leetcode-practice

Collection of LeetCode questions to ace the coding interview! - Created using LeetHub

LeetCode Topics

Math

Problem Name	Difficulty
0002-add-two-numbers
0009-palindrome-number
0013-roman-to-integer
0066-plus-one
0202-happy-number
0241-different-ways-to-add-parentheses
0263-ugly-number
0268-missing-number
0326-power-of-three
0367-valid-perfect-square	Easy
0539-minimum-time-difference
1406-subtract-the-product-and-sum-of-digits-of-an-integer
1635-number-of-good-pairs
2556-convert-the-temperature
2946-matrix-similarity-after-cyclic-shifts	Easy
3227-find-missing-and-repeated-values
3512-minimum-operations-to-make-array-sum-divisible-by-k	Easy
3515-find-if-digit-game-can-be-won
3555-final-array-state-after-k-multiplication-operations-i

Database

Problem Name	Difficulty
0175-combine-two-tables
0181-employees-earning-more-than-their-managers
0182-duplicate-emails
0183-customers-who-never-order
0196-delete-duplicate-emails
0577-employee-bonus
0584-find-customer-referee
0595-big-countries
0619-biggest-single-number
0620-not-boring-movies
0627-swap-salary
1877-find-followers-count
1908-recyclable-and-low-fat-products

Array

Problem Name	Difficulty
0001-two-sum
0014-longest-common-prefix	Easy
0035-search-insert-position
0066-plus-one
0118-pascals-triangle	Easy
0136-single-number	Easy
0217-contains-duplicate
0219-contains-duplicate-ii
0228-summary-ranges
0268-missing-number
0283-move-zeroes
0347-top-k-frequent-elements
0500-keyboard-row
0539-minimum-time-difference
0636-exclusive-time-of-functions	Medium
0861-flipping-an-image
1241-decompress-run-length-encoded-list
1435-xor-queries-of-a-subarray
1475-final-prices-with-a-special-discount-in-a-shop	Easy
1528-kids-with-the-greatest-number-of-candies
1635-number-of-good-pairs
1730-special-array-with-x-elements-greater-than-or-equal-x
1755-defuse-the-bomb
1786-count-the-number-of-consistent-strings
1878-check-if-array-is-sorted-and-rotated
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1927-maximum-ascending-subarray-sum
2006-find-the-student-that-will-replace-the-chalk
2048-build-array-from-permutation
2116-count-number-of-pairs-with-absolute-difference-k
2132-convert-1d-array-into-2d-array
2137-final-value-of-variable-after-performing-operations
2148-minimum-number-of-moves-to-seat-everyone
2159-two-out-of-three
2292-counting-words-with-a-given-prefix
2308-divide-array-into-equal-pairs
2502-sort-the-people
2551-apply-operations-to-an-array
2552-maximum-sum-of-distinct-subarrays-with-length-k
2639-separate-the-digits-in-an-array
2876-number-of-employees-who-met-the-target
2946-matrix-similarity-after-cyclic-shifts	Easy
3227-find-missing-and-repeated-values
3251-maximum-area-of-longest-diagonal-rectangle
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3429-special-array-i
3471-minimum-average-of-smallest-and-largest-elements
3488-closest-equal-element-queries	Medium
3512-minimum-operations-to-make-array-sum-divisible-by-k	Easy
3515-find-if-digit-game-can-be-won
3555-final-array-state-after-k-multiplication-operations-i
3656-minimum-number-of-operations-to-make-elements-in-array-distinct

Matrix

Problem Name	Difficulty
0861-flipping-an-image
2132-convert-1d-array-into-2d-array
2946-matrix-similarity-after-cyclic-shifts	Easy
3227-find-missing-and-repeated-values

