Data-Structure-and-Algorithm

LeetCode Topics

Two Pointers

0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0042-trapping-rain-water
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0125-valid-palindrome
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0283-move-zeroes
0344-reverse-string
0345-reverse-vowels-of-a-string
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0392-is-subsequence
0443-string-compression
0532-k-diff-pairs-in-an-array
0567-permutation-in-string
0658-find-k-closest-elements
0680-valid-palindrome-ii
0763-partition-labels
0821-shortest-distance-to-a-character
0844-backspace-string-compare
0881-boats-to-save-people
0905-sort-array-by-parity
0977-squares-of-a-sorted-array
0986-interval-list-intersections
1332-remove-palindromic-subsequences
1679-max-number-of-k-sum-pairs
2460-apply-operations-to-an-array

String

0003-longest-substring-without-repeating-characters
0014-longest-common-prefix
0020-valid-parentheses
0022-generate-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0065-valid-number
0076-minimum-window-substring
0125-valid-palindrome
0242-valid-anagram
0344-reverse-string
0345-reverse-vowels-of-a-string
0389-find-the-difference
0392-is-subsequence
0395-longest-substring-with-at-least-k-repeating-characters
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0443-string-compression
0567-permutation-in-string
0680-valid-palindrome-ii
0763-partition-labels
0821-shortest-distance-to-a-character
0844-backspace-string-compare
1143-longest-common-subsequence
1332-remove-palindromic-subsequences
1371-find-the-longest-substring-containing-vowels-in-even-counts
1910-remove-all-occurrences-of-a-substring

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
0014-longest-common-prefix
0015-3sum
0016-3sum-closest
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0042-trapping-rain-water
0046-permutations
0051-n-queens
0053-maximum-subarray
0054-spiral-matrix
0074-search-a-2d-matrix
0075-sort-colors
0078-subsets
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0136-single-number
0137-single-number-ii
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0189-rotate-array
0204-count-primes
0209-minimum-size-subarray-sum
0217-contains-duplicate
0219-contains-duplicate-ii
0220-contains-duplicate-iii
0238-product-of-array-except-self
0239-sliding-window-maximum
0268-missing-number
0283-move-zeroes
0303-range-sum-query-immutable
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0414-third-maximum-number
0448-find-all-numbers-disappeared-in-an-array
0523-continuous-subarray-sum
0525-contiguous-array
0532-k-diff-pairs-in-an-array
0560-subarray-sum-equals-k
0643-maximum-average-subarray-i
0658-find-k-closest-elements
0704-binary-search
0713-subarray-product-less-than-k
0724-find-pivot-index
0821-shortest-distance-to-a-character
0852-peak-index-in-a-mountain-array
0881-boats-to-save-people
0905-sort-array-by-parity
0912-sort-an-array
0930-binary-subarrays-with-sum
0941-valid-mountain-array
0974-subarray-sums-divisible-by-k
0977-squares-of-a-sorted-array
0986-interval-list-intersections
1004-max-consecutive-ones-iii
1200-minimum-absolute-difference
1248-count-number-of-nice-subarrays
1480-running-sum-of-1d-array
1493-longest-subarray-of-1s-after-deleting-one-element
1524-number-of-sub-arrays-with-odd-sum
1546-maximum-number-of-non-overlapping-subarrays-with-sum-equals-target
1679-max-number-of-k-sum-pairs
1732-find-the-highest-altitude
1752-check-if-array-is-sorted-and-rotated
1991-find-the-middle-index-in-array
2352-equal-row-and-column-pairs
2460-apply-operations-to-an-array
2461-maximum-sum-of-distinct-subarrays-with-length-k
2951-find-the-peaks
2965-find-missing-and-repeated-values

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0169-majority-element
0217-contains-duplicate
0219-contains-duplicate-ii
0242-valid-anagram
0268-missing-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0389-find-the-difference
0395-longest-substring-with-at-least-k-repeating-characters
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0448-find-all-numbers-disappeared-in-an-array
0523-continuous-subarray-sum
0525-contiguous-array
0532-k-diff-pairs-in-an-array
0560-subarray-sum-equals-k
0567-permutation-in-string
0763-partition-labels
0930-binary-subarrays-with-sum
0974-subarray-sums-divisible-by-k
1248-count-number-of-nice-subarrays
1371-find-the-longest-substring-containing-vowels-in-even-counts
1546-maximum-number-of-non-overlapping-subarrays-with-sum-equals-target
1679-max-number-of-k-sum-pairs
2352-equal-row-and-column-pairs
2461-maximum-sum-of-distinct-subarrays-with-length-k
2965-find-missing-and-repeated-values

Math

0007-reverse-integer
0009-palindrome-number
0050-powx-n
0069-sqrtx
0070-climbing-stairs
0189-rotate-array
0204-count-primes
0231-power-of-two
0258-add-digits
0268-missing-number
0509-fibonacci-number
0523-continuous-subarray-sum
1248-count-number-of-nice-subarrays
1524-number-of-sub-arrays-with-odd-sum
2965-find-missing-and-repeated-values

