LeetCode Solutions Repository

🎉 Welcome to my interactive LeetCode solutions repository! Here, we dive deep into a world of coding challenges, with solutions carefully curated for various LeetCode problems, organized by topic and difficulty level. Whether you're gearing up for intense coding interviews or simply on a quest to level up your algorithmic prowess, you're in for a treat!

Explore the Codebase

This repository is a treasure trove of solutions, and I've expressed my creativity in multiple programming languages, including but not limited to:

• 🖥️ C++

Each solution comes with a story, thoroughly documented, unveiling the approach, shedding light on time and space complexity, and sharing those magical key insights that make the problems conquerable. My code isn't just efficient, it's elegant too. Dive in, learn, and if you've got that itch to enhance or provide alternate solutions, I'm all ears! Feel free to open a pull request. Collaboration fuels our growth!

Let's Code Together!

Contributions are the heartbeat of this repository! If you've got a mind-bending better solution, sniffed out a sneaky bug, or want to introduce a new challenge, don't hold back - submit that pull request. Just ensure you groove with our established coding style and shower us with a crystal-clear explanation of your solution. Together, we'll craft this repository into a haven for the entire LeetCode community.

Keep the Conversation Flowing

This isn't a one-way street, it's a bustling marketplace of ideas! Got thoughts to share? Feedback to provide? I'm all ears, and my inbox is eagerly waiting. Ping me at prashantkumarrai8@gmail.com, and let's keep the flames of learning burning bright!

Now, enough chit-chat. Let's dive into these coding challenges and emerge as coding wizards! 🚀

LeetCode Topics

Depth-First Search

Problem Name	Difficulty
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0124-binary-tree-maximum-path-sum
0145-binary-tree-postorder-traversal
0236-lowest-common-ancestor-of-a-binary-tree
0386-lexicographical-numbers
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0893-all-nodes-distance-k-in-binary-tree
0984-most-stones-removed-with-same-row-or-column
1029-vertical-order-traversal-of-a-binary-tree
1207-delete-nodes-and-return-forest
1350-remove-sub-folders-from-the-filesystem
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1484-linked-list-in-binary-tree
1691-minimum-number-of-days-to-disconnect-island
1753-path-with-minimum-effort
2035-count-sub-islands
2439-longest-cycle-in-a-graph
2461-amount-of-time-for-binary-tree-to-be-infected

Breadth-First Search

Problem Name	Difficulty
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0127-word-ladder
0662-maximum-width-of-binary-tree
0893-all-nodes-distance-k-in-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1171-shortest-path-in-binary-matrix
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1484-linked-list-in-binary-tree
1691-minimum-number-of-days-to-disconnect-island
1753-path-with-minimum-effort
2035-count-sub-islands
2171-second-minimum-time-to-reach-destination
2461-amount-of-time-for-binary-tree-to-be-infected

Graph

Problem Name	Difficulty
0984-most-stones-removed-with-same-row-or-column
1325-path-with-maximum-probability
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1701-remove-max-number-of-edges-to-keep-graph-fully-traversable
2171-second-minimum-time-to-reach-destination
2439-longest-cycle-in-a-graph
2678-design-graph-with-shortest-path-calculator

Topological Sort

Problem Name	Difficulty
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
2439-longest-cycle-in-a-graph

Linked List

Problem Name	Difficulty
0138-copy-list-with-random-pointer
0234-palindrome-linked-list
0859-design-circular-deque
1484-linked-list-in-binary-tree
2299-merge-nodes-in-between-zeros

Simulation

Problem Name	Difficulty
0906-walking-robot-simulation
1667-find-kth-bit-in-nth-binary-string
1951-find-the-winner-of-the-circular-game
2006-find-the-student-that-will-replace-the-chalk
2299-merge-nodes-in-between-zeros
2343-count-unguarded-cells-in-the-grid
2692-take-gifts-from-the-richest-pile

