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

LeetCode Topics

Array

0036-valid-sudoku
0041-first-missing-positive
0054-spiral-matrix
0078-subsets
0079-word-search
0108-convert-sorted-array-to-binary-search-tree
0137-single-number-ii
0150-evaluate-reverse-polish-notation
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0169-majority-element
0198-house-robber
0209-minimum-size-subarray-sum
0215-kth-largest-element-in-an-array
0229-majority-element-ii
0287-find-the-duplicate-number
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0414-third-maximum-number
0496-next-greater-element-i
0518-coin-change-ii
0605-can-place-flowers
0645-set-mismatch
0682-baseball-game
0695-max-area-of-island
0739-daily-temperatures
0822-unique-morse-code-words
0841-shortest-distance-to-a-character
0861-flipping-an-image
0940-fruit-into-baskets
0941-sort-array-by-parity
0966-binary-subarrays-with-sum
0978-valid-mountain-array
1001-n-repeated-element-in-size-2n-array
1019-squares-of-a-sorted-array
1137-height-checker
1231-replace-elements-with-greatest-element-on-right-side
1256-rank-transform-of-an-array
1319-unique-number-of-occurrences
1354-find-players-with-zero-or-one-losses
1482-how-many-numbers-are-smaller-than-the-current-number
1510-find-lucky-integer-in-an-array
1528-kids-with-the-greatest-number-of-candies
1582-design-browser-history
1615-range-sum-of-sorted-subarray-sums
1741-sort-array-by-increasing-frequency
1993-sum-of-all-subset-xor-totals
1995-finding-pairs-with-a-certain-sum
2159-two-out-of-three
2190-count-common-words-with-one-occurrence
2271-rearrange-array-elements-by-sign
2274-keep-multiplying-found-values-by-two
2324-find-triangular-sum-of-an-array
2362-minimum-rounds-to-complete-all-tasks
2442-number-of-arithmetic-triplets
2519-find-the-original-array-of-prefix-xor
2524-largest-positive-integer-that-exists-with-its-negative
2707-merge-two-2d-arrays-by-summing-values
2876-number-of-employees-who-met-the-target
3471-minimum-average-of-smallest-and-largest-elements
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3581-the-two-sneaky-numbers-of-digitville
3846-minimum-operations-to-make-array-sum-divisible-by-k
3863-power-grid-maintenance

Hash Table

0012-integer-to-roman
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0030-substring-with-concatenation-of-all-words
0036-valid-sudoku
0041-first-missing-positive
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0169-majority-element
0187-repeated-dna-sequences
0229-majority-element-ii
0290-word-pattern
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0387-first-unique-character-in-a-string
0438-find-all-anagrams-in-a-string
0496-next-greater-element-i
0645-set-mismatch
0822-unique-morse-code-words
0940-fruit-into-baskets
0966-binary-subarrays-with-sum
1001-n-repeated-element-in-size-2n-array
1256-rank-transform-of-an-array
1319-unique-number-of-occurrences
1354-find-players-with-zero-or-one-losses
1460-number-of-substrings-containing-all-three-characters
1469-minimum-number-of-steps-to-make-two-strings-anagram
1482-how-many-numbers-are-smaller-than-the-current-number
1510-find-lucky-integer-in-an-array
1741-sort-array-by-increasing-frequency
1995-finding-pairs-with-a-certain-sum
2159-two-out-of-three
2190-count-common-words-with-one-occurrence
2274-keep-multiplying-found-values-by-two
2362-minimum-rounds-to-complete-all-tasks
2442-number-of-arithmetic-triplets
2524-largest-positive-integer-that-exists-with-its-negative
2707-merge-two-2d-arrays-by-summing-values
3581-the-two-sneaky-numbers-of-digitville
3863-power-grid-maintenance

Bit Manipulation

0078-subsets
0137-single-number-ii
0187-repeated-dna-sequences
0231-power-of-two
0287-find-the-duplicate-number
0461-hamming-distance
0645-set-mismatch
0861-flipping-an-image
1444-number-of-steps-to-reduce-a-number-to-zero
1993-sum-of-all-subset-xor-totals
2159-two-out-of-three
2323-minimum-bit-flips-to-convert-number
2519-find-the-original-array-of-prefix-xor
3600-find-the-k-th-character-in-string-game-i

String

0008-string-to-integer-atoi
0012-integer-to-roman
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0030-substring-with-concatenation-of-all-words
0071-simplify-path
0079-word-search
0187-repeated-dna-sequences
0290-word-pattern
0345-reverse-vowels-of-a-string
0387-first-unique-character-in-a-string
0438-find-all-anagrams-in-a-string
0680-valid-palindrome-ii
0696-count-binary-substrings
0822-unique-morse-code-words
0841-shortest-distance-to-a-character
0874-backspace-string-compare
0953-reverse-only-letters
1128-remove-all-adjacent-duplicates-in-string
1460-number-of-substrings-containing-all-three-characters
1469-minimum-number-of-steps-to-make-two-strings-anagram
1537-maximum-score-after-splitting-a-string
1666-make-the-string-great
1910-check-if-binary-string-has-at-most-one-segment-of-ones
1970-sorting-the-sentence
2190-count-common-words-with-one-occurrence
2304-cells-in-a-range-on-an-excel-sheet
2391-strong-password-checker-ii
3447-clear-digits
3540-hash-divided-string

