LeetCode

Collection of LeetCode questions to ace the coding interview! - Created using LeetHub v3

LeetCode Topics

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0036-valid-sudoku
0049-group-anagrams
0128-longest-consecutive-sequence
0217-contains-duplicate
0219-contains-duplicate-ii
0242-valid-anagram
0347-top-k-frequent-elements
0424-longest-repeating-character-replacement
0535-encode-and-decode-tinyurl
0567-permutation-in-string
0763-partition-labels
0981-time-based-key-value-store
1365-how-many-numbers-are-smaller-than-the-current-number
1387-find-elements-in-a-contaminated-binary-tree
1786-count-the-number-of-consistent-strings
1876-substrings-of-size-three-with-distinct-characters
2300-construct-string-with-repeat-limit
2367-number-of-arithmetic-triplets
2570-merge-two-2d-arrays-by-summing-values
2744-find-maximum-number-of-string-pairs
2799-count-complete-subarrays-in-an-array
2932-maximum-strong-pair-xor-i
3146-permutation-difference-between-two-strings
3318-find-x-sum-of-all-k-long-subarrays-i
3541-find-most-frequent-vowel-and-consonant
3581-the-two-sneaky-numbers-of-digitville
4008-restore-finishing-order

String

0003-longest-substring-without-repeating-characters
0020-valid-parentheses
0049-group-anagrams
0125-valid-palindrome
0242-valid-anagram
0424-longest-repeating-character-replacement
0535-encode-and-decode-tinyurl
0567-permutation-in-string
0763-partition-labels
0942-di-string-match
0981-time-based-key-value-store
1636-number-of-substrings-with-only-1s
1768-merge-strings-alternately
1786-count-the-number-of-consistent-strings
1807-partitioning-into-minimum-number-of-deci-binary-numbers
1876-substrings-of-size-three-with-distinct-characters
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
2108-find-first-palindromic-string-in-the-array
2120-execution-of-all-suffix-instructions-staying-in-a-grid
2137-final-value-of-variable-after-performing-operations
2300-construct-string-with-repeat-limit
2697-lexicographically-smallest-palindrome
2744-find-maximum-number-of-string-pairs
3146-permutation-difference-between-two-strings
3174-clear-digits
3194-find-words-containing-character
3258-count-substrings-that-satisfy-k-constraint-i
3271-hash-divided-string
3379-score-of-a-string
3461-check-if-digits-are-equal-in-string-after-operations-i
3498-reverse-degree-of-a-string
3541-find-most-frequent-vowel-and-consonant
3794-reverse-string-prefix
3823-reverse-letters-then-special-characters-in-a-string
3838-weighted-word-mapping

Greedy

0011-container-with-most-water
0763-partition-labels
0942-di-string-match
1285-balance-a-binary-search-tree
1807-partitioning-into-minimum-number-of-deci-binary-numbers
1877-minimize-maximum-pair-sum-in-array
2148-minimum-number-of-moves-to-seat-everyone
2300-construct-string-with-repeat-limit
2697-lexicographically-smallest-palindrome

Heap (Priority Queue)

0347-top-k-frequent-elements
0373-find-k-pairs-with-smallest-sums
1464-maximum-product-of-two-elements-in-an-array
2300-construct-string-with-repeat-limit
2500-delete-greatest-value-in-each-row
2553-total-cost-to-hire-k-workers
2974-minimum-number-game
3264-final-array-state-after-k-multiplication-operations-i
3318-find-x-sum-of-all-k-long-subarrays-i

Counting

0347-top-k-frequent-elements
1603-design-parking-system
1786-count-the-number-of-consistent-strings
1876-substrings-of-size-three-with-distinct-characters
2300-construct-string-with-repeat-limit
3541-find-most-frequent-vowel-and-consonant
3778-transform-array-by-parity

