LeetCode POTD Solutions

Welcome to my LeetCode POTD (Problem of the Day) solutions repository! Here, you'll find my solutions to the daily coding challenges on LeetCode.

Table of Contents

• Introduction
• Languages
• Directory Structure
• How to Contribute
• Connect with Me

Introduction

This repository contains my solutions to the LeetCode POTD problems. I regularly update it with new solutions as I work through the challenges. Feel free to explore and use the code for your reference.

Languages

• Python
• C++ (Learning in Progress)

Directory Structure

• [Problem Number]: Each directory corresponds to a specific LeetCode POTD problem. Inside each directory, you'll find the solution file(s) along with any additional resources or explanations.

How to Contribute

If you have a better solution or want to add explanations to existing ones, feel free to contribute! Here's how you can do it:

1. Fork the repository.
2. Create a new branch for your feature: git checkout -b feature/new-solution.
3. Commit your changes: git commit -m 'Added a new solution for Problem X'.
4. Push to the branch: git push origin feature/new-solution.
5. Submit a pull request.

Connect with Me

Let's connect! Feel free to reach out on LinkedIn. I'm open to discussions, collaborations, or just a friendly chat about coding and technology.

Happy Coding! 🚀

LeetCode Topics

Array

0073-set-matrix-zeroes
0075-sort-colors
0368-largest-divisible-subset
0407-trapping-rain-water-ii
0689-maximum-sum-of-3-non-overlapping-subarrays
0797-rabbits-in-forest
0905-length-of-longest-fibonacci-subsequence
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0945-snakes-and-ladders
0952-word-subsets
1025-minimum-cost-for-tickets
1049-minimum-domino-rotations-for-equal-row
1063-best-sightseeing-pair
1227-number-of-equivalent-domino-pairs
1293-three-consecutive-odds
1335-maximum-candies-allocated-to-k-children
1364-tuple-with-same-product
1396-count-servers-that-communicate
1477-product-of-the-last-k-numbers
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1524-string-matching-in-an-array
1631-number-of-sub-arrays-with-odd-sum
1656-count-good-triplets
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1819-construct-the-lexicographically-largest-valid-sequence
1849-maximum-absolute-sum-of-any-subarray
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
1993-sum-of-all-subset-xor-totals
2048-build-array-from-permutation
2107-find-unique-binary-string
2180-maximum-number-of-tasks-you-can-assign
2215-finding-3-digit-even-numbers
2249-count-the-hidden-sequences
2262-solving-questions-with-brainpower
2265-partition-array-according-to-given-pivot
2277-count-equal-and-divisible-pairs-in-an-array
2280-count-good-triplets-in-an-array
2292-counting-words-with-a-given-prefix
2358-number-of-ways-to-split-array
2394-count-subarrays-with-score-less-than-k
2448-count-number-of-bad-pairs
2465-shifting-letters-ii
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2527-count-subarrays-with-fixed-bounds
2533-bitwise-xor-of-all-pairings
2551-apply-operations-to-an-array
2564-most-profitable-path-in-a-tree
2614-maximum-count-of-positive-integer-and-negative-integer
2626-count-the-number-of-good-subarrays
2665-minimum-time-to-repair-cars
2681-put-marbles-in-bags
2690-house-robber-iv
2691-count-vowel-strings-in-ranges
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
2764-maximum-number-of-fish-in-a-grid
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
2856-count-complete-subarrays-in-an-array
2915-count-of-interesting-subarrays
3152-maximum-value-of-an-ordered-triplet-ii
3154-maximum-value-of-an-ordered-triplet-i
3194-find-words-containing-character
3213-count-subarrays-where-max-element-appears-at-least-k-times
3219-make-lexicographically-smallest-array-by-swapping-elements
3227-find-missing-and-repeated-values
3307-find-the-maximum-sum-of-node-values
3309-count-prefix-and-suffix-pairs-i
3321-type-of-triangle
3332-minimum-operations-to-exceed-threshold-value-ii
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3429-special-array-i
3434-find-the-number-of-distinct-colors-among-the-balls
3483-alternating-groups-ii
3621-minimum-operations-to-make-array-values-equal-to-k
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3639-zero-array-transformation-i
3643-zero-array-transformation-ii
3685-count-subarrays-of-length-three-with-a-condition