Simulation

Problem Name	Difficulty
0844-backspace-string-compare	Easy
0861-flipping-an-image
1708-design-parking-system
2006-find-the-student-that-will-replace-the-chalk
2048-build-array-from-permutation
2076-sum-of-digits-of-string-after-convert
2132-convert-1d-array-into-2d-array
2137-final-value-of-variable-after-performing-operations
2551-apply-operations-to-an-array
2639-separate-the-digits-in-an-array
2800-minimum-string-length-after-removing-substrings
2886-faulty-keyboard
2946-matrix-similarity-after-cyclic-shifts	Easy
3447-clear-digits
3555-final-array-state-after-k-multiplication-operations-i

Binary Search

Problem Name	Difficulty
0035-search-insert-position
0268-missing-number
0367-valid-perfect-square	Easy
0374-guess-number-higher-or-lower
1730-special-array-with-x-elements-greater-than-or-equal-x
2006-find-the-student-that-will-replace-the-chalk
3488-closest-equal-element-queries	Medium

Prefix Sum

Problem Name	Difficulty
1435-xor-queries-of-a-subarray
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
2006-find-the-student-that-will-replace-the-chalk

String

Problem Name	Difficulty
0003-longest-substring-without-repeating-characters
0013-roman-to-integer
0014-longest-common-prefix
0020-valid-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0058-length-of-last-word
0125-valid-palindrome
0241-different-ways-to-add-parentheses
0242-valid-anagram
0344-reverse-string
0387-first-unique-character-in-a-string
0389-find-the-difference
0500-keyboard-row
0539-minimum-time-difference
0557-reverse-words-in-a-string-iii
0567-permutation-in-string
0782-jewels-and-stones
0844-backspace-string-compare	Easy
0889-buddy-strings
0920-uncommon-words-from-two-sentences
1205-defanging-an-ip-address
1302-delete-characters-to-make-fancy-string
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1737-maximum-nesting-depth-of-the-parentheses
1758-minimum-changes-to-make-alternating-binary-string	Easy
1786-count-the-number-of-consistent-strings
1797-goal-parser-interpretation
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1954-replace-all-digits-with-characters
2076-sum-of-digits-of-string-after-convert
2128-reverse-prefix-of-word
2137-final-value-of-variable-after-performing-operations
2154-minimum-moves-to-convert-string
2173-number-of-valid-words-in-a-sentence
2226-rings-and-rods
2235-capitalize-the-title
2292-counting-words-with-a-given-prefix
2406-decode-the-message
2427-first-letter-to-appear-twice
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2502-sort-the-people
2800-minimum-string-length-after-removing-substrings
2886-faulty-keyboard
3195-separate-black-and-white-balls
3396-valid-word
3412-permutation-difference-between-two-strings
3447-clear-digits

Hash Table

Problem Name	Difficulty
0001-two-sum
0003-longest-substring-without-repeating-characters
0013-roman-to-integer
0202-happy-number
0217-contains-duplicate
0219-contains-duplicate-ii
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
0387-first-unique-character-in-a-string
0389-find-the-difference
0500-keyboard-row
0567-permutation-in-string
0782-jewels-and-stones
0889-buddy-strings
0920-uncommon-words-from-two-sentences
1635-number-of-good-pairs
1786-count-the-number-of-consistent-strings
2116-count-number-of-pairs-with-absolute-difference-k
2159-two-out-of-three
2226-rings-and-rods
2308-divide-array-into-equal-pairs
2406-decode-the-message
2427-first-letter-to-appear-twice
2502-sort-the-people
2552-maximum-sum-of-distinct-subarrays-with-length-k
3227-find-missing-and-repeated-values
3412-permutation-difference-between-two-strings
3488-closest-equal-element-queries	Medium
3656-minimum-number-of-operations-to-make-elements-in-array-distinct

Greedy

Problem Name	Difficulty
2148-minimum-number-of-moves-to-seat-everyone
2154-minimum-moves-to-convert-string
3195-separate-black-and-white-balls

