leetcode

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

LeetCode Topics

Array

0001-two-sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0036-valid-sudoku
0049-group-anagrams
0088-merge-sorted-array
0209-minimum-size-subarray-sum
0217-contains-duplicate
0239-sliding-window-maximum
0268-missing-number
0346-moving-average-from-data-stream
0347-top-k-frequent-elements
0496-next-greater-element-i
0525-contiguous-array
0643-maximum-average-subarray-i
0695-max-area-of-island
0739-daily-temperatures
1019-squares-of-a-sorted-array
1046-max-consecutive-ones-iii
1098-largest-unique-number
1354-find-players-with-zero-or-one-losses
1391-counting-elements
1514-minimum-value-to-get-positive-step-by-step-sum
1603-running-sum-of-1d-array
1833-find-the-highest-altitude
2038-nearest-exit-from-entrance-in-maze
2211-k-radius-subarray-averages
2331-intersection-of-multiple-arrays
2338-minimum-consecutive-cards-to-pick-up
2445-reachable-nodes-with-restrictions
2469-longest-subsequence-with-limited-sum

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0036-valid-sudoku
0049-group-anagrams
0141-linked-list-cycle
0217-contains-duplicate
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
0383-ransom-note
0496-next-greater-element-i
0525-contiguous-array
0782-jewels-and-stones
1098-largest-unique-number
1297-maximum-number-of-balloons
1354-find-players-with-zero-or-one-losses
1391-counting-elements
1960-check-if-the-sentence-is-pangram
2053-check-if-all-characters-have-equal-number-of-occurrences
2331-intersection-of-multiple-arrays
2338-minimum-consecutive-cards-to-pick-up
2427-first-letter-to-appear-twice
2445-reachable-nodes-with-restrictions

String

0003-longest-substring-without-repeating-characters
0020-valid-parentheses
0049-group-anagrams
0071-simplify-path
0242-valid-anagram
0344-reverse-string
0383-ransom-note
0557-reverse-words-in-a-string-iii
0782-jewels-and-stones
0874-backspace-string-compare
1128-remove-all-adjacent-duplicates-in-string
1297-maximum-number-of-balloons
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1567-maximum-number-of-vowels-in-a-substring-of-given-length
1666-make-the-string-great
1960-check-if-the-sentence-is-pangram
2053-check-if-all-characters-have-equal-number-of-occurrences
2427-first-letter-to-appear-twice
2470-removing-stars-from-a-string

Sorting

0049-group-anagrams
0088-merge-sorted-array
0217-contains-duplicate
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
1019-squares-of-a-sorted-array
1098-largest-unique-number
1354-find-players-with-zero-or-one-losses
2331-intersection-of-multiple-arrays
2469-longest-subsequence-with-limited-sum

Bit Manipulation

0268-missing-number
2427-first-letter-to-appear-twice

Counting

0347-top-k-frequent-elements
0383-ransom-note
1297-maximum-number-of-balloons
1354-find-players-with-zero-or-one-losses
2053-check-if-all-characters-have-equal-number-of-occurrences
2331-intersection-of-multiple-arrays
2427-first-letter-to-appear-twice

Divide and Conquer

0347-top-k-frequent-elements

Heap (Priority Queue)

0239-sliding-window-maximum
0347-top-k-frequent-elements

Bucket Sort

0347-top-k-frequent-elements

Quickselect

0347-top-k-frequent-elements

Two Pointers

0026-remove-duplicates-from-sorted-array
0027-remove-element
0088-merge-sorted-array
0141-linked-list-cycle
0234-palindrome-linked-list
0344-reverse-string
0557-reverse-words-in-a-string-iii
0874-backspace-string-compare
0908-middle-of-the-linked-list
1019-squares-of-a-sorted-array
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence

Binary Search

0209-minimum-size-subarray-sum
0268-missing-number
1046-max-consecutive-ones-iii
2469-longest-subsequence-with-limited-sum

