leetcode

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

LeetCode Topics

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0141-linked-list-cycle
0268-missing-number
0380-insert-delete-getrandom-o1
0395-longest-substring-with-at-least-k-repeating-characters
0438-find-all-anagrams-in-a-string
0740-delete-and-earn
0768-partition-labels
0816-design-hashset
0926-find-and-replace-pattern
1218-lowest-common-ancestor-of-deepest-leaves
1227-number-of-equivalent-domino-pairs
1460-number-of-substrings-containing-all-three-characters
1500-count-largest-group
1510-find-lucky-integer-in-an-array
1813-maximum-erasure-value
1995-finding-pairs-with-a-certain-sum
2220-find-all-possible-recipes-from-given-supplies
2308-divide-array-into-equal-pairs
2833-count-zero-request-servers
2856-count-complete-subarrays-in-an-array
2888-minimum-index-of-a-valid-split
3225-length-of-longest-subarray-with-at-most-k-frequency
3388-right-triangles
3445-lexicographically-minimum-string-after-removing-stars
3621-minimum-operations-to-make-array-values-equal-to-k
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3753-maximum-difference-between-even-and-odd-frequency-i
3788-maximum-unique-subarray-sum-after-deletion
3934-coupon-code-validator

String

0003-longest-substring-without-repeating-characters
0038-count-and-say
0395-longest-substring-with-at-least-k-repeating-characters
0438-find-all-anagrams-in-a-string
0768-partition-labels
0926-find-and-replace-pattern
1058-lexicographically-smallest-equivalent-string
1250-longest-common-subsequence
1302-delete-characters-to-make-fancy-string
1350-remove-sub-folders-from-the-filesystem
1460-number-of-substrings-containing-all-three-characters
2220-find-all-possible-recipes-from-given-supplies
2260-divide-a-string-into-groups-of-size-k
3243-count-the-number-of-powerful-integers
3396-valid-word
3445-lexicographically-minimum-string-after-removing-stars
3617-find-the-original-typed-string-i
3753-maximum-difference-between-even-and-odd-frequency-i
3931-process-string-with-special-operations-i
3934-coupon-code-validator

Sliding Window

0003-longest-substring-without-repeating-characters
0395-longest-substring-with-at-least-k-repeating-characters
0438-find-all-anagrams-in-a-string
1460-number-of-substrings-containing-all-three-characters
1813-maximum-erasure-value
2394-count-subarrays-with-score-less-than-k
2478-longest-nice-subarray
2833-count-zero-request-servers
2856-count-complete-subarrays-in-an-array
3213-count-subarrays-where-max-element-appears-at-least-k-times
3225-length-of-longest-subarray-with-at-most-k-frequency
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3743-reschedule-meetings-for-maximum-free-time-i

Array

0001-two-sum
0015-3sum
0031-next-permutation
0045-jump-game-ii
0053-maximum-subarray
0075-sort-colors
0118-pascals-triangle
0119-pascals-triangle-ii
0121-best-time-to-buy-and-sell-stock
0152-maximum-product-subarray
0198-house-robber
0238-product-of-array-except-self
0268-missing-number
0289-game-of-life
0300-longest-increasing-subsequence
0303-range-sum-query-immutable
0368-largest-divisible-subset
0380-insert-delete-getrandom-o1
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0735-asteroid-collision
0740-delete-and-earn
0816-design-hashset
0853-most-profit-assigning-work
0926-find-and-replace-pattern
0948-sort-an-array
0983-validate-stack-sequences
1049-minimum-domino-rotations-for-equal-row
1227-number-of-equivalent-domino-pairs
1335-maximum-candies-allocated-to-k-children
1350-remove-sub-folders-from-the-filesystem
1457-minimum-difficulty-of-a-job-schedule
1478-maximum-number-of-events-that-can-be-attended
1510-find-lucky-integer-in-an-array
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1656-count-good-triplets
1813-maximum-erasure-value
1993-sum-of-all-subset-xor-totals
1995-finding-pairs-with-a-certain-sum
2048-build-array-from-permutation
2144-maximum-difference-between-increasing-elements
2160-minimum-operations-to-make-a-uni-value-grid
2220-find-all-possible-recipes-from-given-supplies
2262-solving-questions-with-brainpower
2277-count-equal-and-divisible-pairs-in-an-array
2308-divide-array-into-equal-pairs
2316-count-hills-and-valleys-in-an-array
2320-find-all-k-distant-indices-in-an-array
2394-count-subarrays-with-score-less-than-k
2478-longest-nice-subarray
2497-maximum-matching-of-players-with-trainers
2553-total-cost-to-hire-k-workers
2588-maximum-number-of-points-from-grid-queries
2614-maximum-count-of-positive-integer-and-negative-integer
2665-minimum-time-to-repair-cars
2681-put-marbles-in-bags
2690-house-robber-iv
2699-count-the-number-of-fair-pairs
2833-count-zero-request-servers
2856-count-complete-subarrays-in-an-array
2888-minimum-index-of-a-valid-split
3001-apply-operations-to-maximize-score
3152-maximum-value-of-an-ordered-triplet-ii
3154-maximum-value-of-an-ordered-triplet-i
3213-count-subarrays-where-max-element-appears-at-least-k-times
3225-length-of-longest-subarray-with-at-most-k-frequency
3348-minimum-cost-walk-in-weighted-graph
3388-right-triangles
3430-count-days-without-meetings
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3490-find-the-maximum-length-of-valid-subsequence-i
3621-minimum-operations-to-make-array-values-equal-to-k
3643-zero-array-transformation-ii
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3657-check-if-grid-can-be-cut-into-sections
3738-make-array-non-decreasing
3743-reschedule-meetings-for-maximum-free-time-i
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3788-maximum-unique-subarray-sum-after-deletion
3790-fruits-into-baskets-ii
3934-coupon-code-validator

