LeetCode

LeetCode Topics

Array

0001-two-sum
0011-container-with-most-water
0027-remove-element
0034-find-first-and-last-position-of-element-in-sorted-array
0039-combination-sum
0049-group-anagrams
0075-sort-colors
0088-merge-sorted-array
0121-best-time-to-buy-and-sell-stock
0130-surrounded-regions
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0200-number-of-islands
0209-minimum-size-subarray-sum
0217-contains-duplicate
0219-contains-duplicate-ii
0283-move-zeroes
0287-find-the-duplicate-number
0346-moving-average-from-data-stream
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0410-split-array-largest-sum
0485-max-consecutive-ones
0643-maximum-average-subarray-i
0695-max-area-of-island
0733-flood-fill
0744-find-smallest-letter-greater-than-target
0860-design-circular-queue
1046-max-consecutive-ones-iii
1146-snapshot-array
1171-shortest-path-in-binary-matrix
1470-shuffle-the-array
1929-concatenation-of-array

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0013-roman-to-integer
0049-group-anagrams
0141-linked-list-cycle
0169-majority-element
0202-happy-number
0205-isomorphic-strings
0217-contains-duplicate
0219-contains-duplicate-ii
0242-valid-anagram
0290-word-pattern
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0383-ransom-note
1146-snapshot-array

Divide and Conquer

0169-majority-element
0347-top-k-frequent-elements

Sorting

0049-group-anagrams
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0217-contains-duplicate
0242-valid-anagram
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii

Heap (Priority Queue)

0347-top-k-frequent-elements

Bucket Sort

0347-top-k-frequent-elements

Counting

0169-majority-element
0347-top-k-frequent-elements
0383-ransom-note

Quickselect

0347-top-k-frequent-elements

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0008-string-to-integer-atoi
0013-roman-to-integer
0020-valid-parentheses
0049-group-anagrams
0125-valid-palindrome
0151-reverse-words-in-a-string
0205-isomorphic-strings
0242-valid-anagram
0290-word-pattern
0344-reverse-string
0383-ransom-note

Stack

0020-valid-parentheses
0143-reorder-list

Math

0013-roman-to-integer
0202-happy-number
0509-fibonacci-number

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0019-remove-nth-node-from-end-of-list
0027-remove-element
0075-sort-colors
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0143-reorder-list
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0202-happy-number
0283-move-zeroes
0287-find-the-duplicate-number
0344-reverse-string
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii

Sliding Window

0003-longest-substring-without-repeating-characters
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0643-maximum-average-subarray-i
1046-max-consecutive-ones-iii

Binary Search

0034-find-first-and-last-position-of-element-in-sorted-array
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0287-find-the-duplicate-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0410-split-array-largest-sum
0744-find-smallest-letter-greater-than-target
1046-max-consecutive-ones-iii
1146-snapshot-array

Prefix Sum

0209-minimum-size-subarray-sum
0410-split-array-largest-sum
1046-max-consecutive-ones-iii

Bit Manipulation

0287-find-the-duplicate-number

Dynamic Programming

0005-longest-palindromic-substring
0121-best-time-to-buy-and-sell-stock
0410-split-array-largest-sum
0509-fibonacci-number

Greedy

0011-container-with-most-water
0410-split-array-largest-sum

Depth-First Search

0130-surrounded-regions
0200-number-of-islands
0547-number-of-provinces
0695-max-area-of-island
0733-flood-fill

Breadth-First Search

0130-surrounded-regions
0200-number-of-islands
0547-number-of-provinces
0695-max-area-of-island
0733-flood-fill
1171-shortest-path-in-binary-matrix

Union Find

0130-surrounded-regions
0200-number-of-islands
0547-number-of-provinces
0695-max-area-of-island

Graph

0547-number-of-provinces

Matrix

0130-surrounded-regions
0200-number-of-islands
0695-max-area-of-island
0733-flood-fill
1171-shortest-path-in-binary-matrix

Linked List

0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0141-linked-list-cycle
0143-reorder-list
0860-design-circular-queue

Design

0346-moving-average-from-data-stream
0860-design-circular-queue
1146-snapshot-array

Queue

0346-moving-average-from-data-stream
0860-design-circular-queue

Data Stream

0346-moving-average-from-data-stream

Simulation

1929-concatenation-of-array

Recursion

0021-merge-two-sorted-lists
0143-reorder-list
0509-fibonacci-number

Memoization

0509-fibonacci-number

Backtracking

0039-combination-sum