alg-leet-code

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

LeetCode Topics

Array

0001-two-sum
0011-container-with-most-water
0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
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
0121-best-time-to-buy-and-sell-stock
0136-single-number
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0198-house-robber
0209-minimum-size-subarray-sum
0215-kth-largest-element-in-an-array
0219-contains-duplicate-ii
0238-product-of-array-except-self
0275-h-index-ii
0283-move-zeroes
0303-range-sum-query-immutable
0334-increasing-triplet-subsequence
0350-intersection-of-two-arrays-ii
0435-non-overlapping-intervals
0436-find-right-interval
0452-minimum-number-of-arrows-to-burst-balloons
0455-assign-cookies
0525-contiguous-array
0540-single-element-in-a-sorted-array
0561-array-partition
0605-can-place-flowers
0611-valid-triangle-number
0643-maximum-average-subarray-i
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0724-find-pivot-index
0735-asteroid-collision
0739-daily-temperatures
0745-find-smallest-letter-greater-than-target
0747-min-cost-climbing-stairs
0797-rabbits-in-forest
0882-peak-index-in-a-mountain-array
0890-lemonade-change
0907-koko-eating-bananas
1019-squares-of-a-sorted-array
1046-max-consecutive-ones-iii
1095-two-city-scheduling
1249-snapshot-array
1319-unique-number-of-occurrences
1392-find-the-difference-of-two-arrays
1397-search-suggestions-system
1476-count-negative-numbers-in-a-sorted-matrix
1528-kids-with-the-greatest-number-of-candies
1586-longest-subarray-of-1s-after-deleting-one-element
1603-running-sum-of-1d-array
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1646-kth-missing-positive-number
1791-richest-customer-wealth
1798-max-number-of-k-sum-pairs
1833-find-the-highest-altitude
2219-maximum-number-of-words-found-in-sentences
2231-find-first-palindromic-string-in-the-array
2392-successful-pairs-of-spells-and-potions
2428-equal-row-and-column-pairs
2553-total-cost-to-hire-k-workers
2624-difference-between-element-sum-and-digit-sum-of-an-array
2636-maximum-subsequence-score
2714-left-and-right-sum-differences
2876-number-of-employees-who-met-the-target
3194-find-words-containing-character
3206-find-common-elements-between-two-arrays
3221-find-the-peaks
3226-minimum-number-game
3227-find-missing-and-repeated-values
3321-type-of-triangle

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0303-range-sum-query-immutable
0525-contiguous-array
0724-find-pivot-index
1046-max-consecutive-ones-iii
1603-running-sum-of-1d-array
1833-find-the-highest-altitude
2714-left-and-right-sum-differences

Matrix

0074-search-a-2d-matrix
1476-count-negative-numbers-in-a-sorted-matrix
1791-richest-customer-wealth
2428-equal-row-and-column-pairs
3227-find-missing-and-repeated-values

Math

0062-unique-paths
0069-sqrtx
0070-climbing-stairs
0258-add-digits
0367-valid-perfect-square
0412-fizz-buzz
0441-arranging-coins
0797-rabbits-in-forest
1146-greatest-common-divisor-of-strings
1236-n-th-tribonacci-number
1406-subtract-the-product-and-sum-of-digits-of-an-integer
1444-number-of-steps-to-reduce-a-number-to-zero
1448-maximum-69-number
1610-xor-operation-in-an-array
2608-count-the-digits-that-divide-a-number
2624-difference-between-element-sum-and-digit-sum-of-an-array
2752-sum-multiples
2812-find-the-maximum-achievable-number
3172-divisible-and-non-divisible-sums-difference
3227-find-missing-and-repeated-values
3275-minimum-number-of-pushes-to-type-word-i
3321-type-of-triangle
3625-stone-removal-game