Sorting

Problem Name	Difficulty
0217-contains-duplicate
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
0389-find-the-difference
0539-minimum-time-difference
1730-special-array-with-x-elements-greater-than-or-equal-x
2148-minimum-number-of-moves-to-seat-everyone
2502-sort-the-people
3471-minimum-average-of-smallest-and-largest-elements

Sliding Window

Problem Name	Difficulty
0003-longest-substring-without-repeating-characters
0219-contains-duplicate-ii
0567-permutation-in-string
1755-defuse-the-bomb
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2552-maximum-sum-of-distinct-subarrays-with-length-k

Divide and Conquer

Problem Name	Difficulty
0191-number-of-1-bits
0347-top-k-frequent-elements

Bit Manipulation

Problem Name	Difficulty
0136-single-number	Easy
0191-number-of-1-bits
0268-missing-number
0338-counting-bits	Easy
0389-find-the-difference
0476-number-complement
0861-flipping-an-image
1435-xor-queries-of-a-subarray
1786-count-the-number-of-consistent-strings
2159-two-out-of-three
2308-divide-array-into-equal-pairs
2427-first-letter-to-appear-twice

Heap (Priority Queue)

Problem Name	Difficulty
0347-top-k-frequent-elements
3555-final-array-state-after-k-multiplication-operations-i

Bucket Sort

Problem Name	Difficulty
0347-top-k-frequent-elements

Counting

Problem Name	Difficulty
0347-top-k-frequent-elements
0387-first-unique-character-in-a-string
0920-uncommon-words-from-two-sentences
1635-number-of-good-pairs
1708-design-parking-system
1786-count-the-number-of-consistent-strings
2116-count-number-of-pairs-with-absolute-difference-k
2308-divide-array-into-equal-pairs
2427-first-letter-to-appear-twice

Quickselect

Problem Name	Difficulty
0347-top-k-frequent-elements

Stack

Problem Name	Difficulty
0020-valid-parentheses
0636-exclusive-time-of-functions	Medium
0844-backspace-string-compare	Easy
1475-final-prices-with-a-special-discount-in-a-shop	Easy
1737-maximum-nesting-depth-of-the-parentheses
2128-reverse-prefix-of-word
2800-minimum-string-length-after-removing-substrings
3447-clear-digits

Two Pointers

Problem Name	Difficulty
0028-find-the-index-of-the-first-occurrence-in-a-string
0125-valid-palindrome
0202-happy-number
0283-move-zeroes
0344-reverse-string
0557-reverse-words-in-a-string-iii
0567-permutation-in-string
0844-backspace-string-compare	Easy
0861-flipping-an-image
0876-middle-of-the-linked-list	Easy
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
2128-reverse-prefix-of-word
2551-apply-operations-to-an-array
3195-separate-black-and-white-balls
3471-minimum-average-of-smallest-and-largest-elements

Dynamic Programming

Problem Name	Difficulty
0118-pascals-triangle	Easy
0241-different-ways-to-add-parentheses
0338-counting-bits	Easy

Recursion

Problem Name	Difficulty
0002-add-two-numbers
0241-different-ways-to-add-parentheses
0326-power-of-three

Memoization

Problem Name	Difficulty
0241-different-ways-to-add-parentheses

Linked List

Problem Name	Difficulty
0002-add-two-numbers
0083-remove-duplicates-from-sorted-list
0876-middle-of-the-linked-list	Easy

Trie

Problem Name	Difficulty
0014-longest-common-prefix

String Matching

Problem Name	Difficulty
0028-find-the-index-of-the-first-occurrence-in-a-string
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
2292-counting-words-with-a-given-prefix

Design

Problem Name	Difficulty
1708-design-parking-system

Interactive

Problem Name	Difficulty
0374-guess-number-higher-or-lower

Queue

Problem Name	Difficulty
0387-first-unique-character-in-a-string

Counting Sort

Problem Name	Difficulty
2148-minimum-number-of-moves-to-seat-everyone

Monotonic Stack

Problem Name	Difficulty
1475-final-prices-with-a-special-discount-in-a-shop	Easy