Leetcode

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

LeetCode Topics

Two Pointers

0016-3sum-closest
0031-next-permutation
0080-remove-duplicates-from-sorted-array-ii
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0349-intersection-of-two-arrays
0392-is-subsequence
0532-k-diff-pairs-in-an-array
0611-valid-triangle-number

String

0008-string-to-integer-atoi
0012-integer-to-roman
0032-longest-valid-parentheses
0151-reverse-words-in-a-string
0187-repeated-dna-sequences
0205-isomorphic-strings
0290-word-pattern
0383-ransom-note
0392-is-subsequence
0394-decode-string
0412-fizz-buzz
1353-find-resultant-array-after-removing-anagrams
1987-substrings-of-size-three-with-distinct-characters

Dynamic Programming

0032-longest-valid-parentheses
0122-best-time-to-buy-and-sell-stock-ii
0392-is-subsequence
0747-min-cost-climbing-stairs
1013-fibonacci-number

Array

0001-two-sum
0016-3sum-closest
0031-next-permutation
0041-first-missing-positive
0048-rotate-image
0080-remove-duplicates-from-sorted-array-ii
0122-best-time-to-buy-and-sell-stock-ii
0128-longest-consecutive-sequence
0134-gas-station
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0204-count-primes
0209-minimum-size-subarray-sum
0215-kth-largest-element-in-an-array
0228-summary-ranges
0274-h-index
0304-range-sum-query-2d-immutable
0349-intersection-of-two-arrays
0442-find-all-duplicates-in-an-array
0448-find-all-numbers-disappeared-in-an-array
0532-k-diff-pairs-in-an-array
0560-subarray-sum-equals-k
0611-valid-triangle-number
0643-maximum-average-subarray-i
0713-subarray-product-less-than-k
0735-asteroid-collision
0747-min-cost-climbing-stairs
0830-largest-triangle-area
0898-transpose-matrix
0940-fruit-into-baskets
0948-sort-an-array
1018-largest-perimeter-triangle
1324-where-will-the-ball-fall
1353-find-resultant-array-after-removing-anagrams
1677-matrix-diagonal-sum
2324-find-triangular-sum-of-an-array
2552-maximum-sum-of-distinct-subarrays-with-length-k

Hash Table

0001-two-sum
0012-integer-to-roman
0041-first-missing-positive
0128-longest-consecutive-sequence
0187-repeated-dna-sequences
0205-isomorphic-strings
0290-word-pattern
0349-intersection-of-two-arrays
0383-ransom-note
0442-find-all-duplicates-in-an-array
0448-find-all-numbers-disappeared-in-an-array
0532-k-diff-pairs-in-an-array
0560-subarray-sum-equals-k
0940-fruit-into-baskets
1353-find-resultant-array-after-removing-anagrams
1987-substrings-of-size-three-with-distinct-characters
2552-maximum-sum-of-distinct-subarrays-with-length-k

Prefix Sum

0209-minimum-size-subarray-sum
0304-range-sum-query-2d-immutable
0560-subarray-sum-equals-k
0713-subarray-product-less-than-k

Binary Search

0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0222-count-complete-tree-nodes
0349-intersection-of-two-arrays
0532-k-diff-pairs-in-an-array
0611-valid-triangle-number
0713-subarray-product-less-than-k

Greedy

0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0611-valid-triangle-number
1018-largest-perimeter-triangle

Sorting

0016-3sum-closest
0215-kth-largest-element-in-an-array
0274-h-index
0349-intersection-of-two-arrays
0532-k-diff-pairs-in-an-array
0611-valid-triangle-number
0948-sort-an-array
1018-largest-perimeter-triangle
1353-find-resultant-array-after-removing-anagrams

Sliding Window

0187-repeated-dna-sequences
0209-minimum-size-subarray-sum
0643-maximum-average-subarray-i
0713-subarray-product-less-than-k
0940-fruit-into-baskets
1987-substrings-of-size-three-with-distinct-characters
2552-maximum-sum-of-distinct-subarrays-with-length-k

Math

0012-integer-to-roman
0048-rotate-image
0050-powx-n
0172-factorial-trailing-zeroes
0189-rotate-array
0204-count-primes
0412-fizz-buzz
0830-largest-triangle-area
1013-fibonacci-number
1018-largest-perimeter-triangle
1642-water-bottles
2324-find-triangular-sum-of-an-array
3336-water-bottles-ii

Geometry

0830-largest-triangle-area

Tree

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0107-binary-tree-level-order-traversal-ii
0111-minimum-depth-of-binary-tree
0112-path-sum
0144-binary-tree-preorder-traversal
0222-count-complete-tree-nodes
0226-invert-binary-tree
0530-minimum-absolute-difference-in-bst
0543-diameter-of-binary-tree
0637-average-of-levels-in-binary-tree

Depth-First Search

0100-same-tree
0101-symmetric-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0144-binary-tree-preorder-traversal
0226-invert-binary-tree
0530-minimum-absolute-difference-in-bst
0543-diameter-of-binary-tree
0637-average-of-levels-in-binary-tree

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0107-binary-tree-level-order-traversal-ii
0111-minimum-depth-of-binary-tree
0112-path-sum
0226-invert-binary-tree
0530-minimum-absolute-difference-in-bst
0637-average-of-levels-in-binary-tree

Binary Tree

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0107-binary-tree-level-order-traversal-ii
0111-minimum-depth-of-binary-tree
0112-path-sum
0144-binary-tree-preorder-traversal
0222-count-complete-tree-nodes
0226-invert-binary-tree
0530-minimum-absolute-difference-in-bst
0543-diameter-of-binary-tree
0637-average-of-levels-in-binary-tree

Bit Manipulation

0187-repeated-dna-sequences
0222-count-complete-tree-nodes

Binary Search Tree

0530-minimum-absolute-difference-in-bst

Counting

0383-ransom-note
1987-substrings-of-size-three-with-distinct-characters

Counting Sort

0274-h-index
0948-sort-an-array

Divide and Conquer

0215-kth-largest-element-in-an-array
0948-sort-an-array

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0948-sort-an-array

Quickselect

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

Simulation

0412-fizz-buzz
0735-asteroid-collision
0898-transpose-matrix
1324-where-will-the-ball-fall
1642-water-bottles
2324-find-triangular-sum-of-an-array
3336-water-bottles-ii

Combinatorics

2324-find-triangular-sum-of-an-array

Union Find

0128-longest-consecutive-sequence

Enumeration

0204-count-primes
1212-sequential-digits

Stack

0032-longest-valid-parentheses
0144-binary-tree-preorder-traversal
0394-decode-string
0735-asteroid-collision

Recursion

0050-powx-n
0203-remove-linked-list-elements
0394-decode-string
1013-fibonacci-number

Merge Sort

0948-sort-an-array

Bucket Sort

0948-sort-an-array

Radix Sort

0948-sort-an-array

Matrix

0048-rotate-image
0304-range-sum-query-2d-immutable
0898-transpose-matrix
1324-where-will-the-ball-fall
1677-matrix-diagonal-sum

Design

0304-range-sum-query-2d-immutable

Memoization

1013-fibonacci-number

Rolling Hash

0187-repeated-dna-sequences

Hash Function

0187-repeated-dna-sequences

Linked List

0203-remove-linked-list-elements

Number Theory

0204-count-primes