Dynamic Programming

0368-largest-divisible-subset
0689-maximum-sum-of-3-non-overlapping-subarrays
0806-domino-and-tromino-tiling
0905-length-of-longest-fibonacci-subsequence
1025-minimum-cost-for-tickets
1063-best-sightseeing-pair
1170-shortest-common-supersequence
1631-number-of-sub-arrays-with-odd-sum
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1849-maximum-absolute-sum-of-any-subarray
1986-largest-color-value-in-a-directed-graph
2061-painting-a-grid-with-three-different-colors
2262-solving-questions-with-brainpower
2415-count-the-number-of-ideal-arrays
2562-count-ways-to-build-good-strings
3243-count-the-number-of-powerful-integers
3307-find-the-maximum-sum-of-node-values
3629-total-characters-in-string-after-transformations-i
3637-count-number-of-balanced-permutations

String

0038-count-and-say
0952-word-subsets
1093-recover-a-tree-from-preorder-traversal
1160-letter-tile-possibilities
1170-shortest-common-supersequence
1460-number-of-substrings-containing-all-three-characters
1502-construct-k-palindrome-strings
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1524-string-matching-in-an-array
1537-maximum-score-after-splitting-a-string
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1915-check-if-one-string-swap-can-make-strings-equal
2021-remove-all-occurrences-of-a-substring
2059-unique-length-3-palindromic-subsequences
2107-find-unique-binary-string
2221-check-if-a-parentheses-string-can-be-valid
2292-counting-words-with-a-given-prefix
2456-construct-smallest-number-from-di-string
2465-shifting-letters-ii
2691-count-vowel-strings-in-ranges
3194-find-words-containing-character
3243-count-the-number-of-powerful-integers
3309-count-prefix-and-suffix-pairs-i
3445-lexicographically-minimum-string-after-removing-stars
3447-clear-digits
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3629-total-characters-in-string-after-transformations-i
3637-count-number-of-balanced-permutations
3754-maximum-manhattan-distance-after-k-changes

Prefix Sum

1477-product-of-the-last-k-numbers
1537-maximum-score-after-splitting-a-string
1631-number-of-sub-arrays-with-odd-sum
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
2059-unique-length-3-palindromic-subsequences
2249-count-the-hidden-sequences
2358-number-of-ways-to-split-array
2394-count-subarrays-with-score-less-than-k
2465-shifting-letters-ii
2691-count-vowel-strings-in-ranges
2915-count-of-interesting-subarrays
3639-zero-array-transformation-i
3643-zero-array-transformation-ii

Hash Table

0073-set-matrix-zeroes
0797-rabbits-in-forest
0905-length-of-longest-fibonacci-subsequence
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0952-word-subsets
1160-letter-tile-possibilities
1218-lowest-common-ancestor-of-deepest-leaves
1227-number-of-equivalent-domino-pairs
1364-tuple-with-same-product
1387-find-elements-in-a-contaminated-binary-tree
1460-number-of-substrings-containing-all-three-characters
1500-count-largest-group
1502-construct-k-palindrome-strings
1915-check-if-one-string-swap-can-make-strings-equal
1986-largest-color-value-in-a-directed-graph
2059-unique-length-3-palindromic-subsequences
2107-find-unique-binary-string
2215-finding-3-digit-even-numbers
2434-design-a-number-container-system
2448-count-number-of-bad-pairs
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2626-count-the-number-of-good-subarrays
2707-merge-two-2d-arrays-by-summing-values
2766-find-the-prefix-common-array-of-two-arrays
2856-count-complete-subarrays-in-an-array
2915-count-of-interesting-subarrays
3227-find-missing-and-repeated-values
3434-find-the-number-of-distinct-colors-among-the-balls
3445-lexicographically-minimum-string-after-removing-stars
3548-find-the-count-of-good-integers
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3621-minimum-operations-to-make-array-values-equal-to-k
3629-total-characters-in-string-after-transformations-i
3754-maximum-manhattan-distance-after-k-changes