String

0003-longest-substring-without-repeating-characters
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0028-find-the-index-of-the-first-occurrence-in-a-string
0072-edit-distance
0125-valid-palindrome
0151-reverse-words-in-a-string
0208-implement-trie-prefix-tree
0242-valid-anagram
0344-reverse-string
0345-reverse-vowels-of-a-string
0383-ransom-note
0387-first-unique-character-in-a-string
0392-is-subsequence
0394-decode-string
0409-longest-palindrome
0412-fizz-buzz
0438-find-all-anagrams-in-a-string
0443-string-compression
0583-delete-operation-for-two-strings
0649-dota2-senate
0742-to-lower-case
0778-reorganize-string
1023-time-based-key-value-store
1146-greatest-common-divisor-of-strings
1250-longest-common-subsequence
1397-search-suggestions-system
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1777-determine-if-two-strings-are-close
1894-merge-strings-alternately
1960-check-if-the-sentence-is-pangram
2088-minimum-time-to-type-word-using-special-typewriter
2219-maximum-number-of-words-found-in-sentences
2231-find-first-palindromic-string-in-the-array
2235-capitalize-the-title
2337-remove-digit-from-number-to-maximize-result
2345-minimum-number-of-operations-to-convert-time
3194-find-words-containing-character
3207-make-three-strings-equal
3275-minimum-number-of-pushes-to-type-word-i
3312-number-of-changing-keys

Simulation

0258-add-digits
0412-fizz-buzz
0735-asteroid-collision
2428-equal-row-and-column-pairs
2553-total-cost-to-hire-k-workers
3226-minimum-number-game
3625-stone-removal-game

Bit Manipulation

0136-single-number
0338-counting-bits
1441-minimum-flips-to-make-a-or-b-equal-to-c
1444-number-of-steps-to-reduce-a-number-to-zero
1610-xor-operation-in-an-array

Linked List

0206-reverse-linked-list
0328-odd-even-linked-list
0908-middle-of-the-linked-list
2216-delete-the-middle-node-of-a-linked-list
2236-maximum-twin-sum-of-a-linked-list

Two Pointers

0011-container-with-most-water
0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0125-valid-palindrome
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0283-move-zeroes
0344-reverse-string
0345-reverse-vowels-of-a-string
0350-intersection-of-two-arrays-ii
0392-is-subsequence
0443-string-compression
0455-assign-cookies
0611-valid-triangle-number
0908-middle-of-the-linked-list
1019-squares-of-a-sorted-array
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1798-max-number-of-k-sum-pairs
1894-merge-strings-alternately
2216-delete-the-middle-node-of-a-linked-list
2231-find-first-palindromic-string-in-the-array
2236-maximum-twin-sum-of-a-linked-list
2392-successful-pairs-of-spells-and-potions
2553-total-cost-to-hire-k-workers

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0017-letter-combinations-of-a-phone-number
0208-implement-trie-prefix-tree
0219-contains-duplicate-ii
0242-valid-anagram
0350-intersection-of-two-arrays-ii
0383-ransom-note
0387-first-unique-character-in-a-string
0409-longest-palindrome
0438-find-all-anagrams-in-a-string
0525-contiguous-array
0778-reorganize-string
0797-rabbits-in-forest
1023-time-based-key-value-store
1249-snapshot-array
1319-unique-number-of-occurrences
1392-find-the-difference-of-two-arrays
1777-determine-if-two-strings-are-close
1798-max-number-of-k-sum-pairs
1960-check-if-the-sentence-is-pangram
2413-smallest-number-in-infinite-set
2428-equal-row-and-column-pairs
3206-find-common-elements-between-two-arrays
3227-find-missing-and-repeated-values

Counting

0383-ransom-note
0387-first-unique-character-in-a-string
0778-reorganize-string
1777-determine-if-two-strings-are-close

Binary Search

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
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0275-h-index-ii
0278-first-bad-version
0350-intersection-of-two-arrays-ii
0367-valid-perfect-square
0374-guess-number-higher-or-lower
0436-find-right-interval
0441-arranging-coins
0540-single-element-in-a-sorted-array
0611-valid-triangle-number
0745-find-smallest-letter-greater-than-target
0882-peak-index-in-a-mountain-array
0907-koko-eating-bananas
1023-time-based-key-value-store
1046-max-consecutive-ones-iii
1249-snapshot-array
1397-search-suggestions-system
1476-count-negative-numbers-in-a-sorted-matrix
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1646-kth-missing-positive-number
2392-successful-pairs-of-spells-and-potions

