coding-grind

Efficient algorithm implementations for technical skill enhancement.

LeetCode Topics

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
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
0036-valid-sudoku
0041-first-missing-positive
0042-trapping-rain-water
0048-rotate-image
0054-spiral-matrix
0056-merge-intervals
0057-insert-interval
0059-spiral-matrix-ii
0066-plus-one
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0078-subsets
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0121-best-time-to-buy-and-sell-stock
0134-gas-station
0135-candy
0136-single-number
0153-find-minimum-in-rotated-sorted-array
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
0238-product-of-array-except-self
0240-search-a-2d-matrix-ii
0260-single-number-iii
0268-missing-number
0274-h-index
0283-move-zeroes
0287-find-the-duplicate-number
0289-game-of-life
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0396-rotate-function
0442-find-all-duplicates-in-an-array
0463-island-perimeter
0485-max-consecutive-ones
0496-next-greater-element-i
0540-single-element-in-a-sorted-array
0822-unique-morse-code-words
0830-largest-triangle-area
0861-flipping-an-image
0890-lemonade-change
0932-monotonic-array
0965-unique-email-addresses
1018-largest-perimeter-triangle
1019-squares-of-a-sorted-array
1037-minimum-number-of-k-consecutive-bit-flips
1145-number-of-submatrices-that-sum-to-target
1210-mean-of-array-after-removing-some-elements
1227-number-of-equivalent-domino-pairs
1242-matrix-block-sum
1293-three-consecutive-odds
1310-watering-plants
1349-check-if-it-is-a-straight-line
1370-count-number-of-nice-subarrays
1580-shuffle-the-array
1584-average-salary-excluding-the-minimum-and-maximum-salary
1603-running-sum-of-1d-array
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1626-can-make-arithmetic-progression-from-sequence
1635-number-of-good-pairs
1677-matrix-diagonal-sum
1786-count-the-number-of-consistent-strings
1791-richest-customer-wealth
1839-decode-xored-array
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1950-sign-of-the-product-of-an-array
1975-minimum-distance-to-the-target-element
1988-minimize-maximum-pair-sum-in-array
2048-build-array-from-permutation
2137-final-value-of-variable-after-performing-operations
2144-maximum-difference-between-increasing-elements
2148-minimum-number-of-moves-to-seat-everyone
2244-number-of-laser-beams-in-a-bank
2265-partition-array-according-to-given-pivot
2269-count-elements-with-strictly-smaller-and-greater-elements
2271-rearrange-array-elements-by-sign
2387-partition-array-such-that-maximum-difference-is-k
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2519-find-the-original-array-of-prefix-xor
2542-average-value-of-even-numbers-that-are-divisible-by-three
2727-number-of-senior-citizens
3143-longest-unequal-adjacent-groups-subsequence-i
3194-find-words-containing-character
3321-type-of-triangle
3373-maximum-prime-difference
3430-count-days-without-meetings
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3515-find-if-digit-game-can-be-won
3581-the-two-sneaky-numbers-of-digitville
3704-count-partitions-with-even-sum-difference
3723-sum-of-good-numbers
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3778-transform-array-by-parity
3822-fill-a-special-grid
3832-minimum-cost-to-reach-every-position
3846-minimum-operations-to-make-array-sum-divisible-by-k

Simulation

0054-spiral-matrix
0059-spiral-matrix-ii
0067-add-binary
0258-add-digits
0289-game-of-life
0412-fizz-buzz
0537-complex-number-multiplication
0657-robot-return-to-origin
0861-flipping-an-image
1310-watering-plants
1708-design-parking-system
2048-build-array-from-permutation
2137-final-value-of-variable-after-performing-operations
2260-divide-a-string-into-groups-of-size-k
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
3511-find-the-winning-player-in-coin-game
3768-check-if-digits-are-equal-in-string-after-operations-i

