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
0014-longest-common-prefix
0015-3sum
0018-4sum
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0041-first-missing-positive
0042-trapping-rain-water
0046-permutations
0047-permutations-ii
0051-n-queens
0053-maximum-subarray
0054-spiral-matrix
0066-plus-one
0073-set-matrix-zeroes
0075-sort-colors
0078-subsets
0079-word-search
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0088-merge-sorted-array
0090-subsets-ii
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0153-find-minimum-in-rotated-sorted-array
0169-majority-element
0189-rotate-array
0209-minimum-size-subarray-sum
0215-kth-largest-element-in-an-array
0216-combination-sum-iii
0219-contains-duplicate-ii
0229-majority-element-ii
0238-product-of-array-except-self
0239-sliding-window-maximum
0268-missing-number
0283-move-zeroes
0303-range-sum-query-immutable
0334-increasing-triplet-subsequence
0485-max-consecutive-ones
0494-target-sum
0496-next-greater-element-i
0503-next-greater-element-ii
0560-subarray-sum-equals-k
0628-maximum-product-of-three-numbers
0645-set-mismatch
0704-binary-search
0713-subarray-product-less-than-k
0904-fruit-into-baskets
0912-sort-an-array
0930-binary-subarrays-with-sum
0953-verifying-an-alien-dictionary
0992-subarrays-with-k-different-integers
1004-max-consecutive-ones-iii
1248-count-number-of-nice-subarrays
1260-shift-2d-grid
1295-find-numbers-with-even-number-of-digits
1299-replace-elements-with-greatest-element-on-right-side
1331-rank-transform-of-an-array
1423-maximum-points-you-can-obtain-from-cards
1470-shuffle-the-array
1498-number-of-subsequences-that-satisfy-the-given-sum-condition
1537-get-the-maximum-score
1732-find-the-highest-altitude
1752-check-if-array-is-sorted-and-rotated
1833-maximum-ice-cream-bars
1848-minimum-distance-to-the-target-element
1855-maximum-distance-between-a-pair-of-values
1861-rotating-the-box
1886-determine-whether-matrix-can-be-obtained-by-rotation
1929-concatenation-of-array
1979-find-greatest-common-divisor-of-array
1980-find-unique-binary-string
2006-count-number-of-pairs-with-absolute-difference-k
2078-two-furthest-houses-with-different-colors
2114-maximum-number-of-words-found-in-sentences
2302-count-subarrays-with-score-less-than-k
2515-shortest-distance-to-target-string-in-a-circular-array
2553-separate-the-digits-in-an-array
2574-left-and-right-sum-differences
2656-maximum-sum-with-exactly-k-elements
2784-check-if-array-is-good
2906-construct-product-matrix
2946-matrix-similarity-after-cyclic-shifts
3300-minimum-element-after-replacement-with-digit-sum
3477-fruits-into-baskets-ii
3548-equal-sum-grid-partition-ii
3567-minimum-absolute-difference-in-sliding-submatrix
3643-flip-square-submatrix-vertically
3689-maximum-total-subarray-value-i
3708-longest-fibonacci-subarray
3818-minimum-prefix-removal-to-make-array-strictly-increasing
3838-weighted-word-mapping
3854-minimum-operations-to-make-array-parity-alternating
3867-sum-of-gcd-of-formed-pairs

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0037-sudoku-solver
0041-first-missing-positive
0073-set-matrix-zeroes
0076-minimum-window-substring
0128-longest-consecutive-sequence
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0160-intersection-of-two-linked-lists
0169-majority-element
0202-happy-number
0205-isomorphic-strings
0219-contains-duplicate-ii
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0395-longest-substring-with-at-least-k-repeating-characters
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0451-sort-characters-by-frequency
0460-lfu-cache
0496-next-greater-element-i
0560-subarray-sum-equals-k
0645-set-mismatch
0904-fruit-into-baskets
0930-binary-subarrays-with-sum
0953-verifying-an-alien-dictionary
0992-subarrays-with-k-different-integers
1189-maximum-number-of-balloons
1248-count-number-of-nice-subarrays
1331-rank-transform-of-an-array
1358-number-of-substrings-containing-all-three-characters
1781-sum-of-beauty-of-all-substrings
1980-find-unique-binary-string
2006-count-number-of-pairs-with-absolute-difference-k
2784-check-if-array-is-good
3120-count-the-number-of-special-characters-i
3121-count-the-number-of-special-characters-ii
3325-count-substrings-with-k-frequency-characters-i
3548-equal-sum-grid-partition-ii

