LeetCode-Problems

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

LeetCode Topics

Array

0001-two-sum
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
0046-permutations
0053-maximum-subarray
0057-insert-interval
0078-subsets
0088-merge-sorted-array
0121-best-time-to-buy-and-sell-stock
0150-evaluate-reverse-polish-notation
0169-majority-element
0179-largest-number
0189-rotate-array
0200-number-of-islands
0217-contains-duplicate
0219-contains-duplicate-ii
0238-product-of-array-except-self
0283-move-zeroes
0303-range-sum-query-immutable
0456-132-pattern
0542-01-matrix
0560-subarray-sum-equals-k
0605-can-place-flowers
0643-maximum-average-subarray-i
0682-baseball-game
0724-find-pivot-index
0729-my-calendar-i
0731-my-calendar-ii
0733-flood-fill
0735-asteroid-collision
0792-binary-search
0841-shortest-distance-to-a-character
0859-design-circular-deque
0870-magic-squares-in-grid
0882-peak-index-in-a-mountain-array
0921-spiral-matrix-iii
0948-sort-an-array
1046-max-consecutive-ones-iii
1256-rank-transform-of-an-array
1319-unique-number-of-occurrences
1392-find-the-difference-of-two-arrays
1435-xor-queries-of-a-subarray
1477-product-of-the-last-k-numbers
1497-design-a-stack-with-increment-operation
1556-make-two-arrays-equal-by-reversing-subarrays
1580-shuffle-the-array
1586-longest-subarray-of-1s-after-deleting-one-element
1603-running-sum-of-1d-array
1615-range-sum-of-sorted-subarray-sums
1786-count-the-number-of-consistent-strings
1791-richest-customer-wealth
1798-max-number-of-k-sum-pairs
1833-find-the-highest-altitude
1878-check-if-array-is-sorted-and-rotated
2006-find-the-student-that-will-replace-the-chalk
2048-build-array-from-permutation
2058-concatenation-of-array
2163-kth-distinct-string-in-an-array
2392-successful-pairs-of-spells-and-potions
2494-sum-of-prefix-scores-of-strings
2503-longest-subarray-with-maximum-bitwise-and
2755-extra-characters-in-a-string
3329-find-the-length-of-the-longest-common-prefix
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3515-find-if-digit-game-can-be-won

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
0278-first-bad-version
0374-guess-number-higher-or-lower
0456-132-pattern
0729-my-calendar-i
0731-my-calendar-ii
0792-binary-search
0882-peak-index-in-a-mountain-array
1046-max-consecutive-ones-iii
1615-range-sum-of-sorted-subarray-sums
2006-find-the-student-that-will-replace-the-chalk
2392-successful-pairs-of-spells-and-potions

Math

0002-add-two-numbers
0009-palindrome-number
0013-roman-to-integer
0050-powx-n
0067-add-binary
0069-sqrtx
0150-evaluate-reverse-polish-notation
0189-rotate-array
0241-different-ways-to-add-parentheses
0263-ugly-number
0273-integer-to-english-words
0564-find-the-closest-palindrome
0592-fraction-addition-and-subtraction
0870-magic-squares-in-grid
1477-product-of-the-last-k-numbers
2812-find-the-maximum-achievable-number
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3515-find-if-digit-game-can-be-won

Two Pointers

0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0061-rotate-list
0086-partition-list
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0151-reverse-words-in-a-string
0189-rotate-array
0234-palindrome-linked-list
0283-move-zeroes
0344-reverse-string
0345-reverse-vowels-of-a-string
0392-is-subsequence
0443-string-compression
0841-shortest-distance-to-a-character
0874-backspace-string-compare
0908-middle-of-the-linked-list
1615-range-sum-of-sorted-subarray-sums
1798-max-number-of-k-sum-pairs
1894-merge-strings-alternately
2216-delete-the-middle-node-of-a-linked-list
2392-successful-pairs-of-spells-and-potions