Math

0007-reverse-integer
0009-palindrome-number
0048-rotate-image
0050-powx-n
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0172-factorial-trailing-zeroes
0189-rotate-array
0202-happy-number
0204-count-primes
0231-power-of-two
0258-add-digits
0263-ugly-number
0264-ugly-number-ii
0268-missing-number
0292-nim-game
0319-bulb-switcher
0326-power-of-three
0342-power-of-four
0367-valid-perfect-square
0371-sum-of-two-integers
0396-rotate-function
0412-fizz-buzz
0441-arranging-coins
0537-complex-number-multiplication
0767-prime-number-of-set-bits-in-binary-representation
0830-largest-triangle-area
0900-reordered-power-of-2
1013-fibonacci-number
1018-largest-perimeter-triangle
1086-divisor-game
1260-day-of-the-year
1349-check-if-it-is-a-straight-line
1370-count-number-of-nice-subarrays
1406-subtract-the-product-and-sum-of-digits-of-an-integer
1630-count-odd-numbers-in-an-interval-range
1635-number-of-good-pairs
1950-sign-of-the-product-of-an-array
2244-number-of-laser-beams-in-a-bank
2383-add-two-integers
2481-strictly-palindromic-number
2491-smallest-even-multiple
2542-average-value-of-even-numbers-that-are-divisible-by-three
2556-convert-the-temperature
2704-maximum-difference-by-remapping-a-digit
2752-sum-multiples
2812-find-the-maximum-achievable-number
3172-divisible-and-non-divisible-sums-difference
3321-type-of-triangle
3373-maximum-prime-difference
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3511-find-the-winning-player-in-coin-game
3515-find-if-digit-game-can-be-won
3567-convert-date-to-binary
3581-the-two-sneaky-numbers-of-digitville
3629-total-characters-in-string-after-transformations-i
3704-count-partitions-with-even-sum-difference
3768-check-if-digits-are-equal-in-string-after-operations-i
3817-maximum-containers-on-a-ship
3830-find-closest-person
3846-minimum-operations-to-make-array-sum-divisible-by-k
3859-maximum-product-of-two-digits

Matrix

0036-valid-sudoku
0048-rotate-image
0054-spiral-matrix
0059-spiral-matrix-ii
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0240-search-a-2d-matrix-ii
0289-game-of-life
0463-island-perimeter
0861-flipping-an-image
1145-number-of-submatrices-that-sum-to-target
1242-matrix-block-sum
1677-matrix-diagonal-sum
1791-richest-customer-wealth
2244-number-of-laser-beams-in-a-bank
3822-fill-a-special-grid

Two Pointers

0011-container-with-most-water
0026-remove-duplicates-from-sorted-array
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0042-trapping-rain-water
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0202-happy-number
0283-move-zeroes
0287-find-the-duplicate-number
0344-reverse-string
0345-reverse-vowels-of-a-string
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0392-is-subsequence
0861-flipping-an-image
0953-reverse-only-letters
1019-squares-of-a-sorted-array
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1894-merge-strings-alternately
1988-minimize-maximum-pair-sum-in-array
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2481-strictly-palindromic-number
3683-find-the-lexicographically-largest-string-from-the-box-i

String

0014-longest-common-prefix
0020-valid-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0032-longest-valid-parentheses
0058-length-of-last-word
0067-add-binary
0125-valid-palindrome
0151-reverse-words-in-a-string
0205-isomorphic-strings
0242-valid-anagram
0290-word-pattern
0344-reverse-string
0345-reverse-vowels-of-a-string
0383-ransom-note
0389-find-the-difference
0392-is-subsequence
0409-longest-palindrome
0412-fizz-buzz
0520-detect-capital
0537-complex-number-multiplication
0657-robot-return-to-origin
0742-to-lower-case
0782-jewels-and-stones
0800-letter-case-permutation
0812-rotate-string
0822-unique-morse-code-words
0953-reverse-only-letters
0965-unique-email-addresses
1160-letter-tile-possibilities
1205-defanging-an-ip-address
1260-day-of-the-year
1786-count-the-number-of-consistent-strings
1807-partitioning-into-minimum-number-of-deci-binary-numbers
1894-merge-strings-alternately
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
2137-final-value-of-variable-after-performing-operations
2244-number-of-laser-beams-in-a-bank
2260-divide-a-string-into-groups-of-size-k
2406-decode-the-message
2727-number-of-senior-citizens
3143-longest-unequal-adjacent-groups-subsequence-i
3194-find-words-containing-character
3379-score-of-a-string
3567-convert-date-to-binary
3629-total-characters-in-string-after-transformations-i
3683-find-the-lexicographically-largest-string-from-the-box-i
3753-maximum-difference-between-even-and-odd-frequency-i
3768-check-if-digits-are-equal-in-string-after-operations-i