Bit Manipulation

1993-sum-of-all-subset-xor-totals
2059-unique-length-3-palindromic-subsequences
2509-minimize-xor
2533-bitwise-xor-of-all-pairings
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
3307-find-the-maximum-sum-of-node-values

String Matching

1524-string-matching-in-an-array
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i

Trie

3309-count-prefix-and-suffix-pairs-i

Rolling Hash

3309-count-prefix-and-suffix-pairs-i

Hash Function

3309-count-prefix-and-suffix-pairs-i

Greedy

0797-rabbits-in-forest
1049-minimum-domino-rotations-for-equal-row
1502-construct-k-palindrome-strings
2180-maximum-number-of-tasks-you-can-assign
2221-check-if-a-parentheses-string-can-be-valid
2456-construct-smallest-number-from-di-string
2509-minimize-xor
2681-put-marbles-in-bags
3307-find-the-maximum-sum-of-node-values
3445-lexicographically-minimum-string-after-removing-stars

Counting

1160-letter-tile-possibilities
1227-number-of-equivalent-domino-pairs
1364-tuple-with-same-product
1396-count-servers-that-communicate
1502-construct-k-palindrome-strings
1915-check-if-one-string-swap-can-make-strings-equal
1986-largest-color-value-in-a-directed-graph
2448-count-number-of-bad-pairs
2614-maximum-count-of-positive-integer-and-negative-integer
3629-total-characters-in-string-after-transformations-i
3754-maximum-manhattan-distance-after-k-changes

Stack

2021-remove-all-occurrences-of-a-substring
2221-check-if-a-parentheses-string-can-be-valid
2456-construct-smallest-number-from-di-string
3445-lexicographically-minimum-string-after-removing-stars
3447-clear-digits

Brainteaser

2533-bitwise-xor-of-all-pairings

Breadth-First Search

0407-trapping-rain-water-ii
0684-redundant-connection
0820-find-eventual-safe-states
0945-snakes-and-ladders
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1396-count-servers-that-communicate
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1558-course-schedule-iv
2564-most-profitable-path-in-a-tree
2764-maximum-number-of-fish-in-a-grid
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i

Graph

0684-redundant-connection
0820-find-eventual-safe-states
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1558-course-schedule-iv
1986-largest-color-value-in-a-directed-graph
2246-maximum-employees-to-be-invited-to-a-meeting
2438-find-closest-node-to-given-two-nodes
2564-most-profitable-path-in-a-tree
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Heap (Priority Queue)

0407-trapping-rain-water-ii
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2434-design-a-number-container-system
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2681-put-marbles-in-bags
3332-minimum-operations-to-exceed-threshold-value-ii
3445-lexicographically-minimum-string-after-removing-stars
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Matrix

0073-set-matrix-zeroes
0407-trapping-rain-water-ii
0945-snakes-and-ladders
1396-count-servers-that-communicate
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2764-maximum-number-of-fish-in-a-grid
3227-find-missing-and-repeated-values
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Shortest Path

1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Depth-First Search

0684-redundant-connection
0820-find-eventual-safe-states
1093-recover-a-tree-from-preorder-traversal
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1396-count-servers-that-communicate
1558-course-schedule-iv
2246-maximum-employees-to-be-invited-to-a-meeting
2438-find-closest-node-to-given-two-nodes
2564-most-profitable-path-in-a-tree
2764-maximum-number-of-fish-in-a-grid
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i

Union Find

0684-redundant-connection
1396-count-servers-that-communicate
2764-maximum-number-of-fish-in-a-grid
3219-make-lexicographically-smallest-array-by-swapping-elements

Topological Sort

0820-find-eventual-safe-states
1558-course-schedule-iv
1986-largest-color-value-in-a-directed-graph
2246-maximum-employees-to-be-invited-to-a-meeting

Sorting

0075-sort-colors
0368-largest-divisible-subset
2180-maximum-number-of-tasks-you-can-assign
2215-finding-3-digit-even-numbers
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2681-put-marbles-in-bags
2699-count-the-number-of-fair-pairs
3219-make-lexicographically-smallest-array-by-swapping-elements
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle

