Leetcode-solutions

Collection of LeetCode questions to ace the coding interview! - Created using LeetHub

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
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0039-combination-sum
0040-combination-sum-ii
0056-merge-intervals
0074-search-a-2d-matrix
0075-sort-colors
0081-search-in-rotated-sorted-array-ii
0088-merge-sorted-array
0090-subsets-ii
0118-pascals-triangle
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0204-count-primes
0217-contains-duplicate
0229-majority-element-ii
0240-search-a-2d-matrix-ii
0268-missing-number
0410-split-array-largest-sum
0448-find-all-numbers-disappeared-in-an-array
0493-reverse-pairs
0540-single-element-in-a-sorted-array
0907-koko-eating-bananas
0909-stone-game
0940-fruit-into-baskets
0952-word-subsets
1056-capacity-to-ship-packages-within-d-days
1364-tuple-with-same-product
1408-find-the-smallest-divisor-given-a-threshold
1421-find-numbers-with-even-number-of-digits
1478-maximum-number-of-events-that-can-be-attended
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1524-string-matching-in-an-array
1605-minimum-number-of-days-to-make-m-bouquets
1646-kth-missing-positive-number
1813-maximum-erasure-value
1878-check-if-array-is-sorted-and-rotated
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1995-finding-pairs-with-a-certain-sum
2047-find-a-peak-element-ii
2058-concatenation-of-array
2265-partition-array-according-to-given-pivot
2292-counting-words-with-a-given-prefix
2316-count-hills-and-valleys-in-an-array
2341-count-prefixes-of-a-given-string
2358-number-of-ways-to-split-array
2429-design-a-food-rating-system
2465-shifting-letters-ii
2533-bitwise-xor-of-all-pairings
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
3309-count-prefix-and-suffix-pairs-i
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3748-sort-matrix-by-diagonals
3788-maximum-unique-subarray-sum-after-deletion

Hash Table

0001-two-sum
0012-integer-to-roman
0013-roman-to-integer
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0205-isomorphic-strings
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0448-find-all-numbers-disappeared-in-an-array
0451-sort-characters-by-frequency
0940-fruit-into-baskets
0952-word-subsets
1264-maximum-number-of-words-you-can-type
1364-tuple-with-same-product
1502-construct-k-palindrome-strings
1813-maximum-erasure-value
1890-sum-of-beauty-of-all-substrings
1915-check-if-one-string-swap-can-make-strings-equal
1995-finding-pairs-with-a-certain-sum
2059-unique-length-3-palindromic-subsequences
2429-design-a-food-rating-system
2766-find-the-prefix-common-array-of-two-arrays
3455-minimum-length-of-string-after-operations
3788-maximum-unique-subarray-sum-after-deletion
3872-find-most-frequent-vowel-and-consonant

Sorting

0015-3sum
0016-3sum-closest
0018-4sum
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0148-sort-list
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0451-sort-characters-by-frequency
1478-maximum-number-of-events-that-can-be-attended
3748-sort-matrix-by-diagonals

Math

0002-add-two-numbers
0012-integer-to-roman
0013-roman-to-integer
0070-climbing-stairs
0204-count-primes
0268-missing-number
0326-power-of-three
0342-power-of-four
0909-stone-game
1421-find-numbers-with-even-number-of-digits
1448-maximum-69-number
1642-water-bottles
2032-largest-odd-number-in-string
3279-alice-and-bob-playing-flower-game
3462-vowels-game-in-a-string

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
0074-search-a-2d-matrix
0081-search-in-rotated-sorted-array-ii
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0240-search-a-2d-matrix-ii
0268-missing-number
0410-split-array-largest-sum
0493-reverse-pairs
0540-single-element-in-a-sorted-array
0907-koko-eating-bananas
1056-capacity-to-ship-packages-within-d-days
1408-find-the-smallest-divisor-given-a-threshold
1605-minimum-number-of-days-to-make-m-bouquets
1646-kth-missing-positive-number
2047-find-a-peak-element-ii

Bit Manipulation

0090-subsets-ii
0268-missing-number
0342-power-of-four
2059-unique-length-3-palindromic-subsequences
2323-minimum-bit-flips-to-convert-number
2509-minimize-xor
2533-bitwise-xor-of-all-pairings
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor

String

0005-longest-palindromic-substring
0008-string-to-integer-atoi
0010-regular-expression-matching
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0131-palindrome-partitioning
0151-reverse-words-in-a-string
0205-isomorphic-strings
0242-valid-anagram
0392-is-subsequence
0451-sort-characters-by-frequency
0812-rotate-string
0952-word-subsets
1078-remove-outermost-parentheses
1264-maximum-number-of-words-you-can-type
1502-construct-k-palindrome-strings
1524-string-matching-in-an-array
1537-maximum-score-after-splitting-a-string
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1737-maximum-nesting-depth-of-the-parentheses
1818-maximum-score-from-removing-substrings
1890-sum-of-beauty-of-all-substrings
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1915-check-if-one-string-swap-can-make-strings-equal
2032-largest-odd-number-in-string
2059-unique-length-3-palindromic-subsequences
2221-check-if-a-parentheses-string-can-be-valid
2292-counting-words-with-a-given-prefix
2341-count-prefixes-of-a-given-string
2346-largest-3-same-digit-number-in-string
2429-design-a-food-rating-system
2465-shifting-letters-ii
3309-count-prefix-and-suffix-pairs-i
3379-score-of-a-string
3396-valid-word
3455-minimum-length-of-string-after-operations
3462-vowels-game-in-a-string
3872-find-most-frequent-vowel-and-consonant