Binary Search

0268-missing-number
0300-longest-increasing-subsequence
0853-most-profit-assigning-work
1335-maximum-candies-allocated-to-k-children
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2394-count-subarrays-with-score-less-than-k
2614-maximum-count-of-positive-integer-and-negative-integer
2665-minimum-time-to-repair-cars
2690-house-robber-iv
2699-count-the-number-of-fair-pairs
3643-zero-array-transformation-ii
3790-fruits-into-baskets-ii

Counting

1227-number-of-equivalent-domino-pairs
1510-find-lucky-integer-in-an-array
1708-design-parking-system
2308-divide-array-into-equal-pairs
2614-maximum-count-of-positive-integer-and-negative-integer
3388-right-triangles
3753-maximum-difference-between-even-and-odd-frequency-i

Two Pointers

0015-3sum
0031-next-permutation
0075-sort-colors
0141-linked-list-cycle
0768-partition-labels
0853-most-profit-assigning-work
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2320-find-all-k-distant-indices-in-an-array
2497-maximum-matching-of-players-with-trainers
2553-total-cost-to-hire-k-workers
2588-maximum-number-of-points-from-grid-queries
2699-count-the-number-of-fair-pairs

Prefix Sum

0238-product-of-array-except-self
0303-range-sum-query-immutable
2394-count-subarrays-with-score-less-than-k
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3643-zero-array-transformation-ii

Bit Manipulation

0191-number-of-1-bits
0268-missing-number
0338-counting-bits
0371-sum-of-two-integers
1993-sum-of-all-subset-xor-totals
2308-divide-array-into-equal-pairs
2478-longest-nice-subarray
3348-minimum-cost-walk-in-weighted-graph
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3600-find-the-k-th-character-in-string-game-i

Heap (Priority Queue)

0948-sort-an-array
1478-maximum-number-of-events-that-can-be-attended
2553-total-cost-to-hire-k-workers
2588-maximum-number-of-points-from-grid-queries
2681-put-marbles-in-bags
3445-lexicographically-minimum-string-after-removing-stars

Simulation

0289-game-of-life
0735-asteroid-collision
0983-validate-stack-sequences
1708-design-parking-system
2048-build-array-from-permutation
2260-divide-a-string-into-groups-of-size-k
2553-total-cost-to-hire-k-workers
3600-find-the-k-th-character-in-string-game-i
3790-fruits-into-baskets-ii
3931-process-string-with-special-operations-i

Queue

3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Union Find

1058-lexicographically-smallest-equivalent-string
2588-maximum-number-of-points-from-grid-queries
2793-count-the-number-of-complete-components
3348-minimum-cost-walk-in-weighted-graph

Graph

2090-number-of-ways-to-arrive-at-destination
2220-find-all-possible-recipes-from-given-supplies
2793-count-the-number-of-complete-components
3348-minimum-cost-walk-in-weighted-graph

Topological Sort

2090-number-of-ways-to-arrive-at-destination
2220-find-all-possible-recipes-from-given-supplies

Depth-First Search

1218-lowest-common-ancestor-of-deepest-leaves
1350-remove-sub-folders-from-the-filesystem
2793-count-the-number-of-complete-components

Breadth-First Search

0998-check-completeness-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
2588-maximum-number-of-points-from-grid-queries
2793-count-the-number-of-complete-components