Counting

0169-majority-element
0229-majority-element-ii
0347-top-k-frequent-elements
0387-first-unique-character-in-a-string
1354-find-players-with-zero-or-one-losses
1469-minimum-number-of-steps-to-make-two-strings-anagram
1510-find-lucky-integer-in-an-array
2190-count-common-words-with-one-occurrence
2362-minimum-rounds-to-complete-all-tasks

Sorting

0169-majority-element
0215-kth-largest-element-in-an-array
0229-majority-element-ii
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0414-third-maximum-number
0645-set-mismatch
0941-sort-array-by-parity
1019-squares-of-a-sorted-array
1137-height-checker
1256-rank-transform-of-an-array
1354-find-players-with-zero-or-one-losses
1482-how-many-numbers-are-smaller-than-the-current-number
1615-range-sum-of-sorted-subarray-sums
1741-sort-array-by-increasing-frequency
1970-sorting-the-sentence
2274-keep-multiplying-found-values-by-two
2524-largest-positive-integer-that-exists-with-its-negative
3471-minimum-average-of-smallest-and-largest-elements

Simulation

0054-spiral-matrix
0682-baseball-game
0861-flipping-an-image
0874-backspace-string-compare
2271-rearrange-array-elements-by-sign
2274-keep-multiplying-found-values-by-two
2299-merge-nodes-in-between-zeros
2324-find-triangular-sum-of-an-array
3447-clear-digits
3540-hash-divided-string
3600-find-the-k-th-character-in-string-game-i

Two Pointers

0019-remove-nth-node-from-end-of-list
0061-rotate-list
0082-remove-duplicates-from-sorted-list-ii
0142-linked-list-cycle-ii
0143-reorder-list
0160-intersection-of-two-linked-lists
0234-palindrome-linked-list
0287-find-the-duplicate-number
0345-reverse-vowels-of-a-string
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0633-sum-of-square-numbers
0680-valid-palindrome-ii
0696-count-binary-substrings
0841-shortest-distance-to-a-character
0861-flipping-an-image
0874-backspace-string-compare
0908-middle-of-the-linked-list
0941-sort-array-by-parity
0953-reverse-only-letters
1019-squares-of-a-sorted-array
1615-range-sum-of-sorted-subarray-sums
2216-delete-the-middle-node-of-a-linked-list
2271-rearrange-array-elements-by-sign
2442-number-of-arithmetic-triplets
2524-largest-positive-integer-that-exists-with-its-negative
2707-merge-two-2d-arrays-by-summing-values
3471-minimum-average-of-smallest-and-largest-elements

Enumeration

1993-sum-of-all-subset-xor-totals
2442-number-of-arithmetic-triplets

Math

0002-add-two-numbers
0012-integer-to-roman
0013-roman-to-integer
0150-evaluate-reverse-polish-notation
0231-power-of-two
0326-power-of-three
0445-add-two-numbers-ii
0633-sum-of-square-numbers
1411-convert-binary-number-in-a-linked-list-to-integer
1444-number-of-steps-to-reduce-a-number-to-zero
1993-sum-of-all-subset-xor-totals
2238-a-number-after-a-double-reversal
2324-find-triangular-sum-of-an-array
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3581-the-two-sneaky-numbers-of-digitville
3600-find-the-k-th-character-in-string-game-i
3846-minimum-operations-to-make-array-sum-divisible-by-k

Combinatorics

1993-sum-of-all-subset-xor-totals
2324-find-triangular-sum-of-an-array

Greedy

0605-can-place-flowers
0680-valid-palindrome-ii
2362-minimum-rounds-to-complete-all-tasks

Binary Search

0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0209-minimum-size-subarray-sum
0287-find-the-duplicate-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0633-sum-of-square-numbers
1615-range-sum-of-sorted-subarray-sums

Divide and Conquer

0108-convert-sorted-array-to-binary-search-tree
0109-convert-sorted-list-to-binary-search-tree
0169-majority-element
0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements

Queue

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

Counting Sort

1137-height-checker
1482-how-many-numbers-are-smaller-than-the-current-number

Sliding Window

0030-substring-with-concatenation-of-all-words
0187-repeated-dna-sequences
0209-minimum-size-subarray-sum
0438-find-all-anagrams-in-a-string
0940-fruit-into-baskets
0966-binary-subarrays-with-sum
1460-number-of-substrings-containing-all-three-characters

Prefix Sum

0209-minimum-size-subarray-sum
0966-binary-subarrays-with-sum
1537-maximum-score-after-splitting-a-string
1615-range-sum-of-sorted-subarray-sums

