Leetcode

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

LeetCode Topics

String

0043-multiply-strings
0049-group-anagrams
0058-length-of-last-word
0067-add-binary
0072-edit-distance
0151-reverse-words-in-a-string
0165-compare-version-numbers
0345-reverse-vowels-of-a-string
0387-first-unique-character-in-a-string
0412-fizz-buzz
0449-serialize-and-deserialize-bst
0583-delete-operation-for-two-strings
1205-defanging-an-ip-address
1250-longest-common-subsequence
1302-delete-characters-to-make-fancy-string
1353-find-resultant-array-after-removing-anagrams
1786-count-the-number-of-consistent-strings
1915-check-if-one-string-swap-can-make-strings-equal
2076-sum-of-digits-of-string-after-convert
2235-capitalize-the-title
2727-number-of-senior-citizens
3174-minimum-number-of-changes-to-make-binary-string-beautiful

Math

0043-multiply-strings
0048-rotate-image
0050-powx-n
0062-unique-paths
0066-plus-one
0067-add-binary
0069-sqrtx
0150-evaluate-reverse-polish-notation
0189-rotate-array
0202-happy-number
0231-power-of-two
0233-number-of-digit-one
0263-ugly-number
0268-missing-number
0292-nim-game
0326-power-of-three
0342-power-of-four
0367-valid-perfect-square
0412-fizz-buzz
0453-minimum-moves-to-equal-array-elements
0628-maximum-product-of-three-numbers
1444-number-of-steps-to-reduce-a-number-to-zero
1610-xor-operation-in-an-array
1635-number-of-good-pairs
1693-sum-of-all-odd-length-subarrays
1806-count-of-matches-in-tournament
1993-sum-of-all-subset-xor-totals
2155-find-missing-observations
2264-minimum-sum-of-four-digit-number-after-splitting-digits
2481-strictly-palindromic-number
2571-find-the-pivot-integer
2608-count-the-digits-that-divide-a-number
2624-difference-between-element-sum-and-digit-sum-of-an-array
2748-calculate-delayed-arrival-time
2752-sum-multiples
2812-find-the-maximum-achievable-number
3172-divisible-and-non-divisible-sums-difference
3371-harshad-number
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3515-find-if-digit-game-can-be-won

Binary Search

0004-median-of-two-sorted-arrays
0034-find-first-and-last-position-of-element-in-sorted-array
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
0268-missing-number
0287-find-the-duplicate-number
0367-valid-perfect-square
0882-peak-index-in-a-mountain-array
1476-count-negative-numbers-in-a-sorted-matrix
2006-find-the-student-that-will-replace-the-chalk
2614-maximum-count-of-positive-integer-and-negative-integer
2917-count-pairs-whose-sum-is-less-than-target

Hash Table

0001-two-sum
0041-first-missing-positive
0049-group-anagrams
0169-majority-element
0202-happy-number
0217-contains-duplicate
0268-missing-number
0387-first-unique-character-in-a-string
1353-find-resultant-array-after-removing-anagrams
1482-how-many-numbers-are-smaller-than-the-current-number
1635-number-of-good-pairs
1786-count-the-number-of-consistent-strings
1915-check-if-one-string-swap-can-make-strings-equal
3421-count-pairs-that-form-a-complete-day-i

Queue

0387-first-unique-character-in-a-string

Counting

0169-majority-element
0387-first-unique-character-in-a-string
1635-number-of-good-pairs
1786-count-the-number-of-consistent-strings
1915-check-if-one-string-swap-can-make-strings-equal
2614-maximum-count-of-positive-integer-and-negative-integer
3421-count-pairs-that-form-a-complete-day-i

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
0026-remove-duplicates-from-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0041-first-missing-positive
0048-rotate-image
0049-group-anagrams
0053-maximum-subarray
0055-jump-game
0063-unique-paths-ii
0064-minimum-path-sum
0066-plus-one
0074-search-a-2d-matrix
0075-sort-colors
0081-search-in-rotated-sorted-array-ii
0088-merge-sorted-array
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0135-candy
0136-single-number
0137-single-number-ii
0150-evaluate-reverse-polish-notation
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
0198-house-robber
0217-contains-duplicate
0268-missing-number
0274-h-index
0283-move-zeroes
0287-find-the-duplicate-number
0453-minimum-moves-to-equal-array-elements
0485-max-consecutive-ones
0628-maximum-product-of-three-numbers
0643-maximum-average-subarray-i
0724-find-pivot-index
0882-peak-index-in-a-mountain-array
0898-transpose-matrix
0948-sort-an-array
1353-find-resultant-array-after-removing-anagrams
1476-count-negative-numbers-in-a-sorted-matrix
1482-how-many-numbers-are-smaller-than-the-current-number
1574-maximum-product-of-two-elements-in-an-array
1635-number-of-good-pairs
1693-sum-of-all-odd-length-subarrays
1786-count-the-number-of-consistent-strings
1791-richest-customer-wealth
1849-maximum-absolute-sum-of-any-subarray
1878-check-if-array-is-sorted-and-rotated
1927-maximum-ascending-subarray-sum
1975-minimum-distance-to-the-target-element
1993-sum-of-all-subset-xor-totals
2006-find-the-student-that-will-replace-the-chalk
2155-find-missing-observations
2614-maximum-count-of-positive-integer-and-negative-integer
2624-difference-between-element-sum-and-digit-sum-of-an-array
2727-number-of-senior-citizens
2917-count-pairs-whose-sum-is-less-than-target
3397-find-the-integer-added-to-array-i
3421-count-pairs-that-form-a-complete-day-i
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3515-find-if-digit-game-can-be-won