String

0008-string-to-integer-atoi
0013-roman-to-integer
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0020-valid-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0067-add-binary
0125-valid-palindrome
0151-reverse-words-in-a-string
0179-largest-number
0214-shortest-palindrome
0241-different-ways-to-add-parentheses
0242-valid-anagram
0273-integer-to-english-words
0344-reverse-string
0345-reverse-vowels-of-a-string
0383-ransom-note
0387-first-unique-character-in-a-string
0392-is-subsequence
0409-longest-palindrome
0443-string-compression
0564-find-the-closest-palindrome
0592-fraction-addition-and-subtraction
0841-shortest-distance-to-a-character
0874-backspace-string-compare
1320-remove-all-adjacent-duplicates-in-string-ii
1473-find-the-longest-substring-containing-vowels-in-even-counts
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1786-count-the-number-of-consistent-strings
1894-merge-strings-alternately
1987-substrings-of-size-three-with-distinct-characters
2076-sum-of-digits-of-string-after-convert
2163-kth-distinct-string-in-an-array
2470-removing-stars-from-a-string
2494-sum-of-prefix-scores-of-strings
2755-extra-characters-in-a-string
3329-find-the-length-of-the-longest-common-prefix
3412-permutation-difference-between-two-strings

Greedy

0179-largest-number
0409-longest-palindrome
0605-can-place-flowers

Prefix Sum

0238-product-of-array-except-self
0303-range-sum-query-immutable
0560-subarray-sum-equals-k
0724-find-pivot-index
0731-my-calendar-ii
1046-max-consecutive-ones-iii
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1603-running-sum-of-1d-array
1833-find-the-highest-altitude
2006-find-the-student-that-will-replace-the-chalk

Sorting

0015-3sum
0088-merge-sorted-array
0148-sort-list
0169-majority-element
0179-largest-number
0217-contains-duplicate
0242-valid-anagram
0948-sort-an-array
1256-rank-transform-of-an-array
1556-make-two-arrays-equal-by-reversing-subarrays
1615-range-sum-of-sorted-subarray-sums
1798-max-number-of-k-sum-pairs
2392-successful-pairs-of-spells-and-potions

Hash Table

0001-two-sum
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0169-majority-element
0217-contains-duplicate
0219-contains-duplicate-ii
0242-valid-anagram
0383-ransom-note
0387-first-unique-character-in-a-string
0409-longest-palindrome
0432-all-oone-data-structure
0560-subarray-sum-equals-k
0870-magic-squares-in-grid
1256-rank-transform-of-an-array
1319-unique-number-of-occurrences
1392-find-the-difference-of-two-arrays
1473-find-the-longest-substring-containing-vowels-in-even-counts
1556-make-two-arrays-equal-by-reversing-subarrays
1786-count-the-number-of-consistent-strings
1798-max-number-of-k-sum-pairs
1987-substrings-of-size-three-with-distinct-characters
2163-kth-distinct-string-in-an-array
2755-extra-characters-in-a-string
3329-find-the-length-of-the-longest-common-prefix
3412-permutation-difference-between-two-strings

Sliding Window

0219-contains-duplicate-ii
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
1987-substrings-of-size-three-with-distinct-characters

Dynamic Programming

0053-maximum-subarray
0121-best-time-to-buy-and-sell-stock
0241-different-ways-to-add-parentheses
0392-is-subsequence
0542-01-matrix
1586-longest-subarray-of-1s-after-deleting-one-element
2755-extra-characters-in-a-string

Backtracking

0017-letter-combinations-of-a-phone-number
0046-permutations
0078-subsets

Bit Manipulation

0067-add-binary
0078-subsets
0476-number-complement
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1786-count-the-number-of-consistent-strings
2323-minimum-bit-flips-to-convert-number
2503-longest-subarray-with-maximum-bitwise-and

Divide and Conquer

0053-maximum-subarray
0148-sort-list
0169-majority-element
0948-sort-an-array

Heap (Priority Queue)