Array

Problem Name	Difficulty
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0049-group-anagrams
0056-merge-intervals
0066-plus-one
0073-set-matrix-zeroes
0081-search-in-rotated-sorted-array-ii
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
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
0179-largest-number
0309-best-time-to-buy-and-sell-stock-with-cooldown
0312-burst-balloons
0416-partition-equal-subset-sum
0455-assign-cookies
0494-target-sum
0523-continuous-subarray-sum
0539-minimum-time-difference
0540-single-element-in-a-sorted-array
0560-subarray-sum-equals-k
0632-smallest-range-covering-elements-from-k-lists
0713-subarray-product-less-than-k
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0719-find-k-th-smallest-pair-distance
0729-my-calendar-i
0731-my-calendar-ii
0797-rabbits-in-forest
0859-design-circular-deque
0890-lemonade-change
0906-walking-robot-simulation
0961-n-repeated-element-in-size-2n-array
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1121-partition-array-for-maximum-sum
1171-shortest-path-in-binary-matrix
1207-delete-nodes-and-return-forest
1266-minimum-time-visiting-all-points
1325-path-with-maximum-probability
1350-remove-sub-folders-from-the-filesystem
1370-count-number-of-nice-subarrays
1390-four-divisors
1402-count-square-submatrices-with-all-ones
1458-max-dot-product-of-two-subsequences
1468-check-if-n-and-its-double-exist
1511-count-number-of-teams
1538-maximum-points-you-can-obtain-from-cards
1586-longest-subarray-of-1s-after-deleting-one-element
1615-range-sum-of-sorted-subarray-sums
1620-check-if-array-pairs-are-divisible-by-k
1646-kth-missing-positive-number
1669-minimum-cost-to-cut-a-stick
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1691-minimum-number-of-days-to-disconnect-island
1694-make-sum-divisible-by-p
1720-crawler-log-folder
1753-path-with-minimum-effort
1895-largest-magic-square
1951-find-the-winner-of-the-circular-game
1972-rotating-the-box
1977-minimum-interval-to-include-each-query
1983-maximum-population-year
2006-find-the-student-that-will-replace-the-chalk
2035-count-sub-islands
2054-the-number-of-the-smallest-unoccupied-chair
2067-maximum-number-of-points-with-cost
2148-minimum-number-of-moves-to-seat-everyone
2343-count-unguarded-cells-in-the-grid
2488-divide-intervals-into-minimum-number-of-groups
2503-longest-subarray-with-maximum-bitwise-and
2552-maximum-sum-of-distinct-subarrays-with-length-k
2554-minimum-total-distance-traveled
2586-longest-square-streak-in-an-array
2616-maximal-score-after-applying-k-operations
2692-take-gifts-from-the-richest-pile
2699-count-the-number-of-fair-pairs
2716-prime-subtraction-operation
2943-maximize-area-of-square-hole-in-grid
3034-points-that-intersect-with-cars
3213-count-subarrays-where-max-element-appears-at-least-k-times
3278-find-the-number-of-ways-to-place-people-i
3329-find-the-length-of-the-longest-common-prefix
3453-separate-squares-i
3522-find-the-power-of-k-size-subarrays-i
3640-trionic-array-ii

Hash Table

Problem Name	Difficulty
0049-group-anagrams
0073-set-matrix-zeroes
0076-minimum-window-substring
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0127-word-ladder
0138-copy-list-with-random-pointer
0523-continuous-subarray-sum
0560-subarray-sum-equals-k
0567-permutation-in-string
0632-smallest-range-covering-elements-from-k-lists
0726-number-of-atoms
0797-rabbits-in-forest
0893-all-nodes-distance-k-in-binary-tree
0906-walking-robot-simulation
0961-n-repeated-element-in-size-2n-array
0966-binary-subarrays-with-sum
0984-most-stones-removed-with-same-row-or-column
1029-vertical-order-traversal-of-a-binary-tree
1207-delete-nodes-and-return-forest
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1468-check-if-n-and-its-double-exist
1473-find-the-longest-substring-containing-vowels-in-even-counts
1620-check-if-array-pairs-are-divisible-by-k
1694-make-sum-divisible-by-p
1715-split-a-string-into-the-max-number-of-unique-substrings
2054-the-number-of-the-smallest-unoccupied-chair
2461-amount-of-time-for-binary-tree-to-be-infected
2552-maximum-sum-of-distinct-subarrays-with-length-k
2586-longest-square-streak-in-an-array
3034-points-that-intersect-with-cars
3329-find-the-length-of-the-longest-common-prefix
3872-find-most-frequent-vowel-and-consonant

