-i
3168-minimum-number-of-chairs-in-a-waiting-room
3227-vowels-game-in-a-string
3396-valid-word
3838-weighted-word-mapping

Trie

0014-longest-common-prefix
1350-remove-sub-folders-from-the-filesystem
2079-delete-duplicate-folders-in-system

Dynamic Programming

0070-climbing-stairs
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0338-counting-bits
0392-is-subsequence
1586-longest-subarray-of-1s-after-deleting-one-element
1628-count-submatrices-with-all-ones
2267-minimum-difference-in-sums-after-removal-of-elements
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii

Heap (Priority Queue)

0506-relative-ranks
2267-minimum-difference-in-sums-after-removal-of-elements

Depth-First Search

1350-remove-sub-folders-from-the-filesystem
2400-minimum-score-after-removals-on-a-tree

Hash Function

2079-delete-duplicate-folders-in-system

Sliding Window

1586-longest-subarray-of-1s-after-deleting-one-element
1813-maximum-erasure-value
2379-minimum-recolors-to-get-k-consecutive-black-blocks

Stack

0020-valid-parentheses
0150-evaluate-reverse-polish-notation
0844-backspace-string-compare
1047-remove-all-adjacent-duplicates-in-string
1441-build-an-array-with-stack-operations
1628-count-submatrices-with-all-ones
1818-maximum-score-from-removing-substrings
2000-reverse-prefix-of-word
2390-removing-stars-from-a-string

Greedy

0561-array-partition
1448-maximum-69-number
1818-maximum-score-from-removing-substrings
1833-maximum-ice-cream-bars
1846-maximum-element-after-decreasing-and-rearranging
1877-minimize-maximum-pair-sum-in-array
3074-apple-redistribution-into-boxes
3684-maximize-sum-of-at-most-k-distinct-elements
3689-maximum-total-subarray-value-i
3788-maximum-unique-subarray-sum-after-deletion

Bit Manipulation

0029-divide-two-integers
0136-single-number
0190-reverse-bits
0191-number-of-1-bits
0231-power-of-two
0268-missing-number
0338-counting-bits
0342-power-of-four
0389-find-the-difference
0645-set-mismatch
0693-binary-number-with-alternating-bits
0762-prime-number-of-set-bits-in-binary-representation
1009-complement-of-base-10-integer
1018-binary-prefix-divisible-by-5
2032-two-out-of-three
2400-minimum-score-after-removals-on-a-tree
2503-longest-subarray-with-maximum-bitwise-and
3676-smallest-number-with-all-set-bits

Tree

2400-minimum-score-after-removals-on-a-tree

Segment Tree

3789-maximize-subarrays-after-removing-one-conflicting-pair

Enumeration

0204-count-primes
1925-count-square-sum-triples
1952-three-divisors
3345-smallest-divisible-digit-product-i
3789-maximize-subarrays-after-removing-one-conflicting-pair

Prefix Sum

1480-running-sum-of-1d-array
1732-find-the-highest-altitude
1893-check-if-all-the-integers-in-a-range-are-covered
2574-left-and-right-sum-differences
3789-maximize-subarrays-after-removing-one-conflicting-pair

Brainteaser

2396-strictly-palindromic-number
2503-longest-subarray-with-maximum-bitwise-and
3227-vowels-game-in-a-string

Simulation

0043-multiply-strings
0258-add-digits
0412-fizz-buzz
0844-backspace-string-compare
0898-transpose-matrix
1441-build-an-array-with-stack-operations
1929-concatenation-of-array
2058-concatenation-of-array
2137-final-value-of-variable-after-performing-operations
2154-keep-multiplying-found-values-by-two
2288-count-operations-to-obtain-zero
2390-removing-stars-from-a-string
2553-separate-the-digits-in-an-array
3038-maximum-number-of-operations-with-the-same-score-i
3168-minimum-number-of-chairs-in-a-waiting-room
3701-compute-alternating-sum
3838-weighted-word-mapping

Recursion

0002-add-two-numbers
0206-reverse-linked-list
0231-power-of-two
0326-power-of-three
0342-power-of-four

Matrix

0036-valid-sudoku
0048-rotate-image
0898-transpose-matrix
1351-count-negative-numbers-in-a-sorted-matrix
1628-count-submatrices-with-all-ones

Monotonic Stack

1628-count-submatrices-with-all-ones

Binary Search

0004-median-of-two-sorted-arrays
0069-sqrtx
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0268-missing-number
0278-first-bad-version
1346-check-if-n-and-its-double-exist
1351-count-negative-numbers-in-a-sorted-matrix
1539-kth-missing-positive-number
1608-special-array-with-x-elements-greater-than-or-equal-x
1646-kth-missing-positive-number
2540-minimum-common-value

Database

0175-combine-two-tables
1136-actors-and-directors-who-cooperated-at-least-three-times
1517-find-users-with-valid-e-mails

Two Pointers

0026-remove-duplicates-from-sorted-array
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0167-two-sum-ii-input-array-is-sorted
0202-happy-number
0344-reverse-string
0392-is-subsequence
0844-backspace-string-compare
0905-sort-array-by-parity
0977-squares-of-a-sorted-array
1346-check-if-n-and-its-double-exist
1877-minimize-maximum-pair-sum-in-array
2000-reverse-prefix-of-word
2108-find-first-palindromic-string-in-the-array
2396-strictly-palindromic-number
2441-largest-positive-integer-that-exists-with-its-negative
2540-minimum-common-value

Sorting

0169-majority-element
0217-contains-duplicate
0242-valid-anagram
0268-missing-number
0389-find-the-difference
0414-third-maximum-number
0506-relative-ranks
0561-array-partition
0645-set-mismatch
0747-largest-number-at-least-twice-of-others
0905-sort-array-by-parity
0977-squares-of-a-sorted-array
1346-check-if-n-and-its-double-exist
1365-how-many-numbers-are-smaller-than-the-current-number
1608-special-array-with-x-elements-greater-than-or-equal-x
1619-mean-of-array-after-removing-some-elements
1833-maximum-ice-cream-bars
1846-maximum-element-after-decreasing-and-rearranging
1877-minimize-maximum-pair-sum-in-array
2154-keep-multiplying-found-values-by-two
2441-largest-positive-integer-that-exists-with-its-negative
2996-smallest-missing-integer-greater-than-sequential-prefix-sum
3074-apple-redistribution-into-boxes
3536-maximum-product-of-two-digits
3684-maximize-sum-of-at-most-k-distinct-elements

Counting

0169-majority-element
1823-determine-if-string-halves-are-alike
2586-count-the-number-of-vowel-strings-in-range

Divide and Conquer

0004-median-of-two-sorted-arrays
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
0796-rotate-string

Number Theory

0204-count-primes
0258-add-digits
1952-three-divisors
3658-gcd-of-odd-and-even-sums

Counting Sort

0561-array-partition
1365-how-many-numbers-are-smaller-than-the-current-number
1833-maximum-ice-cream-bars

Game Theory

3227-vowels-game-in-a-string

Memoization

0070-climbing-stairs

Interactive

0278-first-bad-version