0948-sort-an-array

Merge Sort

0148-sort-list
0948-sort-an-array

Bucket Sort

0948-sort-an-array

Radix Sort

0948-sort-an-array

Counting Sort

0169-majority-element
0383-ransom-note
0387-first-unique-character-in-a-string
0948-sort-an-array
1786-count-the-number-of-consistent-strings
1987-substrings-of-size-three-with-distinct-characters
2163-kth-distinct-string-in-an-array
2494-sum-of-prefix-scores-of-strings

Linked List

0002-add-two-numbers
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group
0061-rotate-list
0083-remove-duplicates-from-sorted-list
0086-partition-list
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0206-reverse-linked-list
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0432-all-oone-data-structure
0725-split-linked-list-in-parts
0859-design-circular-deque
0908-middle-of-the-linked-list
2216-delete-the-middle-node-of-a-linked-list

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group
0050-powx-n
0206-reverse-linked-list
0234-palindrome-linked-list
0241-different-ways-to-add-parentheses
0273-integer-to-english-words

Interactive

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

Stack

0020-valid-parentheses
0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0150-evaluate-reverse-polish-notation
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0456-132-pattern
0682-baseball-game
0735-asteroid-collision
0776-n-ary-tree-postorder-traversal
0874-backspace-string-compare
1320-remove-all-adjacent-duplicates-in-string-ii
1497-design-a-stack-with-increment-operation
2470-removing-stars-from-a-string

Simulation

0067-add-binary
0592-fraction-addition-and-subtraction
0682-baseball-game
0735-asteroid-collision
0874-backspace-string-compare
0921-spiral-matrix-iii
2006-find-the-student-that-will-replace-the-chalk
2048-build-array-from-permutation
2058-concatenation-of-array
2076-sum-of-digits-of-string-after-convert
2470-removing-stars-from-a-string

Matrix

0200-number-of-islands
0542-01-matrix
0733-flood-fill
0870-magic-squares-in-grid
0921-spiral-matrix-iii
1791-richest-customer-wealth

Tree

0094-binary-tree-inorder-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0543-diameter-of-binary-tree
0776-n-ary-tree-postorder-traversal
1079-sum-of-root-to-leaf-binary-numbers

Depth-First Search

0094-binary-tree-inorder-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0200-number-of-islands
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0543-diameter-of-binary-tree
0733-flood-fill
0776-n-ary-tree-postorder-traversal
1079-sum-of-root-to-leaf-binary-numbers

Binary Tree

0094-binary-tree-inorder-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0543-diameter-of-binary-tree
1079-sum-of-root-to-leaf-binary-numbers

Trie

0014-longest-common-prefix
0440-k-th-smallest-in-lexicographical-order
2494-sum-of-prefix-scores-of-strings
2755-extra-characters-in-a-string
3329-find-the-length-of-the-longest-common-prefix

Monotonic Stack

0456-132-pattern

Ordered Set

0456-132-pattern
0729-my-calendar-i
0731-my-calendar-ii

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
0214-shortest-palindrome

Queue

0232-implement-queue-using-stacks
0387-first-unique-character-in-a-string
0859-design-circular-deque
1477-product-of-the-last-k-numbers

Design

0232-implement-queue-using-stacks
0303-range-sum-query-immutable
0432-all-oone-data-structure
0729-my-calendar-i
0731-my-calendar-ii
0859-design-circular-deque
1477-product-of-the-last-k-numbers
1497-design-a-stack-with-increment-operation

Data Stream

1477-product-of-the-last-k-numbers

Brainteaser

2503-longest-subarray-with-maximum-bitwise-and

Memoization

0241-different-ways-to-add-parentheses

Rolling Hash

0214-shortest-palindrome

Hash Function

0214-shortest-palindrome

Breadth-First Search

0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0200-number-of-islands
0226-invert-binary-tree
0542-01-matrix
0733-flood-fill

Segment Tree

0729-my-calendar-i
0731-my-calendar-ii

Doubly-Linked List

0432-all-oone-data-structure

Graph

1916-find-center-of-star-graph

Binary Search Tree

0235-lowest-common-ancestor-of-a-binary-search-tree

Union Find

0200-number-of-islands