Array

0001-two-sum
0011-container-with-most-water
0015-3sum
0033-search-in-rotated-sorted-array
0036-valid-sudoku
0042-trapping-rain-water
0049-group-anagrams
0074-search-a-2d-matrix
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0150-evaluate-reverse-polish-notation
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0198-house-robber
0217-contains-duplicate
0219-contains-duplicate-ii
0238-product-of-array-except-self
0300-longest-increasing-subsequence
0322-coin-change
0347-top-k-frequent-elements
0373-find-k-pairs-with-smallest-sums
0704-binary-search
0739-daily-temperatures
0747-min-cost-climbing-stairs
0832-flipping-an-image
0853-car-fleet
0875-koko-eating-bananas
0942-di-string-match
0950-reveal-cards-in-increasing-order
1277-count-square-submatrices-with-all-ones
1365-how-many-numbers-are-smaller-than-the-current-number
1389-create-target-array-in-the-given-order
1402-count-square-submatrices-with-all-ones
1464-maximum-product-of-two-elements-in-an-array
1652-defuse-the-bomb
1755-defuse-the-bomb
1786-count-the-number-of-consistent-strings
1823-find-the-winner-of-the-circular-game
1877-minimize-maximum-pair-sum-in-array
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
2048-build-array-from-permutation
2058-concatenation-of-array
2108-find-first-palindromic-string-in-the-array
2137-final-value-of-variable-after-performing-operations
2148-minimum-number-of-moves-to-seat-everyone
2149-rearrange-array-elements-by-sign
2161-partition-array-according-to-given-pivot
2221-find-triangular-sum-of-an-array
2326-spiral-matrix-iv
2367-number-of-arithmetic-triplets
2482-difference-between-ones-and-zeros-in-row-and-column
2500-delete-greatest-value-in-each-row
2553-total-cost-to-hire-k-workers
2570-merge-two-2d-arrays-by-summing-values
2744-find-maximum-number-of-string-pairs
2799-count-complete-subarrays-in-an-array
2932-maximum-strong-pair-xor-i
2974-minimum-number-game
3194-find-words-containing-character
3194-minimum-average-of-smallest-and-largest-elements
3264-final-array-state-after-k-multiplication-operations-i
3318-find-x-sum-of-all-k-long-subarrays-i
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3512-minimum-operations-to-make-array-sum-divisible-by-k
3581-the-two-sneaky-numbers-of-digitville
3643-flip-square-submatrix-vertically
3688-bitwise-or-of-even-numbers-in-an-array
3701-compute-alternating-sum
3778-transform-array-by-parity
3838-weighted-word-mapping
4008-restore-finishing-order

Two Pointers

0011-container-with-most-water
0015-3sum
0042-trapping-rain-water
0125-valid-palindrome
0167-two-sum-ii-input-array-is-sorted
0567-permutation-in-string
0763-partition-labels
0832-flipping-an-image
0876-middle-of-the-linked-list
0942-di-string-match
1768-merge-strings-alternately
1877-minimize-maximum-pair-sum-in-array
2108-find-first-palindromic-string-in-the-array
2130-maximum-twin-sum-of-a-linked-list
2149-rearrange-array-elements-by-sign
2161-partition-array-according-to-given-pivot
2367-number-of-arithmetic-triplets
2553-total-cost-to-hire-k-workers
2570-merge-two-2d-arrays-by-summing-values
2697-lexicographically-smallest-palindrome
3194-minimum-average-of-smallest-and-largest-elements
3643-flip-square-submatrix-vertically
3794-reverse-string-prefix
3823-reverse-letters-then-special-characters-in-a-string

Simulation

0832-flipping-an-image
0950-reveal-cards-in-increasing-order
1389-create-target-array-in-the-given-order
1603-design-parking-system
1688-count-of-matches-in-tournament
1823-find-the-winner-of-the-circular-game
2048-build-array-from-permutation
2058-concatenation-of-array
2120-execution-of-all-suffix-instructions-staying-in-a-grid
2137-final-value-of-variable-after-performing-operations
2149-rearrange-array-elements-by-sign
2161-partition-array-according-to-given-pivot
2181-merge-nodes-in-between-zeros
2221-find-triangular-sum-of-an-array
2326-spiral-matrix-iv
2482-difference-between-ones-and-zeros-in-row-and-column
2500-delete-greatest-value-in-each-row
2553-total-cost-to-hire-k-workers
2744-find-maximum-number-of-string-pairs
2974-minimum-number-game
3174-clear-digits
3264-final-array-state-after-k-multiplication-operations-i
3271-hash-divided-string
3461-check-if-digits-are-equal-in-string-after-operations-i
3498-reverse-degree-of-a-string
3688-bitwise-or-of-even-numbers-in-an-array
3701-compute-alternating-sum
3823-reverse-letters-then-special-characters-in-a-string
3838-weighted-word-mapping