Simulation

2021-remove-all-occurrences-of-a-substring
2048-build-array-from-permutation
2265-partition-array-according-to-given-pivot
2551-apply-operations-to-an-array
3332-minimum-operations-to-exceed-threshold-value-ii
3434-find-the-number-of-distinct-colors-among-the-balls
3447-clear-digits

Design

1387-find-elements-in-a-contaminated-binary-tree
1477-product-of-the-last-k-numbers
2434-design-a-number-container-system

Ordered Set

2280-count-good-triplets-in-an-array
2434-design-a-number-container-system

Math

0368-largest-divisible-subset
0797-rabbits-in-forest
1477-product-of-the-last-k-numbers
1500-count-largest-group
1631-number-of-sub-arrays-with-odd-sum
1889-check-if-number-is-a-sum-of-powers-of-three
1993-sum-of-all-subset-xor-totals
2050-count-good-numbers
2415-count-the-number-of-ideal-arrays
2448-count-number-of-bad-pairs
2610-closest-prime-numbers-in-range
2649-count-total-number-of-colored-cells
2802-find-the-punishment-number-of-an-integer
2998-count-symmetric-integers
3172-divisible-and-non-divisible-sums-difference
3201-distribute-candies-among-children-ii
3227-find-missing-and-repeated-values
3243-count-the-number-of-powerful-integers
3321-type-of-triangle
3548-find-the-count-of-good-integers
3629-total-characters-in-string-after-transformations-i
3637-count-number-of-balanced-permutations
3754-maximum-manhattan-distance-after-k-changes

Data Stream

1477-product-of-the-last-k-numbers

Backtracking

1160-letter-tile-possibilities
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1819-construct-the-lexicographically-largest-valid-sequence
1993-sum-of-all-subset-xor-totals
2107-find-unique-binary-string
2456-construct-smallest-number-from-di-string
2802-find-the-punishment-number-of-an-integer

Tree

0925-construct-binary-tree-from-preorder-and-postorder-traversal
1093-recover-a-tree-from-preorder-traversal
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
2564-most-profitable-path-in-a-tree
3307-find-the-maximum-sum-of-node-values
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i

Binary Tree

0925-construct-binary-tree-from-preorder-and-postorder-traversal
1093-recover-a-tree-from-preorder-traversal
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree

Divide and Conquer

0925-construct-binary-tree-from-preorder-and-postorder-traversal
2280-count-good-triplets-in-an-array

Two Pointers

0075-sort-colors
2265-partition-array-according-to-given-pivot
2551-apply-operations-to-an-array
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values

Number Theory

2415-count-the-number-of-ideal-arrays
2610-closest-prime-numbers-in-range

Sliding Window

1460-number-of-substrings-containing-all-three-characters
2394-count-subarrays-with-score-less-than-k
2527-count-subarrays-with-fixed-bounds
2626-count-the-number-of-good-subarrays
2856-count-complete-subarrays-in-an-array
3213-count-subarrays-where-max-element-appears-at-least-k-times
3483-alternating-groups-ii
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii

Binary Search

1335-maximum-candies-allocated-to-k-children
2180-maximum-number-of-tasks-you-can-assign
2280-count-good-triplets-in-an-array
2394-count-subarrays-with-score-less-than-k
2614-maximum-count-of-positive-integer-and-negative-integer
2665-minimum-time-to-repair-cars
2690-house-robber-iv
2699-count-the-number-of-fair-pairs
3643-zero-array-transformation-ii

Combinatorics

1993-sum-of-all-subset-xor-totals
2415-count-the-number-of-ideal-arrays
3201-distribute-candies-among-children-ii
3548-find-the-count-of-good-integers
3637-count-number-of-balanced-permutations

Enumeration

1656-count-good-triplets
1993-sum-of-all-subset-xor-totals
2215-finding-3-digit-even-numbers
2998-count-symmetric-integers
3201-distribute-candies-among-children-ii
3548-find-the-count-of-good-integers

Recursion

2050-count-good-numbers

Binary Indexed Tree

2280-count-good-triplets-in-an-array

Segment Tree

2280-count-good-triplets-in-an-array

Merge Sort

2280-count-good-triplets-in-an-array

Queue

2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds

Monotonic Queue

2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds

Memoization

1986-largest-color-value-in-a-directed-graph