Prefix Sum

Problem Name	Difficulty
0523-continuous-subarray-sum
0560-subarray-sum-equals-k
0731-my-calendar-ii
0732-my-calendar-iii
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1473-find-the-longest-substring-containing-vowels-in-even-counts
1538-maximum-points-you-can-obtain-from-cards
1694-make-sum-divisible-by-p
1895-largest-magic-square
1983-maximum-population-year
2006-find-the-student-that-will-replace-the-chalk
2488-divide-intervals-into-minimum-number-of-groups
3034-points-that-intersect-with-cars

Math

Problem Name	Difficulty
0066-plus-one
0224-basic-calculator
0241-different-ways-to-add-parentheses
0273-integer-to-english-words
0523-continuous-subarray-sum
0539-minimum-time-difference
0564-find-the-closest-palindrome
0650-2-keys-keyboard
0762-prime-number-of-set-bits-in-binary-representation
0797-rabbits-in-forest
1266-minimum-time-visiting-all-points
1370-count-number-of-nice-subarrays
1390-four-divisors
1951-find-the-winner-of-the-circular-game
2716-prime-subtraction-operation
3278-find-the-number-of-ways-to-place-people-i
3830-find-closest-person

Sliding Window

Problem Name	Difficulty
0076-minimum-window-substring
0567-permutation-in-string
0632-smallest-range-covering-elements-from-k-lists
0713-subarray-product-less-than-k
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1538-maximum-points-you-can-obtain-from-cards
1586-longest-subarray-of-1s-after-deleting-one-element
2552-maximum-sum-of-distinct-subarrays-with-length-k
3213-count-subarrays-where-max-element-appears-at-least-k-times
3522-find-the-power-of-k-size-subarrays-i

Union Find

Problem Name	Difficulty
0984-most-stones-removed-with-same-row-or-column
1701-remove-max-number-of-edges-to-keep-graph-fully-traversable
1753-path-with-minimum-effort
2035-count-sub-islands

Greedy

Problem Name	Difficulty
0044-wildcard-matching
0122-best-time-to-buy-and-sell-stock-ii
0179-largest-number
0455-assign-cookies
0632-smallest-range-covering-elements-from-k-lists
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0797-rabbits-in-forest
0890-lemonade-change
0957-minimum-add-to-make-parentheses-valid
2095-minimum-number-of-swaps-to-make-the-string-balanced
2148-minimum-number-of-moves-to-seat-everyone
2488-divide-intervals-into-minimum-number-of-groups
2616-maximal-score-after-applying-k-operations
2716-prime-subtraction-operation
3195-separate-black-and-white-balls

Sorting

Problem Name	Difficulty
0049-group-anagrams
0056-merge-intervals
0179-largest-number
0455-assign-cookies
0539-minimum-time-difference
0632-smallest-range-covering-elements-from-k-lists
0719-find-k-th-smallest-pair-distance
0726-number-of-atoms
0761-special-binary-string
1029-vertical-order-traversal-of-a-binary-tree
1468-check-if-n-and-its-double-exist
1615-range-sum-of-sorted-subarray-sums
1669-minimum-cost-to-cut-a-stick
1977-minimum-interval-to-include-each-query
2148-minimum-number-of-moves-to-seat-everyone
2488-divide-intervals-into-minimum-number-of-groups
2554-minimum-total-distance-traveled
2586-longest-square-streak-in-an-array
2699-count-the-number-of-fair-pairs
2943-maximize-area-of-square-hole-in-grid
3278-find-the-number-of-ways-to-place-people-i