Sorting

0015-3sum
0075-sort-colors
0268-missing-number
0368-largest-divisible-subset
0435-non-overlapping-intervals
0853-most-profit-assigning-work
0948-sort-an-array
1478-maximum-number-of-events-that-can-be-attended
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2160-minimum-operations-to-make-a-uni-value-grid
2497-maximum-matching-of-players-with-trainers
2588-maximum-number-of-points-from-grid-queries
2681-put-marbles-in-bags
2699-count-the-number-of-fair-pairs
2833-count-zero-request-servers
2888-minimum-index-of-a-valid-split
3001-apply-operations-to-maximize-score
3430-count-days-without-meetings
3657-check-if-grid-can-be-cut-into-sections
3934-coupon-code-validator

Dynamic Programming

0045-jump-game-ii
0053-maximum-subarray
0118-pascals-triangle
0119-pascals-triangle-ii
0121-best-time-to-buy-and-sell-stock
0152-maximum-product-subarray
0198-house-robber
0300-longest-increasing-subsequence
0338-counting-bits
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0740-delete-and-earn
1250-longest-common-subsequence
1457-minimum-difficulty-of-a-job-schedule
2090-number-of-ways-to-arrive-at-destination
2262-solving-questions-with-brainpower
3243-count-the-number-of-powerful-integers
3490-find-the-maximum-length-of-valid-subsequence-i

Shortest Path

2090-number-of-ways-to-arrive-at-destination

Math

0268-missing-number
0368-largest-divisible-subset
0371-sum-of-two-integers
0380-insert-delete-getrandom-o1
1411-convert-binary-number-in-a-linked-list-to-integer
1500-count-largest-group
1993-sum-of-all-subset-xor-totals
2160-minimum-operations-to-make-a-uni-value-grid
2704-maximum-difference-by-remapping-a-digit
2998-count-symmetric-integers
3001-apply-operations-to-maximize-score
3172-divisible-and-non-divisible-sums-difference
3201-distribute-candies-among-children-ii
3243-count-the-number-of-powerful-integers
3388-right-triangles
3600-find-the-k-th-character-in-string-game-i
3817-maximum-containers-on-a-ship

Matrix

0289-game-of-life
2160-minimum-operations-to-make-a-uni-value-grid
2588-maximum-number-of-points-from-grid-queries

Greedy

0045-jump-game-ii
0435-non-overlapping-intervals
0768-partition-labels
0853-most-profit-assigning-work
1049-minimum-domino-rotations-for-equal-row
1478-maximum-number-of-events-that-can-be-attended
2497-maximum-matching-of-players-with-trainers
2681-put-marbles-in-bags
2704-maximum-difference-by-remapping-a-digit
3001-apply-operations-to-maximize-score
3445-lexicographically-minimum-string-after-removing-stars
3738-make-array-non-decreasing
3743-reschedule-meetings-for-maximum-free-time-i
3788-maximum-unique-subarray-sum-after-deletion

Stack

0735-asteroid-collision
0983-validate-stack-sequences
3001-apply-operations-to-maximize-score
3445-lexicographically-minimum-string-after-removing-stars
3738-make-array-non-decreasing

Monotonic Stack

3001-apply-operations-to-maximize-score
3738-make-array-non-decreasing

Number Theory

3001-apply-operations-to-maximize-score

Linked List

0021-merge-two-sorted-lists
0141-linked-list-cycle
0206-reverse-linked-list
0816-design-hashset
1411-convert-binary-number-in-a-linked-list-to-integer

Database

0177-nth-highest-salary
0196-delete-duplicate-emails
1509-replace-employee-id-with-the-unique-identifier
1664-find-users-with-valid-e-mails
1827-invalid-tweets
1908-recyclable-and-low-fat-products

Divide and Conquer

0053-maximum-subarray
0191-number-of-1-bits
0395-longest-substring-with-at-least-k-repeating-characters
0948-sort-an-array

Tree

0998-check-completeness-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves

Binary Tree

0998-check-completeness-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves

Backtracking

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

Combinatorics

1993-sum-of-all-subset-xor-totals
3201-distribute-candies-among-children-ii
3388-right-triangles

Enumeration

1656-count-good-triplets
1993-sum-of-all-subset-xor-totals
2998-count-symmetric-integers
3201-distribute-candies-among-children-ii

Design

0303-range-sum-query-immutable
0380-insert-delete-getrandom-o1
0816-design-hashset
1708-design-parking-system
1995-finding-pairs-with-a-certain-sum

Hash Function

0816-design-hashset

Merge Sort

0948-sort-an-array

Bucket Sort

0948-sort-an-array

Radix Sort

0948-sort-an-array

Counting Sort

0948-sort-an-array

Recursion

0021-merge-two-sorted-lists
0206-reverse-linked-list
3600-find-the-k-th-character-in-string-game-i

Randomized

0380-insert-delete-getrandom-o1

Trie

1350-remove-sub-folders-from-the-filesystem

Segment Tree

3790-fruits-into-baskets-ii

Ordered Set

3790-fruits-into-baskets-ii