Sliding Window

0003-longest-substring-without-repeating-characters
0209-minimum-size-subarray-sum
0239-sliding-window-maximum
0643-maximum-average-subarray-i
1046-max-consecutive-ones-iii
1567-maximum-number-of-vowels-in-a-substring-of-given-length
2211-k-radius-subarray-averages
2338-minimum-consecutive-cards-to-pick-up

Prefix Sum

0209-minimum-size-subarray-sum
0525-contiguous-array
1046-max-consecutive-ones-iii
1514-minimum-value-to-get-positive-step-by-step-sum
1603-running-sum-of-1d-array
1833-find-the-highest-altitude
2469-longest-subsequence-with-limited-sum

Matrix

0036-valid-sudoku
0695-max-area-of-island
2038-nearest-exit-from-entrance-in-maze

Math

0268-missing-number

String Matching

1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence

Linked List

0083-remove-duplicates-from-sorted-list
0092-reverse-linked-list-ii
0141-linked-list-cycle
0234-palindrome-linked-list
0908-middle-of-the-linked-list

Stack

0020-valid-parentheses
0071-simplify-path
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0496-next-greater-element-i
0739-daily-temperatures
0874-backspace-string-compare
0937-online-stock-span
1128-remove-all-adjacent-duplicates-in-string
1666-make-the-string-great
2470-removing-stars-from-a-string

Recursion

0234-palindrome-linked-list

Simulation

0874-backspace-string-compare
2470-removing-stars-from-a-string

Design

0232-implement-queue-using-stacks
0346-moving-average-from-data-stream
0937-online-stock-span

Queue

0232-implement-queue-using-stacks
0239-sliding-window-maximum
0346-moving-average-from-data-stream

Data Stream

0346-moving-average-from-data-stream
0937-online-stock-span

Monotonic Stack

0496-next-greater-element-i
0739-daily-temperatures
0937-online-stock-span

Monotonic Queue

0239-sliding-window-maximum

Tree

0100-same-tree
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0199-binary-tree-right-side-view
0515-find-largest-value-in-each-tree-row
0543-diameter-of-binary-tree
0975-range-sum-of-bst
1092-maximum-difference-between-node-and-ancestor
1544-count-good-nodes-in-binary-tree
2445-reachable-nodes-with-restrictions

Depth-First Search

0100-same-tree
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0199-binary-tree-right-side-view
0323-number-of-connected-components-in-an-undirected-graph
0515-find-largest-value-in-each-tree-row
0543-diameter-of-binary-tree
0695-max-area-of-island
0975-range-sum-of-bst
1092-maximum-difference-between-node-and-ancestor
1544-count-good-nodes-in-binary-tree
2121-find-if-path-exists-in-graph
2445-reachable-nodes-with-restrictions

Breadth-First Search

0100-same-tree
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0199-binary-tree-right-side-view
0323-number-of-connected-components-in-an-undirected-graph
0515-find-largest-value-in-each-tree-row
0695-max-area-of-island
1544-count-good-nodes-in-binary-tree
2038-nearest-exit-from-entrance-in-maze
2121-find-if-path-exists-in-graph
2445-reachable-nodes-with-restrictions

Binary Tree

0100-same-tree
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0199-binary-tree-right-side-view
0515-find-largest-value-in-each-tree-row
0543-diameter-of-binary-tree
0975-range-sum-of-bst
1092-maximum-difference-between-node-and-ancestor
1544-count-good-nodes-in-binary-tree

Binary Search Tree

0975-range-sum-of-bst

Union Find

0323-number-of-connected-components-in-an-undirected-graph
0695-max-area-of-island
2121-find-if-path-exists-in-graph
2445-reachable-nodes-with-restrictions

Graph

0323-number-of-connected-components-in-an-undirected-graph
2121-find-if-path-exists-in-graph
2445-reachable-nodes-with-restrictions

Greedy

2469-longest-subsequence-with-limited-sum