Math

0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0050-powx-n
0060-permutation-sequence
0066-plus-one
0069-sqrtx
0070-climbing-stairs
0189-rotate-array
0202-happy-number
0258-add-digits
0268-missing-number
0282-expression-add-operators
0326-power-of-three
0367-valid-perfect-square
0628-maximum-product-of-three-numbers
0728-self-dividing-numbers
0779-k-th-symbol-in-grammar
0788-rotated-digits
0899-orderly-queue
1248-count-number-of-nice-subarrays
1295-find-numbers-with-even-number-of-digits
1323-maximum-69-number
1716-calculate-money-in-leetcode-bank
1903-largest-odd-number-in-string
1922-count-good-numbers
1979-find-greatest-common-divisor-of-array
2235-add-two-integers
2946-matrix-similarity-after-cyclic-shifts
3300-minimum-element-after-replacement-with-digit-sum
3536-maximum-product-of-two-digits
3658-gcd-of-odd-and-even-sums
3754-concatenate-non-zero-digits-and-multiply-by-sum-i
3783-mirror-distance-of-an-integer
3867-sum-of-gcd-of-formed-pairs

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0018-4sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0042-trapping-rain-water
0061-rotate-list
0075-sort-colors
0082-remove-duplicates-from-sorted-list-ii
0088-merge-sorted-array
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0189-rotate-array
0202-happy-number
0234-palindrome-linked-list
0283-move-zeroes
0344-reverse-string
0876-middle-of-the-linked-list
1498-number-of-subsequences-that-satisfy-the-given-sum-condition
1537-get-the-maximum-score
1855-maximum-distance-between-a-pair-of-values
1861-rotating-the-box
2095-delete-the-middle-node-of-a-linked-list
3643-flip-square-submatrix-vertically
3867-sum-of-gcd-of-formed-pairs

Divide and Conquer

0004-median-of-two-sorted-arrays
0053-maximum-subarray
0148-sort-list
0169-majority-element
0215-kth-largest-element-in-an-array
0395-longest-substring-with-at-least-k-repeating-characters
0912-sort-an-array

Sorting

0015-3sum
0018-4sum
0047-permutations-ii
0075-sort-colors
0088-merge-sorted-array
0148-sort-list
0169-majority-element
0215-kth-largest-element-in-an-array
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0451-sort-characters-by-frequency
0628-maximum-product-of-three-numbers
0645-set-mismatch
0899-orderly-queue
0912-sort-an-array
1331-rank-transform-of-an-array
1498-number-of-subsequences-that-satisfy-the-given-sum-condition
1833-maximum-ice-cream-bars
2784-check-if-array-is-good
3517-smallest-palindromic-rearrangement-i
3536-maximum-product-of-two-digits
3567-minimum-absolute-difference-in-sliding-submatrix
3867-sum-of-gcd-of-formed-pairs

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0239-sliding-window-maximum
0451-sort-characters-by-frequency
0912-sort-an-array