Two Pointers

0011-container-with-most-water
0026-remove-duplicates-from-sorted-array
0075-sort-colors
0088-merge-sorted-array
0143-reorder-list
0151-reverse-words-in-a-string
0165-compare-version-numbers
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0202-happy-number
0283-move-zeroes
0287-find-the-duplicate-number
0345-reverse-vowels-of-a-string
2216-delete-the-middle-node-of-a-linked-list
2481-strictly-palindromic-number
2917-count-pairs-whose-sum-is-less-than-target

Sorting

0049-group-anagrams
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0217-contains-duplicate
0268-missing-number
0274-h-index
0628-maximum-product-of-three-numbers
0948-sort-an-array
1353-find-resultant-array-after-removing-anagrams
1482-how-many-numbers-are-smaller-than-the-current-number
1574-maximum-product-of-two-elements-in-an-array
2264-minimum-sum-of-four-digit-number-after-splitting-digits
2917-count-pairs-whose-sum-is-less-than-target

Brainteaser

0292-nim-game
2481-strictly-palindromic-number

Backtracking

1993-sum-of-all-subset-xor-totals

Bit Manipulation

0067-add-binary
0136-single-number
0137-single-number-ii
0231-power-of-two
0268-missing-number
0287-find-the-duplicate-number
0342-power-of-four
0476-number-complement
1444-number-of-steps-to-reduce-a-number-to-zero
1610-xor-operation-in-an-array
1786-count-the-number-of-consistent-strings
1993-sum-of-all-subset-xor-totals

Combinatorics

0062-unique-paths
1993-sum-of-all-subset-xor-totals

Enumeration

1993-sum-of-all-subset-xor-totals

Simulation

0043-multiply-strings
0067-add-binary
0412-fizz-buzz
0898-transpose-matrix
1806-count-of-matches-in-tournament
2006-find-the-student-that-will-replace-the-chalk
2076-sum-of-digits-of-string-after-convert
2155-find-missing-observations

Recursion

0050-powx-n
0143-reorder-list
0231-power-of-two
0233-number-of-digit-one
0326-power-of-three
0342-power-of-four

Prefix Sum

0724-find-pivot-index
1693-sum-of-all-odd-length-subarrays
2006-find-the-student-that-will-replace-the-chalk
2571-find-the-pivot-integer

Divide and Conquer

0004-median-of-two-sorted-arrays
0053-maximum-subarray
0169-majority-element
0948-sort-an-array

Greedy

0011-container-with-most-water
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0135-candy
2264-minimum-sum-of-four-digit-number-after-splitting-digits

Dynamic Programming

0053-maximum-subarray
0055-jump-game
0062-unique-paths
0063-unique-paths-ii
0064-minimum-path-sum
0072-edit-distance
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0152-maximum-product-subarray
0198-house-robber
0233-number-of-digit-one
0583-delete-operation-for-two-strings
0629-k-inverse-pairs-array
1250-longest-common-subsequence
1849-maximum-absolute-sum-of-any-subarray

Heap (Priority Queue)

0948-sort-an-array
1574-maximum-product-of-two-elements-in-an-array

Matrix

0048-rotate-image
0063-unique-paths-ii
0064-minimum-path-sum
0074-search-a-2d-matrix
0898-transpose-matrix
1476-count-negative-numbers-in-a-sorted-matrix
1791-richest-customer-wealth

Merge Sort

0948-sort-an-array

Bucket Sort

0948-sort-an-array

Radix Sort

0948-sort-an-array

Counting Sort

0274-h-index
0948-sort-an-array
1482-how-many-numbers-are-smaller-than-the-current-number

Game Theory

0292-nim-game

Stack

0094-binary-tree-inorder-traversal
0143-reorder-list
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0150-evaluate-reverse-polish-notation
0775-n-ary-tree-preorder-traversal
0776-n-ary-tree-postorder-traversal

Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0102-binary-tree-level-order-traversal
0107-binary-tree-level-order-traversal-ii
0112-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0449-serialize-and-deserialize-bst
0764-n-ary-tree-level-order-traversal
0774-maximum-depth-of-n-ary-tree
0775-n-ary-tree-preorder-traversal
0776-n-ary-tree-postorder-traversal
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree

Breadth-First Search

0100-same-tree
0102-binary-tree-level-order-traversal
0107-binary-tree-level-order-traversal-ii
0112-path-sum
0199-binary-tree-right-side-view
0449-serialize-and-deserialize-bst
0764-n-ary-tree-level-order-traversal
0774-maximum-depth-of-n-ary-tree

Binary Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0102-binary-tree-level-order-traversal
0107-binary-tree-level-order-traversal-ii
0112-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0449-serialize-and-deserialize-bst
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree

Depth-First Search

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0112-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0449-serialize-and-deserialize-bst
0774-maximum-depth-of-n-ary-tree
0775-n-ary-tree-preorder-traversal
0776-n-ary-tree-postorder-traversal

Binary Search Tree

0098-validate-binary-search-tree
0449-serialize-and-deserialize-bst
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree

Sliding Window

0643-maximum-average-subarray-i

Design

0449-serialize-and-deserialize-bst

Linked List

0143-reorder-list
2216-delete-the-middle-node-of-a-linked-list

Database

1827-invalid-tweets
1908-recyclable-and-low-fat-products