Matrix

0036-valid-sudoku
0054-spiral-matrix
0079-word-search
0695-max-area-of-island
0861-flipping-an-image

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
3863-power-grid-maintenance

Bucket Sort

0347-top-k-frequent-elements

Quickselect

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0024-swap-nodes-in-pairs
0061-rotate-list
0082-remove-duplicates-from-sorted-list-ii
0109-convert-sorted-list-to-binary-search-tree
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0142-linked-list-cycle-ii
0143-reorder-list
0160-intersection-of-two-linked-lists
0203-remove-linked-list-elements
0206-reverse-linked-list
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0445-add-two-numbers-ii
0838-design-linked-list
0908-middle-of-the-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer
1582-design-browser-history
2216-delete-the-middle-node-of-a-linked-list
2299-merge-nodes-in-between-zeros
2573-remove-nodes-from-linked-list

Recursion

0002-add-two-numbers
0024-swap-nodes-in-pairs
0143-reorder-list
0203-remove-linked-list-elements
0206-reverse-linked-list
0231-power-of-two
0234-palindrome-linked-list
0326-power-of-three
2573-remove-nodes-from-linked-list
3600-find-the-k-th-character-in-string-game-i

Stack

0071-simplify-path
0094-binary-tree-inorder-traversal
0114-flatten-binary-tree-to-linked-list
0143-reorder-list
0150-evaluate-reverse-polish-notation
0234-palindrome-linked-list
0445-add-two-numbers-ii
0496-next-greater-element-i
0682-baseball-game
0739-daily-temperatures
0874-backspace-string-compare
1128-remove-all-adjacent-duplicates-in-string
1582-design-browser-history
1666-make-the-string-great
2573-remove-nodes-from-linked-list
3447-clear-digits

Monotonic Stack

0496-next-greater-element-i
0739-daily-temperatures
2573-remove-nodes-from-linked-list

Rolling Hash

0187-repeated-dna-sequences

Hash Function

0187-repeated-dna-sequences

Backtracking

0017-letter-combinations-of-a-phone-number
0078-subsets
0079-word-search
0813-all-paths-from-source-to-target
1993-sum-of-all-subset-xor-totals

Database

0175-combine-two-tables
0197-rising-temperature
0577-employee-bonus
0584-find-customer-referee
0595-big-countries
0620-not-boring-movies
1153-product-sales-analysis-i
1161-project-employees-i
1258-article-views-i
1390-average-selling-price
1509-replace-employee-id-with-the-unique-identifier
1724-customer-who-visited-but-did-not-make-any-transactions
1801-average-time-of-process-per-machine
1827-invalid-tweets
1908-recyclable-and-low-fat-products

Depth-First Search

0079-word-search
0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0207-course-schedule
0210-course-schedule-ii
0547-number-of-provinces
0695-max-area-of-island
0813-all-paths-from-source-to-target
0975-range-sum-of-bst
1114-binary-search-tree-to-greater-sum-tree
2121-find-if-path-exists-in-graph
2793-count-the-number-of-complete-components
3863-power-grid-maintenance

Design

0838-design-linked-list
1582-design-browser-history
1995-finding-pairs-with-a-certain-sum

Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0108-convert-sorted-array-to-binary-search-tree
0109-convert-sorted-list-to-binary-search-tree
0110-balanced-binary-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0975-range-sum-of-bst
1114-binary-search-tree-to-greater-sum-tree

Binary Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0108-convert-sorted-array-to-binary-search-tree
0109-convert-sorted-list-to-binary-search-tree
0110-balanced-binary-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0975-range-sum-of-bst
1114-binary-search-tree-to-greater-sum-tree

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0112-path-sum
0116-populating-next-right-pointers-in-each-node
0207-course-schedule
0210-course-schedule-ii
0547-number-of-provinces
0695-max-area-of-island
0813-all-paths-from-source-to-target
2121-find-if-path-exists-in-graph
2793-count-the-number-of-complete-components
3863-power-grid-maintenance

Binary Search Tree

0108-convert-sorted-array-to-binary-search-tree
0109-convert-sorted-list-to-binary-search-tree
0975-range-sum-of-bst
1114-binary-search-tree-to-greater-sum-tree

Graph

0207-course-schedule
0210-course-schedule-ii
0547-number-of-provinces
0813-all-paths-from-source-to-target
1916-find-center-of-star-graph
2121-find-if-path-exists-in-graph
2793-count-the-number-of-complete-components
3863-power-grid-maintenance

Union Find

0547-number-of-provinces
0695-max-area-of-island
2121-find-if-path-exists-in-graph
2793-count-the-number-of-complete-components
3863-power-grid-maintenance

Dynamic Programming

0198-house-robber
0518-coin-change-ii

Topological Sort

0207-course-schedule
0210-course-schedule-ii

Ordered Set

3863-power-grid-maintenance

Doubly-Linked List

1582-design-browser-history

Data Stream

1582-design-browser-history