Hash Table

0001-two-sum
0036-valid-sudoku
0041-first-missing-positive
0073-set-matrix-zeroes
0141-linked-list-cycle
0169-majority-element
0202-happy-number
0205-isomorphic-strings
0217-contains-duplicate
0242-valid-anagram
0264-ugly-number-ii
0268-missing-number
0290-word-pattern
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0383-ransom-note
0389-find-the-difference
0409-longest-palindrome
0442-find-all-duplicates-in-an-array
0496-next-greater-element-i
0782-jewels-and-stones
0822-unique-morse-code-words
0900-reordered-power-of-2
0965-unique-email-addresses
1145-number-of-submatrices-that-sum-to-target
1160-letter-tile-possibilities
1227-number-of-equivalent-domino-pairs
1370-count-number-of-nice-subarrays
1635-number-of-good-pairs
1786-count-the-number-of-consistent-strings
2406-decode-the-message
2473-max-sum-of-a-pair-with-equal-sum-of-digits
3581-the-two-sneaky-numbers-of-digitville
3629-total-characters-in-string-after-transformations-i
3753-maximum-difference-between-even-and-odd-frequency-i

Sorting

0056-merge-intervals
0088-merge-sorted-array
0169-majority-element
0217-contains-duplicate
0242-valid-anagram
0268-missing-number
0274-h-index
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0389-find-the-difference
0900-reordered-power-of-2
1018-largest-perimeter-triangle
1019-squares-of-a-sorted-array
1210-mean-of-array-after-removing-some-elements
1584-average-salary-excluding-the-minimum-and-maximum-salary
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1626-can-make-arithmetic-progression-from-sequence
1988-minimize-maximum-pair-sum-in-array
2148-minimum-number-of-moves-to-seat-everyone
2269-count-elements-with-strictly-smaller-and-greater-elements
2387-partition-array-such-that-maximum-difference-is-k
2473-max-sum-of-a-pair-with-equal-sum-of-digits
3321-type-of-triangle
3430-count-days-without-meetings
3778-transform-array-by-parity
3859-maximum-product-of-two-digits

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
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0240-search-a-2d-matrix-ii
0268-missing-number
0287-find-the-duplicate-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0367-valid-perfect-square
0441-arranging-coins
0540-single-element-in-a-sorted-array
1621-number-of-subsequences-that-satisfy-the-given-sum-condition

Divide and Conquer

0004-median-of-two-sorted-arrays
0169-majority-element
0191-number-of-1-bits
0240-search-a-2d-matrix-ii
0347-top-k-frequent-elements
3822-fill-a-special-grid

Counting

0169-majority-element
0347-top-k-frequent-elements
0383-ransom-note
0900-reordered-power-of-2
1160-letter-tile-possibilities
1227-number-of-equivalent-domino-pairs
1635-number-of-good-pairs
1708-design-parking-system
1786-count-the-number-of-consistent-strings
2269-count-elements-with-strictly-smaller-and-greater-elements
3629-total-characters-in-string-after-transformations-i
3753-maximum-difference-between-even-and-odd-frequency-i
3778-transform-array-by-parity