String

Problem Name	Difficulty
0005-longest-palindromic-substring
0014-longest-common-prefix
0028-find-the-index-of-the-first-occurrence-in-a-string
0044-wildcard-matching
0049-group-anagrams
0058-length-of-last-word
0072-edit-distance
0076-minimum-window-substring
0115-distinct-subsequences
0127-word-ladder
0132-palindrome-partitioning-ii
0179-largest-number
0214-shortest-palindrome
0224-basic-calculator
0241-different-ways-to-add-parentheses
0273-integer-to-english-words
0516-longest-palindromic-subsequence
0539-minimum-time-difference
0564-find-the-closest-palindrome
0567-permutation-in-string
0583-delete-operation-for-two-strings
0712-minimum-ascii-delete-sum-for-two-strings
0726-number-of-atoms
0761-special-binary-string
0957-minimum-add-to-make-parentheses-valid
1197-parsing-a-boolean-expression
1250-longest-common-subsequence
1350-remove-sub-folders-from-the-filesystem
1437-minimum-insertion-steps-to-make-a-string-palindrome
1460-number-of-substrings-containing-all-three-characters
1473-find-the-longest-substring-containing-vowels-in-even-counts
1508-longest-happy-prefix
1667-find-kth-bit-in-nth-binary-string
1715-split-a-string-into-the-max-number-of-unique-substrings
1720-crawler-log-folder
1756-minimum-deletions-to-make-string-balanced
2095-minimum-number-of-swaps-to-make-the-string-balanced
2414-move-pieces-to-obtain-a-string
2580-circular-sentence
3174-minimum-number-of-changes-to-make-binary-string-beautiful
3195-separate-black-and-white-balls
3329-find-the-length-of-the-longest-common-prefix
3872-find-most-frequent-vowel-and-consonant

Dynamic Programming

Problem Name	Difficulty
0005-longest-palindromic-substring
0044-wildcard-matching
0072-edit-distance
0115-distinct-subsequences
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
0124-binary-tree-maximum-path-sum
0132-palindrome-partitioning-ii
0241-different-ways-to-add-parentheses
0309-best-time-to-buy-and-sell-stock-with-cooldown
0312-burst-balloons
0416-partition-equal-subset-sum
0494-target-sum
0516-longest-palindromic-subsequence
0583-delete-operation-for-two-strings
0650-2-keys-keyboard
0712-minimum-ascii-delete-sum-for-two-strings
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
1121-partition-array-for-maximum-sum
1250-longest-common-subsequence
1402-count-square-submatrices-with-all-ones
1437-minimum-insertion-steps-to-make-a-string-palindrome
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1458-max-dot-product-of-two-subsequences
1511-count-number-of-teams
1586-longest-subarray-of-1s-after-deleting-one-element
1669-minimum-cost-to-cut-a-stick
1756-minimum-deletions-to-make-string-balanced
2067-maximum-number-of-points-with-cost
2554-minimum-total-distance-traveled
2586-longest-square-streak-in-an-array
3640-trionic-array-ii

Recursion

Problem Name	Difficulty
0044-wildcard-matching
0224-basic-calculator
0234-palindrome-linked-list
0241-different-ways-to-add-parentheses
0273-integer-to-english-words
1197-parsing-a-boolean-expression
1667-find-kth-bit-in-nth-binary-string
1951-find-the-winner-of-the-circular-game

Queue

Problem Name	Difficulty
0859-design-circular-deque
1951-find-the-winner-of-the-circular-game

Stack

Problem Name	Difficulty
0145-binary-tree-postorder-traversal
0224-basic-calculator
0234-palindrome-linked-list
0726-number-of-atoms
0957-minimum-add-to-make-parentheses-valid
1197-parsing-a-boolean-expression
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1720-crawler-log-folder
1756-minimum-deletions-to-make-string-balanced
2095-minimum-number-of-swaps-to-make-the-string-balanced