Tree

0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0112-path-sum
0930-all-possible-full-binary-trees
0975-range-sum-of-bst
1114-binary-search-tree-to-greater-sum-tree
1243-sum-of-nodes-with-even-valued-grandparent
1285-balance-a-binary-search-tree
1387-find-elements-in-a-contaminated-binary-tree
1498-find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree
2347-count-nodes-equal-to-average-of-subtree
2493-reverse-odd-levels-of-binary-tree

Depth-First Search

0104-maximum-depth-of-binary-tree
0112-path-sum
0813-all-paths-from-source-to-target
0975-range-sum-of-bst
1114-binary-search-tree-to-greater-sum-tree
1243-sum-of-nodes-with-even-valued-grandparent
1285-balance-a-binary-search-tree
1387-find-elements-in-a-contaminated-binary-tree
1498-find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree
2347-count-nodes-equal-to-average-of-subtree
2493-reverse-odd-levels-of-binary-tree

Breadth-First Search

0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0112-path-sum
0322-coin-change
0813-all-paths-from-source-to-target
1243-sum-of-nodes-with-even-valued-grandparent
1387-find-elements-in-a-contaminated-binary-tree
1498-find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree
2493-reverse-odd-levels-of-binary-tree

Binary Tree

0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0112-path-sum
0930-all-possible-full-binary-trees
0975-range-sum-of-bst
1114-binary-search-tree-to-greater-sum-tree
1243-sum-of-nodes-with-even-valued-grandparent
1285-balance-a-binary-search-tree
1387-find-elements-in-a-contaminated-binary-tree
1498-find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree
2347-count-nodes-equal-to-average-of-subtree
2493-reverse-odd-levels-of-binary-tree

Binary Search Tree

0033-search-in-rotated-sorted-array
0074-search-a-2d-matrix
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0300-longest-increasing-subsequence
0704-binary-search
0875-koko-eating-bananas
0975-range-sum-of-bst
0981-time-based-key-value-store
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Divide and Conquer

0347-top-k-frequent-elements
1285-balance-a-binary-search-tree

Design

0155-min-stack
0535-encode-and-decode-tinyurl
0981-time-based-key-value-store
1387-find-elements-in-a-contaminated-binary-tree
1603-design-parking-system

Prefix Sum

0238-product-of-array-except-self
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Backtracking

0813-all-paths-from-source-to-target

Graph

0813-all-paths-from-source-to-target

Math

0002-add-two-numbers
0070-climbing-stairs
0150-evaluate-reverse-polish-notation
1290-convert-binary-number-in-a-linked-list-to-integer
1636-number-of-substrings-with-only-1s
1688-count-of-matches-in-tournament
1761-count-sorted-vowel-strings
1823-find-the-winner-of-the-circular-game
2221-find-triangular-sum-of-an-array
2556-convert-the-temperature
2807-insert-greatest-common-divisors-in-linked-list
2812-find-the-maximum-achievable-number
3172-divisible-and-non-divisible-sums-difference
3264-final-array-state-after-k-multiplication-operations-i
3461-check-if-digits-are-equal-in-string-after-operations-i
3512-minimum-operations-to-make-array-sum-divisible-by-k
3581-the-two-sneaky-numbers-of-digitville
3676-smallest-number-with-all-set-bits