Prefix Sum

0410-split-array-largest-sum
1537-maximum-score-after-splitting-a-string
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
2059-unique-length-3-palindromic-subsequences
2358-number-of-ways-to-split-array
2465-shifting-letters-ii

Counting

0229-majority-element-ii
0451-sort-characters-by-frequency
1364-tuple-with-same-product
1502-construct-k-palindrome-strings
1890-sum-of-beauty-of-all-substrings
1915-check-if-one-string-swap-can-make-strings-equal
3455-minimum-length-of-string-after-operations
3872-find-most-frequent-vowel-and-consonant

String Matching

0812-rotate-string
1524-string-matching-in-an-array
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i

Trie

0014-longest-common-prefix
3309-count-prefix-and-suffix-pairs-i

Rolling Hash

3309-count-prefix-and-suffix-pairs-i

Hash Function

3309-count-prefix-and-suffix-pairs-i

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0061-rotate-list
0075-sort-colors
0088-merge-sorted-array
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0234-palindrome-linked-list
0392-is-subsequence
0908-middle-of-the-linked-list
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
2216-delete-the-middle-node-of-a-linked-list
2265-partition-array-according-to-given-pivot

Database

0185-department-top-three-salaries

Greedy

0011-container-with-most-water
0410-split-array-largest-sum
1448-maximum-69-number
1478-maximum-number-of-events-that-can-be-attended
1502-construct-k-palindrome-strings
1818-maximum-score-from-removing-substrings
2032-largest-odd-number-in-string
2221-check-if-a-parentheses-string-can-be-valid
2509-minimize-xor
3788-maximum-unique-subarray-sum-after-deletion

Stack

0234-palindrome-linked-list
1078-remove-outermost-parentheses
1737-maximum-nesting-depth-of-the-parentheses
1818-maximum-score-from-removing-substrings
2221-check-if-a-parentheses-string-can-be-valid

Brainteaser

2533-bitwise-xor-of-all-pairings
3462-vowels-game-in-a-string

Breadth-First Search

0107-binary-tree-level-order-traversal-ii
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid

Graph

1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid

Heap (Priority Queue)

0451-sort-characters-by-frequency
1478-maximum-number-of-events-that-can-be-attended
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2429-design-a-food-rating-system

Matrix

0074-search-a-2d-matrix
0240-search-a-2d-matrix-ii
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2047-find-a-peak-element-ii
3748-sort-matrix-by-diagonals

Shortest Path

1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid

Dynamic Programming

0005-longest-palindromic-substring
0010-regular-expression-matching
0070-climbing-stairs
0118-pascals-triangle
0131-palindrome-partitioning
0152-maximum-product-subarray
0392-is-subsequence
0410-split-array-largest-sum
0909-stone-game

Divide and Conquer

0004-median-of-two-sorted-arrays
0109-convert-sorted-list-to-binary-search-tree
0148-sort-list
0240-search-a-2d-matrix-ii
0493-reverse-pairs

Binary Indexed Tree

0493-reverse-pairs

Segment Tree

0493-reverse-pairs

Merge Sort

0148-sort-list
0493-reverse-pairs

Ordered Set

0493-reverse-pairs
2429-design-a-food-rating-system

Simulation

1642-water-bottles
2058-concatenation-of-array
2265-partition-array-according-to-given-pivot

Linked List

0002-add-two-numbers
0025-reverse-nodes-in-k-group
0061-rotate-list
0109-convert-sorted-list-to-binary-search-tree
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0160-intersection-of-two-linked-lists
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0328-odd-even-linked-list
0908-middle-of-the-linked-list
2216-delete-the-middle-node-of-a-linked-list

Tree

0107-binary-tree-level-order-traversal-ii
0109-convert-sorted-list-to-binary-search-tree
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii

Binary Search Tree

0109-convert-sorted-list-to-binary-search-tree

Binary Tree

0107-binary-tree-level-order-traversal-ii
0109-convert-sorted-list-to-binary-search-tree
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii

Design

1995-finding-pairs-with-a-certain-sum
2429-design-a-food-rating-system

Sliding Window

0940-fruit-into-baskets
1813-maximum-erasure-value

Memoization

0070-climbing-stairs

Bucket Sort

0451-sort-characters-by-frequency

Recursion

0002-add-two-numbers
0010-regular-expression-matching
0025-reverse-nodes-in-k-group
0234-palindrome-linked-list
0326-power-of-three
0342-power-of-four

Depth-First Search

0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii

Game Theory

0909-stone-game
3462-vowels-game-in-a-string

Backtracking

0039-combination-sum
0040-combination-sum-ii
0052-n-queens-ii
0090-subsets-ii
0131-palindrome-partitioning

Enumeration

0204-count-primes

Number Theory

0204-count-primes