Quickselect

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

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0006-zigzag-conversion
0008-string-to-integer-atoi
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0020-valid-parentheses
0022-generate-parentheses
0038-count-and-say
0076-minimum-window-substring
0079-word-search
0131-palindrome-partitioning
0151-reverse-words-in-a-string
0205-isomorphic-strings
0242-valid-anagram
0282-expression-add-operators
0316-remove-duplicate-letters
0344-reverse-string
0395-longest-substring-with-at-least-k-repeating-characters
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0451-sort-characters-by-frequency
0796-rotate-string
0899-orderly-queue
0921-minimum-add-to-make-parentheses-valid
0953-verifying-an-alien-dictionary
1021-remove-outermost-parentheses
1047-remove-all-adjacent-duplicates-in-string
1081-smallest-subsequence-of-distinct-characters
1189-maximum-number-of-balloons
1209-remove-all-adjacent-duplicates-in-string-ii
1358-number-of-substrings-containing-all-three-characters
1614-maximum-nesting-depth-of-the-parentheses
1758-minimum-changes-to-make-alternating-binary-string
1781-sum-of-beauty-of-all-substrings
1784-check-if-binary-string-has-at-most-one-segment-of-ones
1888-minimum-number-of-flips-to-make-the-binary-string-alternating
1903-largest-odd-number-in-string
1980-find-unique-binary-string
2114-maximum-number-of-words-found-in-sentences
2315-count-asterisks
2515-shortest-distance-to-target-string-in-a-circular-array
3120-count-the-number-of-special-characters-i
3121-count-the-number-of-special-characters-ii
3325-count-substrings-with-k-frequency-characters-i
3499-maximize-active-section-with-trade-i
3517-smallest-palindromic-rearrangement-i
3612-process-string-with-special-operations-i
3838-weighted-word-mapping
3955-valid-binary-strings-with-cost-limit

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0239-sliding-window-maximum
0395-longest-substring-with-at-least-k-repeating-characters
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0713-subarray-product-less-than-k
0904-fruit-into-baskets
0930-binary-subarrays-with-sum
0992-subarrays-with-k-different-integers
1004-max-consecutive-ones-iii
1248-count-number-of-nice-subarrays
1358-number-of-substrings-containing-all-three-characters
1423-maximum-points-you-can-obtain-from-cards
1888-minimum-number-of-flips-to-make-the-binary-string-alternating
2302-count-subarrays-with-score-less-than-k
3325-count-substrings-with-k-frequency-characters-i

Counting

0169-majority-element
0229-majority-element-ii
0451-sort-characters-by-frequency
0992-subarrays-with-k-different-integers
1189-maximum-number-of-balloons
1781-sum-of-beauty-of-all-substrings
2006-count-number-of-pairs-with-absolute-difference-k

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0042-trapping-rain-water
0053-maximum-subarray
0070-climbing-stairs
0085-maximal-rectangle
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0131-palindrome-partitioning
0494-target-sum
0788-rotated-digits
1537-get-the-maximum-score
1888-minimum-number-of-flips-to-make-the-binary-string-alternating

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0047-permutations-ii
0051-n-queens
0052-n-queens-ii
0077-combinations
0078-subsets
0079-word-search
0090-subsets-ii
0131-palindrome-partitioning
0216-combination-sum-iii
0282-expression-add-operators
0494-target-sum
1980-find-unique-binary-string
3955-valid-binary-strings-with-cost-limit

Matrix

0037-sudoku-solver
0054-spiral-matrix
0073-set-matrix-zeroes
0079-word-search
0085-maximal-rectangle
1260-shift-2d-grid
1861-rotating-the-box
1886-determine-whether-matrix-can-be-obtained-by-rotation
2906-construct-product-matrix
2946-matrix-similarity-after-cyclic-shifts
3548-equal-sum-grid-partition-ii
3567-minimum-absolute-difference-in-sliding-submatrix
3643-flip-square-submatrix-vertically

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0303-range-sum-query-immutable
0560-subarray-sum-equals-k
0713-subarray-product-less-than-k
0930-binary-subarrays-with-sum
1004-max-consecutive-ones-iii
1248-count-number-of-nice-subarrays
1423-maximum-points-you-can-obtain-from-cards
1732-find-the-highest-altitude
2302-count-subarrays-with-score-less-than-k
2574-left-and-right-sum-differences
2906-construct-product-matrix
3548-equal-sum-grid-partition-ii

Design

0146-lru-cache
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0303-range-sum-query-immutable
0460-lfu-cache
0901-online-stock-span

Binary Search

0004-median-of-two-sorted-arrays
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0069-sqrtx
0153-find-minimum-in-rotated-sorted-array
0209-minimum-size-subarray-sum
0268-missing-number
0367-valid-perfect-square
0704-binary-search
0713-subarray-product-less-than-k
1004-max-consecutive-ones-iii
1498-number-of-subsequences-that-satisfy-the-given-sum-condition
1855-maximum-distance-between-a-pair-of-values
2302-count-subarrays-with-score-less-than-k
3477-fruits-into-baskets-ii