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0069-sqrtx
0074-search-a-2d-matrix
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0268-missing-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0532-k-diff-pairs-in-an-array
0658-find-k-closest-elements
0704-binary-search
0713-subarray-product-less-than-k
0852-peak-index-in-a-mountain-array
1004-max-consecutive-ones-iii

Bit Manipulation

0078-subsets
0136-single-number
0137-single-number-ii
0191-number-of-1-bits
0231-power-of-two
0268-missing-number
0338-counting-bits
0389-find-the-difference
1318-minimum-flips-to-make-a-or-b-equal-to-c
1371-find-the-longest-substring-containing-vowels-in-even-counts

Sorting

0015-3sum
0016-3sum-closest
0018-4sum
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0217-contains-duplicate
0220-contains-duplicate-iii
0242-valid-anagram
0268-missing-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0389-find-the-difference
0414-third-maximum-number
0532-k-diff-pairs-in-an-array
0658-find-k-closest-elements
0881-boats-to-save-people
0905-sort-array-by-parity
0912-sort-an-array
0977-squares-of-a-sorted-array
1200-minimum-absolute-difference
1679-max-number-of-k-sum-pairs

Divide and Conquer

0004-median-of-two-sorted-arrays
0053-maximum-subarray
0169-majority-element
0191-number-of-1-bits
0395-longest-substring-with-at-least-k-repeating-characters
0912-sort-an-array

Heap (Priority Queue)

0239-sliding-window-maximum
0658-find-k-closest-elements
0912-sort-an-array

Merge Sort

0912-sort-an-array

Bucket Sort

0220-contains-duplicate-iii
0912-sort-an-array

Radix Sort

0912-sort-an-array

Counting Sort

0169-majority-element
0912-sort-an-array

Sweep Line

0986-interval-list-intersections

Linked List

0024-swap-nodes-in-pairs
0206-reverse-linked-list

Recursion

0024-swap-nodes-in-pairs
0050-powx-n
0206-reverse-linked-list
0231-power-of-two
0509-fibonacci-number

Trie

0014-longest-common-prefix

Stack

0020-valid-parentheses
0042-trapping-rain-water
0844-backspace-string-compare
1910-remove-all-occurrences-of-a-substring

Dynamic Programming

0022-generate-parentheses
0042-trapping-rain-water
0053-maximum-subarray
0070-climbing-stairs
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0338-counting-bits
0392-is-subsequence
0509-fibonacci-number
1143-longest-common-subsequence
1493-longest-subarray-of-1s-after-deleting-one-element
1524-number-of-sub-arrays-with-odd-sum

Monotonic Stack

0042-trapping-rain-water

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0220-contains-duplicate-iii
0239-sliding-window-maximum
0395-longest-substring-with-at-least-k-repeating-characters
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0567-permutation-in-string
0643-maximum-average-subarray-i
0658-find-k-closest-elements
0713-subarray-product-less-than-k
0930-binary-subarrays-with-sum
1004-max-consecutive-ones-iii
1248-count-number-of-nice-subarrays
1493-longest-subarray-of-1s-after-deleting-one-element
2461-maximum-sum-of-distinct-subarrays-with-length-k

Queue

0239-sliding-window-maximum

Monotonic Queue

0239-sliding-window-maximum

Memoization

0070-climbing-stairs
0509-fibonacci-number

Database

0175-combine-two-tables
0176-second-highest-salary
0181-employees-earning-more-than-their-managers
0182-duplicate-emails
0183-customers-who-never-order
0196-delete-duplicate-emails
0197-rising-temperature
0511-game-play-analysis-i
0570-managers-with-at-least-5-direct-reports

Simulation

0054-spiral-matrix
0258-add-digits
0844-backspace-string-compare
1910-remove-all-occurrences-of-a-substring
2352-equal-row-and-column-pairs
2460-apply-operations-to-an-array

Number Theory

0204-count-primes
0258-add-digits

Design

0303-range-sum-query-immutable

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0303-range-sum-query-immutable
0523-continuous-subarray-sum
0525-contiguous-array
0560-subarray-sum-equals-k
0713-subarray-product-less-than-k
0724-find-pivot-index
0930-binary-subarrays-with-sum
0974-subarray-sums-divisible-by-k
1004-max-consecutive-ones-iii
1248-count-number-of-nice-subarrays
1371-find-the-longest-substring-containing-vowels-in-even-counts
1480-running-sum-of-1d-array
1524-number-of-sub-arrays-with-odd-sum
1546-maximum-number-of-non-overlapping-subarrays-with-sum-equals-target
1732-find-the-highest-altitude
1991-find-the-middle-index-in-array

Greedy

0011-container-with-most-water
0122-best-time-to-buy-and-sell-stock-ii
0680-valid-palindrome-ii
0763-partition-labels
0881-boats-to-save-people
1546-maximum-number-of-non-overlapping-subarrays-with-sum-equals-target

Enumeration

0204-count-primes
2951-find-the-peaks

Backtracking

0022-generate-parentheses
0046-permutations
0051-n-queens
0078-subsets

Matrix

0054-spiral-matrix
0074-search-a-2d-matrix
2352-equal-row-and-column-pairs
2965-find-missing-and-repeated-values

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string

Algorithm X

0051-n-queens

Ordered Set

0220-contains-duplicate-iii