Binary Search

Problem Name	Difficulty
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0081-search-in-rotated-sorted-array-ii
0222-count-complete-tree-nodes
0540-single-element-in-a-sorted-array
0719-find-k-th-smallest-pair-distance
0729-my-calendar-i
0731-my-calendar-ii
0732-my-calendar-iii
1046-max-consecutive-ones-iii
1468-check-if-n-and-its-double-exist
1615-range-sum-of-sorted-subarray-sums
1646-kth-missing-positive-number
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1753-path-with-minimum-effort
1977-minimum-interval-to-include-each-query
2006-find-the-student-that-will-replace-the-chalk
2586-longest-square-streak-in-an-array
2699-count-the-number-of-fair-pairs
2716-prime-subtraction-operation
3453-separate-squares-i

Tree

Problem Name	Difficulty
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0110-balanced-binary-tree
0124-binary-tree-maximum-path-sum
0145-binary-tree-postorder-traversal
0222-count-complete-tree-nodes
0236-lowest-common-ancestor-of-a-binary-tree
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0789-kth-largest-element-in-a-stream
0893-all-nodes-distance-k-in-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1207-delete-nodes-and-return-forest
1484-linked-list-in-binary-tree
2461-amount-of-time-for-binary-tree-to-be-infected

Binary Tree

Problem Name	Difficulty
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0110-balanced-binary-tree
0124-binary-tree-maximum-path-sum
0145-binary-tree-postorder-traversal
0222-count-complete-tree-nodes
0236-lowest-common-ancestor-of-a-binary-tree
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0789-kth-largest-element-in-a-stream
0893-all-nodes-distance-k-in-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1207-delete-nodes-and-return-forest
1484-linked-list-in-binary-tree
2461-amount-of-time-for-binary-tree-to-be-infected

Shortest Path

Problem Name	Difficulty
1325-path-with-maximum-probability
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
2171-second-minimum-time-to-reach-destination
2678-design-graph-with-shortest-path-calculator

Binary Indexed Tree

Problem Name	Difficulty
1511-count-number-of-teams

Two Pointers

Problem Name	Difficulty
0005-longest-palindromic-substring
0028-find-the-index-of-the-first-occurrence-in-a-string
0234-palindrome-linked-list
0455-assign-cookies
0567-permutation-in-string
0719-find-k-th-smallest-pair-distance
1468-check-if-n-and-its-double-exist
1615-range-sum-of-sorted-subarray-sums
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1972-rotating-the-box
2095-minimum-number-of-swaps-to-make-the-string-balanced
2414-move-pieces-to-obtain-a-string
2488-divide-intervals-into-minimum-number-of-groups
2699-count-the-number-of-fair-pairs
3195-separate-black-and-white-balls

Backtracking

Problem Name	Difficulty
0494-target-sum
1715-split-a-string-into-the-max-number-of-unique-substrings

Matrix

Problem Name	Difficulty
0073-set-matrix-zeroes
1171-shortest-path-in-binary-matrix
1402-count-square-submatrices-with-all-ones
1691-minimum-number-of-days-to-disconnect-island
1753-path-with-minimum-effort
1895-largest-magic-square
1972-rotating-the-box
2035-count-sub-islands
2343-count-unguarded-cells-in-the-grid

Strongly Connected Component

Problem Name	Difficulty
1691-minimum-number-of-days-to-disconnect-island

Design

Problem Name	Difficulty
0715-range-module
0729-my-calendar-i
0731-my-calendar-ii
0732-my-calendar-iii
0789-kth-largest-element-in-a-stream
0859-design-circular-deque
2357-count-integers-in-intervals
2678-design-graph-with-shortest-path-calculator

Binary Search Tree

Problem Name	Difficulty
0789-kth-largest-element-in-a-stream

Heap (Priority Queue)

