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

LeetCode Topics

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0029-divide-two-integers
1146-greatest-common-divisor-of-strings
1500-count-largest-group
2415-count-the-number-of-ideal-arrays
2704-maximum-difference-by-remapping-a-digit
3172-divisible-and-non-divisible-sums-difference
3321-type-of-triangle
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0006-zigzag-conversion
0008-string-to-integer-atoi
0010-regular-expression-matching
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
0028-find-the-index-of-the-first-occurrence-in-a-string
0030-substring-with-concatenation-of-all-words
0038-count-and-say
0151-reverse-words-in-a-string
0345-reverse-vowels-of-a-string
0868-push-dominoes
1058-lexicographically-smallest-equivalent-string
1146-greatest-common-divisor-of-strings
1894-merge-strings-alternately
2237-longest-palindrome-by-concatenating-two-letter-words
2422-query-kth-smallest-trimmed-number
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3194-find-words-containing-character
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations
3683-find-the-lexicographically-largest-string-from-the-box-i
3753-maximum-difference-between-even-and-odd-frequency-i
3761-maximum-difference-between-even-and-odd-frequency-ii

Dynamic Programming

0005-longest-palindromic-substring
0010-regular-expression-matching
0022-generate-parentheses
0868-push-dominoes
1986-largest-color-value-in-a-directed-graph
2061-painting-a-grid-with-three-different-colors
2415-count-the-number-of-ideal-arrays
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3307-find-the-maximum-sum-of-node-values
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations

Combinatorics

2415-count-the-number-of-ideal-arrays
3637-count-number-of-balanced-permutations

Number Theory

2415-count-the-number-of-ideal-arrays

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0036-valid-sudoku
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0073-set-matrix-zeroes
0075-sort-colors
0135-candy
0164-maximum-gap
0605-can-place-flowers
0948-sort-an-array
1293-three-consecutive-odds
1424-maximum-candies-you-can-get-from-boxes
1528-kids-with-the-greatest-number-of-candies
2048-build-array-from-permutation
2144-maximum-difference-between-increasing-elements
2180-maximum-number-of-tasks-you-can-assign
2215-finding-3-digit-even-numbers
2237-longest-palindrome-by-concatenating-two-letter-words
2394-count-subarrays-with-score-less-than-k
2422-query-kth-smallest-trimmed-number
2856-count-complete-subarrays-in-an-array
2915-count-of-interesting-subarrays
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3194-find-words-containing-character
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3639-zero-array-transformation-i
3647-zero-array-transformation-iii

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
0030-substring-with-concatenation-of-all-words
0036-valid-sudoku
0037-sudoku-solver
0073-set-matrix-zeroes
1500-count-largest-group
1986-largest-color-value-in-a-directed-graph
2215-finding-3-digit-even-numbers
2237-longest-palindrome-by-concatenating-two-letter-words
2856-count-complete-subarrays-in-an-array
2915-count-of-interesting-subarrays
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3753-maximum-difference-between-even-and-odd-frequency-i

Sliding Window

0003-longest-substring-without-repeating-characters
0030-substring-with-concatenation-of-all-words
2394-count-subarrays-with-score-less-than-k
2856-count-complete-subarrays-in-an-array
3761-maximum-difference-between-even-and-odd-frequency-ii

Prefix Sum

2394-count-subarrays-with-score-less-than-k
2915-count-of-interesting-subarrays
3639-zero-array-transformation-i
3647-zero-array-transformation-iii
3761-maximum-difference-between-even-and-odd-frequency-ii

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group

Recursion

0002-add-two-numbers
0010-regular-expression-matching
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
2180-maximum-number-of-tasks-you-can-assign
2394-count-subarrays-with-score-less-than-k

Divide and Conquer

0004-median-of-two-sorted-arrays
0023-merge-k-sorted-lists
0948-sort-an-array
2422-query-kth-smallest-trimmed-number

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0031-next-permutation
0075-sort-colors
0151-reverse-words-in-a-string
0345-reverse-vowels-of-a-string
0868-push-dominoes
1894-merge-strings-alternately
3683-find-the-lexicographically-largest-string-from-the-box-i

Greedy

0011-container-with-most-water
0135-candy
0605-can-place-flowers
2180-maximum-number-of-tasks-you-can-assign
2237-longest-palindrome-by-concatenating-two-letter-words
2704-maximum-difference-by-remapping-a-digit
3143-longest-unequal-adjacent-groups-subsequence-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3307-find-the-maximum-sum-of-node-values
3647-zero-array-transformation-iii

Trie

0014-longest-common-prefix

Sorting

0015-3sum
0016-3sum-closest
0018-4sum
0075-sort-colors
0164-maximum-gap
0948-sort-an-array
2180-maximum-number-of-tasks-you-can-assign
2215-finding-3-digit-even-numbers
2422-query-kth-smallest-trimmed-number
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3647-zero-array-transformation-iii

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii

Queue

2180-maximum-number-of-tasks-you-can-assign

Monotonic Queue

2180-maximum-number-of-tasks-you-can-assign

Stack

0020-valid-parentheses

Bucket Sort

0164-maximum-gap
0948-sort-an-array

Radix Sort

0164-maximum-gap
0948-sort-an-array
2422-query-kth-smallest-trimmed-number

Heap (Priority Queue)

0023-merge-k-sorted-lists
0948-sort-an-array
2422-query-kth-smallest-trimmed-number
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3647-zero-array-transformation-iii

Merge Sort

0023-merge-k-sorted-lists
0948-sort-an-array

Counting Sort

0948-sort-an-array
1986-largest-color-value-in-a-directed-graph
2237-longest-palindrome-by-concatenating-two-letter-words
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3753-maximum-difference-between-even-and-odd-frequency-i

Quickselect

2422-query-kth-smallest-trimmed-number

Simulation

2048-build-array-from-permutation

Graph

1424-maximum-candies-you-can-get-from-boxes
1986-largest-color-value-in-a-directed-graph
2438-find-closest-node-to-given-two-nodes
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Matrix

0036-valid-sudoku
0037-sudoku-solver
0073-set-matrix-zeroes
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Shortest Path

3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string

Bit Manipulation

0029-divide-two-integers
3307-find-the-maximum-sum-of-node-values

Enumeration

2215-finding-3-digit-even-numbers
3683-find-the-lexicographically-largest-string-from-the-box-i
3761-maximum-difference-between-even-and-odd-frequency-ii

Tree

3307-find-the-maximum-sum-of-node-values
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Topological Sort

1986-largest-color-value-in-a-directed-graph

Memoization

1986-largest-color-value-in-a-directed-graph

Depth-First Search

2438-find-closest-node-to-given-two-nodes
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Breadth-First Search

1424-maximum-candies-you-can-get-from-boxes
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Union Find

1058-lexicographically-smallest-equivalent-string