Leetcode-Solutions

LeetCode Topics

Array

0001-two-sum
0026-remove-duplicates-from-sorted-array
0036-valid-sudoku
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0041-first-missing-positive
0046-permutations
0051-n-queens
0055-jump-game
0075-sort-colors
0079-word-search
0090-subsets-ii
0169-majority-element
0189-rotate-array
0215-kth-largest-element-in-an-array
0216-combination-sum-iii
0238-product-of-array-except-self
0287-find-the-duplicate-number
0334-increasing-triplet-subsequence
0373-find-k-pairs-with-smallest-sums
0455-assign-cookies
0860-lemonade-change
0930-binary-subarrays-with-sum
0992-subarrays-with-k-different-integers
1248-count-number-of-nice-subarrays
1288-remove-covered-intervals
1354-construct-target-array-with-multiple-sums
1423-maximum-points-you-can-obtain-from-cards
1493-longest-subarray-of-1s-after-deleting-one-element
1679-max-number-of-k-sum-pairs
1752-check-if-array-is-sorted-and-rotated
1838-frequency-of-the-most-frequent-element
1846-maximum-element-after-decreasing-and-rearranging
1967-number-of-strings-that-appear-as-substrings-in-word
2144-minimum-cost-of-buying-candies-with-discount
3020-find-the-maximum-number-of-elements-in-subset
3737-count-subarrays-with-majority-element-i

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0930-binary-subarrays-with-sum
0992-subarrays-with-k-different-integers
1248-count-number-of-nice-subarrays
1358-number-of-substrings-containing-all-three-characters
1423-maximum-points-you-can-obtain-from-cards
1493-longest-subarray-of-1s-after-deleting-one-element
1838-frequency-of-the-most-frequent-element

Prefix Sum

0238-product-of-array-except-self
0930-binary-subarrays-with-sum
1248-count-number-of-nice-subarrays
1423-maximum-points-you-can-obtain-from-cards
1838-frequency-of-the-most-frequent-element
3737-count-subarrays-with-majority-element-i

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0017-letter-combinations-of-a-phone-number
0036-valid-sudoku
0037-sudoku-solver
0041-first-missing-positive
0076-minimum-window-substring
0169-majority-element
0264-ugly-number-ii
0930-binary-subarrays-with-sum
0992-subarrays-with-k-different-integers
1248-count-number-of-nice-subarrays
1358-number-of-substrings-containing-all-three-characters
1679-max-number-of-k-sum-pairs
3020-find-the-maximum-number-of-elements-in-subset
3737-count-subarrays-with-majority-element-i

Math

0007-reverse-integer
0009-palindrome-number
0189-rotate-array
0264-ugly-number-ii
0371-sum-of-two-integers
0509-fibonacci-number
1248-count-number-of-nice-subarrays
3754-concatenate-non-zero-digits-and-multiply-by-sum-i

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0076-minimum-window-substring
0079-word-search
0125-valid-palindrome
0482-license-key-formatting
0678-valid-parenthesis-string
1358-number-of-substrings-containing-all-three-characters
1967-number-of-strings-that-appear-as-substrings-in-word
2390-removing-stars-from-a-string

Counting

0169-majority-element
0992-subarrays-with-k-different-integers
3737-count-subarrays-with-majority-element-i

Greedy

0055-jump-game
0334-increasing-triplet-subsequence
0455-assign-cookies
0678-valid-parenthesis-string
0860-lemonade-change
1838-frequency-of-the-most-frequent-element
1846-maximum-element-after-decreasing-and-rearranging
2144-minimum-cost-of-buying-candies-with-discount

Sorting

0075-sort-colors
0169-majority-element
0215-kth-largest-element-in-an-array
0455-assign-cookies
1288-remove-covered-intervals
1679-max-number-of-k-sum-pairs
1838-frequency-of-the-most-frequent-element
1846-maximum-element-after-decreasing-and-rearranging
2144-minimum-cost-of-buying-candies-with-discount

Two Pointers

0005-longest-palindromic-substring
0026-remove-duplicates-from-sorted-array
0075-sort-colors
0125-valid-palindrome
0189-rotate-array
0287-find-the-duplicate-number
0455-assign-cookies
1679-max-number-of-k-sum-pairs

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0055-jump-game
0264-ugly-number-ii
0338-counting-bits
0509-fibonacci-number
0678-valid-parenthesis-string
1493-longest-subarray-of-1s-after-deleting-one-element

Recursion

0509-fibonacci-number

Memoization

0509-fibonacci-number

Binary Search

0287-find-the-duplicate-number
1838-frequency-of-the-most-frequent-element

Divide and Conquer

0169-majority-element
0215-kth-largest-element-in-an-array
3737-count-subarrays-with-majority-element-i

Segment Tree

3737-count-subarrays-with-majority-element-i

Merge Sort

3737-count-subarrays-with-majority-element-i

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0051-n-queens
0079-word-search
0090-subsets-ii
0216-combination-sum-iii

Database

0596-classes-with-at-least-5-students
1141-user-activity-for-the-past-30-days-i
1193-monthly-transactions-i

Bit Manipulation

0090-subsets-ii
0287-find-the-duplicate-number
0338-counting-bits
0371-sum-of-two-integers

Enumeration

3020-find-the-maximum-number-of-elements-in-subset

Matrix

0036-valid-sudoku
0037-sudoku-solver
0079-word-search

Depth-First Search

0079-word-search

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0264-ugly-number-ii
0373-find-k-pairs-with-smallest-sums
1354-construct-target-array-with-multiple-sums

Quickselect

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

Stack

0678-valid-parenthesis-string
2390-removing-stars-from-a-string

Simulation

2390-removing-stars-from-a-string