Interactive

0278-first-bad-version
0374-guess-number-higher-or-lower

Sorting

0015-3sum
0215-kth-largest-element-in-an-array
0242-valid-anagram
0350-intersection-of-two-arrays-ii
0435-non-overlapping-intervals
0436-find-right-interval
0452-minimum-number-of-arrows-to-burst-balloons
0455-assign-cookies
0561-array-partition
0611-valid-triangle-number
0778-reorganize-string
1019-squares-of-a-sorted-array
1095-two-city-scheduling
1397-search-suggestions-system
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1777-determine-if-two-strings-are-close
1798-max-number-of-k-sum-pairs
2392-successful-pairs-of-spells-and-potions
2636-maximum-subsequence-score
3226-minimum-number-game
3321-type-of-triangle

Design

0208-implement-trie-prefix-tree
0303-range-sum-query-immutable
0937-online-stock-span
0969-number-of-recent-calls
1023-time-based-key-value-store
1249-snapshot-array
2413-smallest-number-in-infinite-set

Greedy

0011-container-with-most-water
0334-increasing-triplet-subsequence
0409-longest-palindrome
0435-non-overlapping-intervals
0452-minimum-number-of-arrows-to-burst-balloons
0455-assign-cookies
0561-array-partition
0605-can-place-flowers
0611-valid-triangle-number
0649-dota2-senate
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0778-reorganize-string
0797-rabbits-in-forest
0890-lemonade-change
1095-two-city-scheduling
1448-maximum-69-number
2088-minimum-time-to-type-word-using-special-typewriter
2337-remove-digit-from-number-to-maximize-result
2345-minimum-number-of-operations-to-convert-time
2636-maximum-subsequence-score
3275-minimum-number-of-pushes-to-type-word-i

Queue

0387-first-unique-character-in-a-string
0649-dota2-senate
0969-number-of-recent-calls

String Matching

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

Trie

0014-longest-common-prefix
0208-implement-trie-prefix-tree
1397-search-suggestions-system

Dynamic Programming

0062-unique-paths
0070-climbing-stairs
0072-edit-distance
0121-best-time-to-buy-and-sell-stock
0198-house-robber
0338-counting-bits
0392-is-subsequence
0435-non-overlapping-intervals
0583-delete-operation-for-two-strings
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0747-min-cost-climbing-stairs
0806-domino-and-tromino-tiling
1236-n-th-tribonacci-number
1250-longest-common-subsequence
1586-longest-subarray-of-1s-after-deleting-one-element

Memoization

0070-climbing-stairs
1236-n-th-tribonacci-number

Sliding Window

0003-longest-substring-without-repeating-characters
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0438-find-all-anagrams-in-a-string
0643-maximum-average-subarray-i
1046-max-consecutive-ones-iii
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1586-longest-subarray-of-1s-after-deleting-one-element

Data Stream

0937-online-stock-span
0969-number-of-recent-calls

Recursion

0206-reverse-linked-list
0394-decode-string

Stack

0144-binary-tree-preorder-traversal
0394-decode-string
0735-asteroid-collision
0739-daily-temperatures
0937-online-stock-span
2236-maximum-twin-sum-of-a-linked-list

Monotonic Stack

0739-daily-temperatures
0937-online-stock-span

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0778-reorganize-string
1397-search-suggestions-system
2413-smallest-number-in-infinite-set
2553-total-cost-to-hire-k-workers
2636-maximum-subsequence-score
3226-minimum-number-game

Combinatorics

0062-unique-paths

Divide and Conquer

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

Quickselect

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

Ordered Set

2413-smallest-number-in-infinite-set

Tree

0104-maximum-depth-of-binary-tree
0144-binary-tree-preorder-traversal
0450-delete-node-in-a-bst
0783-search-in-a-binary-search-tree
0904-leaf-similar-trees

Depth-First Search

0104-maximum-depth-of-binary-tree
0144-binary-tree-preorder-traversal
0871-keys-and-rooms
0904-leaf-similar-trees

Breadth-First Search

0104-maximum-depth-of-binary-tree
0871-keys-and-rooms

Binary Tree

0104-maximum-depth-of-binary-tree
0144-binary-tree-preorder-traversal
0450-delete-node-in-a-bst
0783-search-in-a-binary-search-tree
0904-leaf-similar-trees

Binary Search Tree

0450-delete-node-in-a-bst
0783-search-in-a-binary-search-tree

Backtracking

0017-letter-combinations-of-a-phone-number

Enumeration

2337-remove-digit-from-number-to-maximize-result
3221-find-the-peaks

Graph

0871-keys-and-rooms

Database

1908-recyclable-and-low-fat-products

Counting Sort

0561-array-partition

Number Theory

0258-add-digits