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
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0049-group-anagrams
0053-maximum-subarray
0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0136-single-number
0152-maximum-product-subarray
0169-majority-element
0189-rotate-array
0198-house-robber
0200-number-of-islands
0209-minimum-size-subarray-sum
0215-kth-largest-element-in-an-array
0268-missing-number
0283-move-zeroes
0287-find-the-duplicate-number
0485-max-consecutive-ones
0560-subarray-sum-equals-k
0898-transpose-matrix
0952-word-subsets
0954-maximum-sum-circular-subarray
0994-rotting-oranges
1010-pairs-of-songs-with-total-durations-divisible-by-60
1094-car-pooling
1112-find-words-that-can-be-formed-by-characters
1352-product-of-the-last-k-numbers
1353-maximum-number-of-events-that-can-be-attended
1360-maximum-length-of-a-concatenated-string-with-unique-characters
1470-shuffle-the-array
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1570-final-prices-with-a-special-discount-in-a-shop
1878-check-if-array-is-sorted-and-rotated
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1917-maximum-average-pass-ratio
2271-rearrange-array-elements-by-sign
2292-counting-words-with-a-given-prefix
2465-shifting-letters-ii
2533-bitwise-xor-of-all-pairings
2685-first-completely-painted-row-or-column
2691-count-vowel-strings-in-ranges
2695-find-score-of-an-array-after-marking-all-elements
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
3309-count-prefix-and-suffix-pairs-i
3355-zero-array-transformation-i
3555-final-array-state-after-k-multiplication-operations-i

Hash Table

0001-two-sum
0049-group-anagrams
0141-linked-list-cycle
0160-intersection-of-two-linked-lists
0166-fraction-to-recurring-decimal
0169-majority-element
0268-missing-number
0389-find-the-difference
0560-subarray-sum-equals-k
0952-word-subsets
1010-pairs-of-songs-with-total-durations-divisible-by-60
1112-find-words-that-can-be-formed-by-characters
1502-construct-k-palindrome-strings
2059-unique-length-3-palindromic-subsequences
2300-construct-string-with-repeat-limit
2685-first-completely-painted-row-or-column
2695-find-score-of-an-array-after-marking-all-elements
2766-find-the-prefix-common-array-of-two-arrays
3455-minimum-length-of-string-after-operations

Sorting

0049-group-anagrams
0169-majority-element
0215-kth-largest-element-in-an-array
0268-missing-number
0389-find-the-difference
1094-car-pooling
1353-maximum-number-of-events-that-can-be-attended
2695-find-score-of-an-array-after-marking-all-elements

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
1094-car-pooling
1353-maximum-number-of-events-that-can-be-attended
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1917-maximum-average-pass-ratio
2300-construct-string-with-repeat-limit
2695-find-score-of-an-array-after-marking-all-elements
3555-final-array-state-after-k-multiplication-operations-i

Simulation

0898-transpose-matrix
1094-car-pooling
1806-count-of-matches-in-tournament
2271-rearrange-array-elements-by-sign
2695-find-score-of-an-array-after-marking-all-elements
3555-final-array-state-after-k-multiplication-operations-i

Greedy

0011-container-with-most-water
0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0680-valid-palindrome-ii
0957-minimum-add-to-make-parentheses-valid
1353-maximum-number-of-events-that-can-be-attended
1502-construct-k-palindrome-strings
1917-maximum-average-pass-ratio
2032-largest-odd-number-in-string
2221-check-if-a-parentheses-string-can-be-valid
2300-construct-string-with-repeat-limit
2509-minimize-xor

Math

0050-powx-n
0166-fraction-to-recurring-decimal
0189-rotate-array
0231-power-of-two
0268-missing-number
0273-integer-to-english-words
1352-product-of-the-last-k-numbers
1806-count-of-matches-in-tournament
2032-largest-odd-number-in-string
3555-final-array-state-after-k-multiplication-operations-i

String

0028-find-the-index-of-the-first-occurrence-in-a-string
0038-count-and-say
0049-group-anagrams
0166-fraction-to-recurring-decimal
0273-integer-to-english-words
0389-find-the-difference
0680-valid-palindrome-ii
0952-word-subsets
0957-minimum-add-to-make-parentheses-valid
1112-find-words-that-can-be-formed-by-characters
1360-maximum-length-of-a-concatenated-string-with-unique-characters
1502-construct-k-palindrome-strings
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
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
2300-construct-string-with-repeat-limit
2346-largest-3-same-digit-number-in-string
2465-shifting-letters-ii
2691-count-vowel-strings-in-ranges
3309-count-prefix-and-suffix-pairs-i
3455-minimum-length-of-string-after-operations