Bit Manipulation

0067-add-binary
0078-subsets
0136-single-number
0191-number-of-1-bits
0231-power-of-two
0260-single-number-iii
0268-missing-number
0287-find-the-duplicate-number
0338-counting-bits
0342-power-of-four
0371-sum-of-two-integers
0389-find-the-difference
0461-hamming-distance
0476-number-complement
0767-prime-number-of-set-bits-in-binary-representation
0800-letter-case-permutation
0861-flipping-an-image
1037-minimum-number-of-k-consecutive-bit-flips
1786-count-the-number-of-consistent-strings
1839-decode-xored-array
2519-find-the-original-array-of-prefix-xor
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Number Theory

0204-count-primes
0258-add-digits
2491-smallest-even-multiple
3373-maximum-prime-difference
3768-check-if-digits-are-equal-in-string-after-operations-i

Brainteaser

0292-nim-game
0319-bulb-switcher
1086-divisor-game
2481-strictly-palindromic-number

Game Theory

0292-nim-game
1086-divisor-game
3511-find-the-winning-player-in-coin-game

Dynamic Programming

0032-longest-valid-parentheses
0042-trapping-rain-water
0070-climbing-stairs
0121-best-time-to-buy-and-sell-stock
0264-ugly-number-ii
0338-counting-bits
0392-is-subsequence
0396-rotate-function
1013-fibonacci-number
1086-divisor-game
3143-longest-unequal-adjacent-groups-subsequence-i
3629-total-characters-in-string-after-transformations-i

Recursion

0021-merge-two-sorted-lists
0050-powx-n
0231-power-of-two
0326-power-of-three
0342-power-of-four
1013-fibonacci-number

Enumeration

0204-count-primes
0900-reordered-power-of-2
3683-find-the-lexicographically-largest-string-from-the-box-i

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
1037-minimum-number-of-k-consecutive-bit-flips
1145-number-of-submatrices-that-sum-to-target
1242-matrix-block-sum
1370-count-number-of-nice-subarrays
1603-running-sum-of-1d-array
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3704-count-partitions-with-even-sum-difference

Stack

0020-valid-parentheses
0032-longest-valid-parentheses
0042-trapping-rain-water
0094-binary-tree-inorder-traversal
0496-next-greater-element-i

Monotonic Stack

0042-trapping-rain-water
0496-next-greater-element-i

Memoization

0070-climbing-stairs
1013-fibonacci-number

Greedy

0011-container-with-most-water
0134-gas-station
0135-candy
0409-longest-palindrome
0890-lemonade-change
1018-largest-perimeter-triangle
1807-partitioning-into-minimum-number-of-deci-binary-numbers
1988-minimize-maximum-pair-sum-in-array
2148-minimum-number-of-moves-to-seat-everyone
2387-partition-array-such-that-maximum-difference-is-k
2704-maximum-difference-by-remapping-a-digit
3143-longest-unequal-adjacent-groups-subsequence-i

Combinatorics

3768-check-if-digits-are-equal-in-string-after-operations-i

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
0812-rotate-string

Heap (Priority Queue)

0264-ugly-number-ii
0347-top-k-frequent-elements
2473-max-sum-of-a-pair-with-equal-sum-of-digits

Bucket Sort

0347-top-k-frequent-elements

Quickselect

0347-top-k-frequent-elements

Trie

0014-longest-common-prefix

Depth-First Search

0094-binary-tree-inorder-traversal
0463-island-perimeter

Breadth-First Search

0463-island-perimeter

Counting Sort

0274-h-index
2148-minimum-number-of-moves-to-seat-everyone

Linked List

0021-merge-two-sorted-lists
0083-remove-duplicates-from-sorted-list
0141-linked-list-cycle

Geometry

0830-largest-triangle-area
1349-check-if-it-is-a-straight-line

Sliding Window

0209-minimum-size-subarray-sum
1037-minimum-number-of-k-consecutive-bit-flips
1370-count-number-of-nice-subarrays
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Queue

1037-minimum-number-of-k-consecutive-bit-flips
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Backtracking

0078-subsets
0800-letter-case-permutation
1160-letter-tile-possibilities

Design

1708-design-parking-system

Tree

0094-binary-tree-inorder-traversal

Binary Tree

0094-binary-tree-inorder-traversal