Dynamic Programming

0042-trapping-rain-water
0070-climbing-stairs
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0198-house-robber
0300-longest-increasing-subsequence
0322-coin-change
0338-counting-bits
0747-min-cost-climbing-stairs
0930-all-possible-full-binary-trees
1277-count-square-submatrices-with-all-ones
1402-count-square-submatrices-with-all-ones
1761-count-sorted-vowel-strings

Bit Manipulation

0338-counting-bits
0832-flipping-an-image
1786-count-the-number-of-consistent-strings
2932-maximum-strong-pair-xor-i
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3676-smallest-number-with-all-set-bits
3688-bitwise-or-of-even-numbers-in-an-array

Memoization

0070-climbing-stairs
0930-all-possible-full-binary-trees

Sorting

0015-3sum
0049-group-anagrams
0217-contains-duplicate
0242-valid-anagram
0347-top-k-frequent-elements
0853-car-fleet
0950-reveal-cards-in-increasing-order
1365-how-many-numbers-are-smaller-than-the-current-number
1464-maximum-product-of-two-elements-in-an-array
1877-minimize-maximum-pair-sum-in-array
2148-minimum-number-of-moves-to-seat-everyone
2500-delete-greatest-value-in-each-row
2974-minimum-number-game
3194-minimum-average-of-smallest-and-largest-elements
3778-transform-array-by-parity

Linked List

0002-add-two-numbers
0021-merge-two-sorted-lists
0206-reverse-linked-list
0237-delete-node-in-a-linked-list
0876-middle-of-the-linked-list
1290-convert-binary-number-in-a-linked-list-to-integer
1669-merge-in-between-linked-lists
2130-maximum-twin-sum-of-a-linked-list
2181-merge-nodes-in-between-zeros
2326-spiral-matrix-iv
2807-insert-greatest-common-divisors-in-linked-list

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0206-reverse-linked-list
0930-all-possible-full-binary-trees
1823-find-the-winner-of-the-circular-game

Matrix

0036-valid-sudoku
0074-search-a-2d-matrix
0832-flipping-an-image
1277-count-square-submatrices-with-all-ones
1402-count-square-submatrices-with-all-ones
2326-spiral-matrix-iv
2482-difference-between-ones-and-zeros-in-row-and-column
2500-delete-greatest-value-in-each-row
3643-flip-square-submatrix-vertically

Combinatorics

1761-count-sorted-vowel-strings
2221-find-triangular-sum-of-an-array
3461-check-if-digits-are-equal-in-string-after-operations-i

Queue

0950-reveal-cards-in-increasing-order
1823-find-the-winner-of-the-circular-game
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Sliding Window

0003-longest-substring-without-repeating-characters
0219-contains-duplicate-ii
0424-longest-repeating-character-replacement
0567-permutation-in-string
1652-defuse-the-bomb
1755-defuse-the-bomb
1876-substrings-of-size-three-with-distinct-characters
2799-count-complete-subarrays-in-an-array
2932-maximum-strong-pair-xor-i
3258-count-substrings-that-satisfy-k-constraint-i
3318-find-x-sum-of-all-k-long-subarrays-i
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Counting Sort

1365-how-many-numbers-are-smaller-than-the-current-number
2148-minimum-number-of-moves-to-seat-everyone

Bucket Sort

0347-top-k-frequent-elements

Quickselect

0347-top-k-frequent-elements

Hash Function

0535-encode-and-decode-tinyurl

Union Find

0128-longest-consecutive-sequence

Stack

0020-valid-parentheses
0042-trapping-rain-water
0150-evaluate-reverse-polish-notation
0155-min-stack
0739-daily-temperatures
0853-car-fleet
2130-maximum-twin-sum-of-a-linked-list
3174-clear-digits

Monotonic Stack

0042-trapping-rain-water
0739-daily-temperatures
0853-car-fleet

Number Theory

2221-find-triangular-sum-of-an-array
2807-insert-greatest-common-divisors-in-linked-list
3461-check-if-digits-are-equal-in-string-after-operations-i

Enumeration

2367-number-of-arithmetic-triplets

Trie

2932-maximum-strong-pair-xor-i