Leetcode

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

LeetCode Topics

Linked List

0002-add-two-numbers
0816-design-hashset
0817-design-hashmap
1411-convert-binary-number-in-a-linked-list-to-integer

Math

0002-add-two-numbers
0069-sqrtx
0189-rotate-array
0380-insert-delete-getrandom-o1
1411-convert-binary-number-in-a-linked-list-to-integer
2324-find-triangular-sum-of-an-array
3600-find-the-k-th-character-in-string-game-i

Recursion

0002-add-two-numbers
0394-decode-string
3600-find-the-k-th-character-in-string-game-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
0041-first-missing-positive
0049-group-anagrams
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0128-longest-consecutive-sequence
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0189-rotate-array
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0219-contains-duplicate-ii
0229-majority-element-ii
0238-product-of-array-except-self
0373-find-k-pairs-with-smallest-sums
0378-kth-smallest-element-in-a-sorted-matrix
0380-insert-delete-getrandom-o1
0455-assign-cookies
0560-subarray-sum-equals-k
0739-daily-temperatures
0816-design-hashset
0817-design-hashmap
0917-boats-to-save-people
0940-fruit-into-baskets
0948-sort-an-array
1463-the-k-weakest-rows-in-a-matrix
1478-maximum-number-of-events-that-can-be-attended
1510-find-lucky-integer-in-an-array
1603-running-sum-of-1d-array
2058-concatenation-of-array
2316-count-hills-and-valleys-in-an-array
2324-find-triangular-sum-of-an-array
2497-maximum-matching-of-players-with-trainers
3790-fruits-into-baskets-ii

Hash Table

0001-two-sum
0041-first-missing-positive
0049-group-anagrams
0128-longest-consecutive-sequence
0169-majority-element
0217-contains-duplicate
0219-contains-duplicate-ii
0229-majority-element-ii
0242-valid-anagram
0380-insert-delete-getrandom-o1
0560-subarray-sum-equals-k
0816-design-hashset
0817-design-hashmap
0940-fruit-into-baskets
1510-find-lucky-integer-in-an-array

Sorting

0015-3sum
0016-3sum-closest
0018-4sum
0049-group-anagrams
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0378-kth-smallest-element-in-a-sorted-matrix
0455-assign-cookies
0917-boats-to-save-people
0948-sort-an-array
1463-the-k-weakest-rows-in-a-matrix
1478-maximum-number-of-events-that-can-be-attended
2497-maximum-matching-of-players-with-trainers

String

0014-longest-common-prefix
0020-valid-parentheses
0049-group-anagrams
0125-valid-palindrome
0151-reverse-words-in-a-string
0242-valid-anagram
0257-binary-tree-paths
0392-is-subsequence
0394-decode-string
0680-valid-palindrome-ii
0857-positions-of-large-groups
0874-backspace-string-compare
1302-delete-characters-to-make-fancy-string
1894-merge-strings-alternately
1967-longest-substring-of-all-vowels-in-order
2260-divide-a-string-into-groups-of-size-k
3396-valid-word
3684-substring-matching-pattern

Sliding Window

0219-contains-duplicate-ii
0940-fruit-into-baskets
1967-longest-substring-of-all-vowels-in-order

Binary Search

0069-sqrtx
0167-two-sum-ii-input-array-is-sorted
0222-count-complete-tree-nodes
0378-kth-smallest-element-in-a-sorted-matrix
1463-the-k-weakest-rows-in-a-matrix
3790-fruits-into-baskets-ii

Simulation

0874-backspace-string-compare
2058-concatenation-of-array
2260-divide-a-string-into-groups-of-size-k
2324-find-triangular-sum-of-an-array
3600-find-the-k-th-character-in-string-game-i
3790-fruits-into-baskets-ii

Backtracking

0257-binary-tree-paths

Tree

0102-binary-tree-level-order-traversal
0222-count-complete-tree-nodes
0257-binary-tree-paths
2416-evaluate-boolean-binary-tree

Depth-First Search

0257-binary-tree-paths
2416-evaluate-boolean-binary-tree

Binary Tree

0102-binary-tree-level-order-traversal
0222-count-complete-tree-nodes
0257-binary-tree-paths
2416-evaluate-boolean-binary-tree

Design

0380-insert-delete-getrandom-o1
0816-design-hashset
0817-design-hashmap

Hash Function

0816-design-hashset
0817-design-hashmap

Divide and Conquer

0169-majority-element
0215-kth-largest-element-in-an-array
0948-sort-an-array

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0373-find-k-pairs-with-smallest-sums
0378-kth-smallest-element-in-a-sorted-matrix
0948-sort-an-array
1463-the-k-weakest-rows-in-a-matrix
1478-maximum-number-of-events-that-can-be-attended

Quickselect

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

Merge Sort

0948-sort-an-array

Bucket Sort

0948-sort-an-array

Radix Sort

0948-sort-an-array

Counting Sort

0169-majority-element
0229-majority-element-ii
0948-sort-an-array
1510-find-lucky-integer-in-an-array

Two Pointers

0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0125-valid-palindrome
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0392-is-subsequence
0455-assign-cookies
0680-valid-palindrome-ii
0874-backspace-string-compare
0917-boats-to-save-people
1894-merge-strings-alternately
2497-maximum-matching-of-players-with-trainers

Trie

0014-longest-common-prefix

Breadth-First Search

0102-binary-tree-level-order-traversal

Union Find

0128-longest-consecutive-sequence

Bit Manipulation

0222-count-complete-tree-nodes
3600-find-the-k-th-character-in-string-game-i

Dynamic Programming

0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0392-is-subsequence

Greedy

0011-container-with-most-water
0122-best-time-to-buy-and-sell-stock-ii
0455-assign-cookies
0680-valid-palindrome-ii
0917-boats-to-save-people
1478-maximum-number-of-events-that-can-be-attended
2497-maximum-matching-of-players-with-trainers

Prefix Sum

0238-product-of-array-except-self
0560-subarray-sum-equals-k
1603-running-sum-of-1d-array

Stack

0020-valid-parentheses
0394-decode-string
0739-daily-temperatures
0874-backspace-string-compare

Matrix

0378-kth-smallest-element-in-a-sorted-matrix
1463-the-k-weakest-rows-in-a-matrix

Randomized

0380-insert-delete-getrandom-o1

String Matching

3684-substring-matching-pattern

Combinatorics

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

Monotonic Stack

0739-daily-temperatures

Segment Tree

3790-fruits-into-baskets-ii

Ordered Set

3790-fruits-into-baskets-ii