leetcode-solutions

My Leetcode Solutions

LeetCode Topics

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0013-roman-to-integer
0050-powx-n
0066-plus-one
0069-sqrtx
0231-power-of-two
0268-missing-number
0371-sum-of-two-integers
0412-fizz-buzz
0509-fibonacci-number
0628-maximum-product-of-three-numbers
1979-find-greatest-common-divisor-of-array
3014-minimum-number-of-pushes-to-type-word-i
3345-smallest-divisible-digit-product-i
3536-maximum-product-of-two-digits
3550-smallest-index-with-digit-sum-equal-to-index
3622-check-divisibility-by-digit-sum-and-product
3658-gcd-of-odd-and-even-sums
3867-sum-of-gcd-of-formed-pairs
3870-count-commas-in-range
3871-count-commas-in-range-ii
3875-construct-uniform-parity-array-i

Array

0001-two-sum
0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0035-search-insert-position
0039-combination-sum
0040-combination-sum-ii
0042-trapping-rain-water
0046-permutations
0051-n-queens
0053-maximum-subarray
0054-spiral-matrix
0066-plus-one
0075-sort-colors
0078-subsets
0088-merge-sorted-array
0090-subsets-ii
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0136-single-number
0137-single-number-ii
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0209-minimum-size-subarray-sum
0216-combination-sum-iii
0217-contains-duplicate
0238-product-of-array-except-self
0260-single-number-iii
0268-missing-number
0283-move-zeroes
0287-find-the-duplicate-number
0334-increasing-triplet-subsequence
0347-top-k-frequent-elements
0525-contiguous-array
0560-subarray-sum-equals-k
0611-valid-triangle-number
0628-maximum-product-of-three-numbers
0724-find-pivot-index
0845-longest-mountain-in-array
0881-boats-to-save-people
0904-fruit-into-baskets
0977-squares-of-a-sorted-array
1464-maximum-product-of-two-elements-in-an-array
1480-running-sum-of-1d-array
1658-minimum-operations-to-reduce-x-to-zero
1929-concatenation-of-array
1979-find-greatest-common-divisor-of-array
2091-removing-minimum-and-maximum-from-array
2873-maximum-value-of-an-ordered-triplet-i
2958-length-of-longest-subarray-with-at-most-k-frequency
2996-smallest-missing-integer-greater-than-sequential-prefix-sum
3069-distribute-elements-into-two-arrays-i
3471-find-the-largest-almost-missing-integer
3550-smallest-index-with-digit-sum-equal-to-index
3731-find-missing-elements
3867-sum-of-gcd-of-formed-pairs
3875-construct-uniform-parity-array-i

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0013-roman-to-integer
0076-minimum-window-substring
0128-longest-consecutive-sequence
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0169-majority-element
0217-contains-duplicate
0268-missing-number
0347-top-k-frequent-elements
0424-longest-repeating-character-replacement
0525-contiguous-array
0560-subarray-sum-equals-k
0904-fruit-into-baskets
1658-minimum-operations-to-reduce-x-to-zero
2958-length-of-longest-subarray-with-at-most-k-frequency
2996-smallest-missing-integer-greater-than-sequential-prefix-sum
3016-minimum-number-of-pushes-to-type-word-ii
3090-maximum-length-substring-with-two-occurrences
3471-find-the-largest-almost-missing-integer
3731-find-missing-elements

Dynamic Programming

0022-generate-parentheses
0042-trapping-rain-water
0053-maximum-subarray
0121-best-time-to-buy-and-sell-stock
0338-counting-bits
0509-fibonacci-number
0845-longest-mountain-in-array

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0050-powx-n
0143-reorder-list
0203-remove-linked-list-elements
0206-reverse-linked-list
0231-power-of-two
0234-palindrome-linked-list
0509-fibonacci-number

Memoization

0509-fibonacci-number

Number Theory

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

Binary Search

0035-search-insert-position
0069-sqrtx
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0268-missing-number
0287-find-the-duplicate-number
0611-valid-triangle-number
1658-minimum-operations-to-reduce-x-to-zero

Two Pointers

0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0042-trapping-rain-water
0075-sort-colors
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0160-intersection-of-two-linked-lists
0167-two-sum-ii-input-array-is-sorted
0234-palindrome-linked-list
0283-move-zeroes
0287-find-the-duplicate-number
0344-reverse-string
0611-valid-triangle-number
0680-valid-palindrome-ii
0845-longest-mountain-in-array
0876-middle-of-the-linked-list
0881-boats-to-save-people
0977-squares-of-a-sorted-array
3867-sum-of-gcd-of-formed-pairs