Problem Name	Difficulty
0632-smallest-range-covering-elements-from-k-lists
0789-kth-largest-element-in-a-stream
1325-path-with-maximum-probability
1753-path-with-minimum-effort
1977-minimum-interval-to-include-each-query
2054-the-number-of-the-smallest-unoccupied-chair
2488-divide-intervals-into-minimum-number-of-groups
2616-maximal-score-after-applying-k-operations
2678-design-graph-with-shortest-path-calculator
2692-take-gifts-from-the-richest-pile

Data Stream

Problem Name	Difficulty
0789-kth-largest-element-in-a-stream

Database

Problem Name	Difficulty
0176-second-highest-salary
0180-consecutive-numbers
0185-department-top-three-salaries
0197-rising-temperature
0570-managers-with-at-least-5-direct-reports
0584-find-customer-referee
0585-investments-in-2016
0595-big-countries
0602-friend-requests-ii-who-has-the-most-friends
0610-triangle-judgement
0619-biggest-single-number
0626-exchange-seats
1153-product-sales-analysis-i
1161-project-employees-i
1245-user-activity-for-the-past-30-days-i
1258-article-views-i
1278-product-price-at-a-given-date
1292-immediate-food-delivery-ii
1338-queries-quality-and-percentage
1390-average-selling-price
1415-students-and-examinations
1452-restaurant-growth
1462-list-the-products-ordered-in-a-period
1480-movie-rating
1625-group-sold-products-by-the-date
1724-customer-who-visited-but-did-not-make-any-transactions
1773-percentage-of-users-attended-a-contest
1827-invalid-tweets
1877-find-followers-count
1882-the-number-of-employees-which-report-to-each-employee
1908-recyclable-and-low-fat-products
1942-primary-department-for-each-employee
2057-count-salary-categories

Bit Manipulation

Problem Name	Difficulty
0222-count-complete-tree-nodes
0476-number-complement
0762-prime-number-of-set-bits-in-binary-representation
1473-find-the-longest-substring-containing-vowels-in-even-counts
2503-longest-subarray-with-maximum-bitwise-and

Divide and Conquer

Problem Name	Difficulty
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0761-special-binary-string

Brainteaser

Problem Name	Difficulty
2503-longest-subarray-with-maximum-bitwise-and

Memoization

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

Rolling Hash

Problem Name	Difficulty
0214-shortest-palindrome
1508-longest-happy-prefix

String Matching

Problem Name	Difficulty
0028-find-the-index-of-the-first-occurrence-in-a-string
0214-shortest-palindrome
1508-longest-happy-prefix

Hash Function

Problem Name	Difficulty
0214-shortest-palindrome
1508-longest-happy-prefix

Trie

Problem Name	Difficulty
0014-longest-common-prefix
0386-lexicographical-numbers
0440-k-th-smallest-in-lexicographical-order
1350-remove-sub-folders-from-the-filesystem
3329-find-the-length-of-the-longest-common-prefix

Segment Tree

Problem Name	Difficulty
0715-range-module
0729-my-calendar-i
0731-my-calendar-ii
0732-my-calendar-iii
2357-count-integers-in-intervals

Ordered Set

Problem Name	Difficulty
0715-range-module
0729-my-calendar-i
0731-my-calendar-ii
0732-my-calendar-iii
2357-count-integers-in-intervals

Counting

Problem Name	Difficulty
1620-check-if-array-pairs-are-divisible-by-k
1983-maximum-population-year
3872-find-most-frequent-vowel-and-consonant

Line Sweep

Problem Name	Difficulty
1977-minimum-interval-to-include-each-query

Number Theory

Problem Name	Difficulty
2716-prime-subtraction-operation

Monotonic Stack

Problem Name	Difficulty
1679-shortest-subarray-to-be-removed-to-make-array-sorted

Geometry

Problem Name	Difficulty
1266-minimum-time-visiting-all-points
3278-find-the-number-of-ways-to-place-people-i

Enumeration

Problem Name	Difficulty
3278-find-the-number-of-ways-to-place-people-i