Counting

0169-majority-element
1010-pairs-of-songs-with-total-durations-divisible-by-60
1112-find-words-that-can-be-formed-by-characters
1502-construct-k-palindrome-strings
2300-construct-string-with-repeat-limit
3455-minimum-length-of-string-after-operations

Stack

0234-palindrome-linked-list
0957-minimum-add-to-make-parentheses-valid
1570-final-prices-with-a-special-discount-in-a-shop
2221-check-if-a-parentheses-string-can-be-valid

Monotonic Stack

1570-final-prices-with-a-special-discount-in-a-shop

Prefix Sum

0209-minimum-size-subarray-sum
0560-subarray-sum-equals-k
1094-car-pooling
1352-product-of-the-last-k-numbers
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
2059-unique-length-3-palindromic-subsequences
2465-shifting-letters-ii
2691-count-vowel-strings-in-ranges
3355-zero-array-transformation-i

Bit Manipulation

0136-single-number
0231-power-of-two
0268-missing-number
0287-find-the-duplicate-number
0389-find-the-difference
1360-maximum-length-of-a-concatenated-string-with-unique-characters
2059-unique-length-3-palindromic-subsequences
2509-minimize-xor
2533-bitwise-xor-of-all-pairings
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor

Backtracking

1360-maximum-length-of-a-concatenated-string-with-unique-characters

Trie

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

Rolling Hash

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

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i

Hash Function

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

Matrix

0200-number-of-islands
0898-transpose-matrix
0994-rotting-oranges
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2685-first-completely-painted-row-or-column

Brainteaser

2533-bitwise-xor-of-all-pairings

Breadth-First Search

0200-number-of-islands
0994-rotting-oranges
1448-count-good-nodes-in-binary-tree
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

Shortest Path

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

Two Pointers

0011-container-with-most-water
0026-remove-duplicates-from-sorted-array
0028-find-the-index-of-the-first-occurrence-in-a-string
0031-next-permutation
0141-linked-list-cycle
0160-intersection-of-two-linked-lists
0189-rotate-array
0234-palindrome-linked-list
0283-move-zeroes
0287-find-the-duplicate-number
0680-valid-palindrome-ii
2271-rearrange-array-elements-by-sign

Binary Search

0004-median-of-two-sorted-arrays
0209-minimum-size-subarray-sum
0268-missing-number
0287-find-the-duplicate-number

Divide and Conquer

0004-median-of-two-sorted-arrays
0053-maximum-subarray
0169-majority-element
0215-kth-largest-element-in-an-array
0954-maximum-sum-circular-subarray

Dynamic Programming

0053-maximum-subarray
0122-best-time-to-buy-and-sell-stock-ii
0152-maximum-product-subarray
0198-house-robber
0954-maximum-sum-circular-subarray

Quickselect

0215-kth-largest-element-in-an-array

Queue

0954-maximum-sum-circular-subarray

Monotonic Queue

0954-maximum-sum-circular-subarray

Sliding Window

0209-minimum-size-subarray-sum

Linked List

0021-merge-two-sorted-lists
0083-remove-duplicates-from-sorted-list
0141-linked-list-cycle
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0234-palindrome-linked-list

Recursion

0021-merge-two-sorted-lists
0050-powx-n
0206-reverse-linked-list
0231-power-of-two
0234-palindrome-linked-list
0273-integer-to-english-words

Depth-First Search

0200-number-of-islands
0230-kth-smallest-element-in-a-bst
1448-count-good-nodes-in-binary-tree

Union-Find

0200-number-of-islands

Design

1352-product-of-the-last-k-numbers

Data Stream

1352-product-of-the-last-k-numbers

Tree

0230-kth-smallest-element-in-a-bst
1448-count-good-nodes-in-binary-tree

Binary Search Tree

0230-kth-smallest-element-in-a-bst

Binary Tree

0230-kth-smallest-element-in-a-bst
1448-count-good-nodes-in-binary-tree