Enumeration

1291-sequential-digits
3499-maximize-active-section-with-trade-i
3548-equal-sum-grid-partition-ii
3955-valid-binary-strings-with-cost-limit

Simulation

0054-spiral-matrix
0258-add-digits
1260-shift-2d-grid
1929-concatenation-of-array
2553-separate-the-digits-in-an-array
2946-matrix-similarity-after-cyclic-shifts
3477-fruits-into-baskets-ii
3612-process-string-with-special-operations-i
3838-weighted-word-mapping
3867-sum-of-gcd-of-formed-pairs

Number Theory

0258-add-digits
1979-find-greatest-common-divisor-of-array
3658-gcd-of-odd-and-even-sums
3867-sum-of-gcd-of-formed-pairs

Recursion

0025-reverse-nodes-in-k-group
0050-powx-n
0060-permutation-sequence
0206-reverse-linked-list
0234-palindrome-linked-list
0326-power-of-three
0779-k-th-symbol-in-grammar
1922-count-good-numbers

Greedy

0011-container-with-most-water
0316-remove-duplicate-letters
0334-increasing-triplet-subsequence
0921-minimum-add-to-make-parentheses-valid
1081-smallest-subsequence-of-distinct-characters
1323-maximum-69-number
1537-get-the-maximum-score
1833-maximum-ice-cream-bars
1903-largest-odd-number-in-string
2078-two-furthest-houses-with-different-colors
2656-maximum-sum-with-exactly-k-elements
3689-maximum-total-subarray-value-i
3854-minimum-operations-to-make-array-parity-alternating

String Matching

0796-rotate-string

Bit Manipulation

0078-subsets
0090-subsets-ii
0268-missing-number
0645-set-mismatch
0779-k-th-symbol-in-grammar
3955-valid-binary-strings-with-cost-limit

Stack

0020-valid-parentheses
0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0316-remove-duplicate-letters
0496-next-greater-element-i
0503-next-greater-element-ii
0901-online-stock-span
0921-minimum-add-to-make-parentheses-valid
1021-remove-outermost-parentheses
1047-remove-all-adjacent-duplicates-in-string
1081-smallest-subsequence-of-distinct-characters
1209-remove-all-adjacent-duplicates-in-string-ii
1614-maximum-nesting-depth-of-the-parentheses

Trie

0014-longest-common-prefix

Bucket Sort

0451-sort-characters-by-frequency
0912-sort-an-array

Union-Find

0128-longest-consecutive-sequence

Merge Sort

0148-sort-list
0912-sort-an-array

Radix Sort

0912-sort-an-array

Counting Sort

0912-sort-an-array
1833-maximum-ice-cream-bars
3517-smallest-palindromic-rearrangement-i

Linked List

0019-remove-nth-node-from-end-of-list
0025-reverse-nodes-in-k-group
0061-rotate-list
0082-remove-duplicates-from-sorted-list-ii
0083-remove-duplicates-from-sorted-list
0092-reverse-linked-list-ii
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0148-sort-list
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0234-palindrome-linked-list
0328-odd-even-linked-list
0460-lfu-cache
0876-middle-of-the-linked-list
2058-find-the-minimum-and-maximum-number-of-nodes-between-critical-points
2095-delete-the-middle-node-of-a-linked-list

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0239-sliding-window-maximum

Depth-First Search

0079-word-search

Segment Tree

3477-fruits-into-baskets-ii

Ordered Set

3477-fruits-into-baskets-ii

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0316-remove-duplicate-letters
0496-next-greater-element-i
0503-next-greater-element-ii
0901-online-stock-span
1081-smallest-subsequence-of-distinct-characters

Memoization

0070-climbing-stairs

Monotonic Queue

0239-sliding-window-maximum

Data Stream

0901-online-stock-span

Doubly-Linked List

0146-lru-cache
0460-lfu-cache