Sorting

0015-3sum
0016-3sum-closest
0018-4sum
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0217-contains-duplicate
0268-missing-number
0347-top-k-frequent-elements
0611-valid-triangle-number
0628-maximum-product-of-three-numbers
0881-boats-to-save-people
0977-squares-of-a-sorted-array
1464-maximum-product-of-two-elements-in-an-array
2996-smallest-missing-integer-greater-than-sequential-prefix-sum
3016-minimum-number-of-pushes-to-type-word-ii
3517-smallest-palindromic-rearrangement-i
3536-maximum-product-of-two-digits
3731-find-missing-elements
3867-sum-of-gcd-of-formed-pairs

Simulation

0054-spiral-matrix
0412-fizz-buzz
1929-concatenation-of-array
3069-distribute-elements-into-two-arrays-i
3867-sum-of-gcd-of-formed-pairs

String

0003-longest-substring-without-repeating-characters
0013-roman-to-integer
0022-generate-parentheses
0076-minimum-window-substring
0125-valid-palindrome
0344-reverse-string
0412-fizz-buzz
0424-longest-repeating-character-replacement
0680-valid-palindrome-ii
1614-maximum-nesting-depth-of-the-parentheses
3014-minimum-number-of-pushes-to-type-word-i
3016-minimum-number-of-pushes-to-type-word-ii
3090-maximum-length-substring-with-two-occurrences
3517-smallest-palindromic-rearrangement-i

Greedy

0011-container-with-most-water
0334-increasing-triplet-subsequence
0611-valid-triangle-number
0680-valid-palindrome-ii
0881-boats-to-save-people
2091-removing-minimum-and-maximum-from-array
3014-minimum-number-of-pushes-to-type-word-i
3016-minimum-number-of-pushes-to-type-word-ii

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0525-contiguous-array
0560-subarray-sum-equals-k
0724-find-pivot-index
1480-running-sum-of-1d-array
1658-minimum-operations-to-reduce-x-to-zero
2873-maximum-value-of-an-ordered-triplet-i

Divide and Conquer

0053-maximum-subarray
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits
0347-top-k-frequent-elements

Counting

0169-majority-element
0347-top-k-frequent-elements
3016-minimum-number-of-pushes-to-type-word-ii

Heap (Priority Queue)

0347-top-k-frequent-elements
1464-maximum-product-of-two-elements-in-an-array

Counting Sort

3517-smallest-palindromic-rearrangement-i

Linked List

0002-add-two-numbers
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0083-remove-duplicates-from-sorted-list
0092-reverse-linked-list-ii
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0160-intersection-of-two-linked-lists
0203-remove-linked-list-elements
0206-reverse-linked-list
0234-palindrome-linked-list
0328-odd-even-linked-list
0430-flatten-a-multilevel-doubly-linked-list
0707-design-linked-list
0876-middle-of-the-linked-list
2058-find-the-minimum-and-maximum-number-of-nodes-between-critical-points

Union-Find

0128-longest-consecutive-sequence

Matrix

0054-spiral-matrix

Timsort

0881-boats-to-save-people

Stack

0042-trapping-rain-water
0143-reorder-list
0234-palindrome-linked-list
1614-maximum-nesting-depth-of-the-parentheses

Monotonic Stack

0042-trapping-rain-water

Bit Manipulation

0078-subsets
0090-subsets-ii
0136-single-number
0137-single-number-ii
0190-reverse-bits
0191-number-of-1-bits
0201-bitwise-and-of-numbers-range
0231-power-of-two
0260-single-number-iii
0268-missing-number
0287-find-the-duplicate-number
0338-counting-bits
0371-sum-of-two-integers

Pigeonhole Principle

0287-find-the-duplicate-number

Floyd's Cycle Finding Algorithm

0141-linked-list-cycle
0142-linked-list-cycle-ii
0287-find-the-duplicate-number

Longest Increasing Subsequence

0334-increasing-triplet-subsequence

Enumeration

0845-longest-mountain-in-array
3345-smallest-divisible-digit-product-i

Design

0707-design-linked-list

Depth-First Search

0430-flatten-a-multilevel-doubly-linked-list

Doubly-Linked List

0430-flatten-a-multilevel-doubly-linked-list

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0209-minimum-size-subarray-sum
0424-longest-repeating-character-replacement
0904-fruit-into-baskets
1658-minimum-operations-to-reduce-x-to-zero
2958-length-of-longest-subarray-with-at-most-k-frequency
3090-maximum-length-substring-with-two-occurrences

Bucket Sort

0347-top-k-frequent-elements

Quickselect

0347-top-k-frequent-elements

Backtracking

0022-generate-parentheses
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0051-n-queens
0077-combinations
0078-subsets
0090-subsets-ii
0216-combination-sum-iii

Bracket Sequences

0022-generate-parentheses
1614-maximum-nesting-depth-of-the-parentheses

Algorithm X

0051-n-queens