🚀 Coding Practice Repository

A curated collection of important and high-quality coding problems solved from different competitive programming platforms.

This repository is created to strengthen Data Structures & Algorithms, improve problem-solving skills, and maintain a well-organized reference for future revision and interviews.

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📌 Platforms Covered

• ✅ LeetCode (LC)
• ✅ Codeforces (CF)
• ✅ GeeksforGeeks (GFG)

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🧠 What You’ll Find Here

• 📘 Hand-picked good-quality problems
• 🧩 Problems ranging from easy → medium → hard
• ⚡ Optimized and clean solutions
• 🧠 Logical explanations where required
• 🎯 Frequently asked interview problems
• 🏆 Competitive programming standard approaches

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✨ Topics Covered

• Arrays & Strings
• Two Pointers
• Sliding Window
• Prefix Sum
• Hashing
• Recursion & Backtracking
• Linked List
• Stack & Queue
• Binary Search
• Trees & BST
• Graphs (BFS / DFS / Shortest Path)
• Dynamic Programming
• Greedy Algorithms
• Bit Manipulation

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📈 Purpose of This Repository

• 🔹 Daily DSA practice
• 🔹 Interview preparation
• 🔹 Competitive programming improvement
• 🔹 Revision before contests
• 🔹 Maintain clean solution archive

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🌟 Highlights

• ✅ Clean and readable code
• ✅ Optimized solutions
• ✅ Covers real interview patterns
• ✅ Regularly updated
• ✅ Beginner to advanced friendly

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📊 Platforms Profile

• LeetCode – DSA & Interview focused
• Codeforces – Competitive logic & speed
• GeeksforGeeks – Core concept strengthening

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🚀 How to Use

1. Clone the repository:

   git clone https://github.com/premmsharma122/coding-plateform-question.git
   
   

LeetCode Topics

Divide and Conquer

0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0190-reverse-bits
0347-top-k-frequent-elements
0761-special-binary-string
1382-balance-a-binary-search-tree
3653-xor-after-range-multiplication-queries-i
3655-xor-after-range-multiplication-queries-ii
3719-longest-balanced-subarray-i
3721-longest-balanced-subarray-ii
3737-count-subarrays-with-majority-element-i
3739-count-subarrays-with-majority-element-ii

Greedy

0316-remove-duplicate-letters
0826-most-profit-assigning-work
1081-smallest-subsequence-of-distinct-characters
1217-minimum-cost-to-move-chips-to-the-same-position
1382-balance-a-binary-search-tree
1536-minimum-swaps-to-arrange-a-binary-grid
1665-minimum-initial-energy-to-finish-tasks
1689-partitioning-into-minimum-number-of-deci-binary-numbers
1727-largest-submatrix-with-rearrangements
1802-maximum-value-at-a-given-index-in-a-bounded-array
1833-maximum-ice-cream-bars
1846-maximum-element-after-decreasing-and-rearranging
1962-remove-stones-to-minimize-the-total
2064-minimized-maximum-of-products-distributed-to-any-store
2078-two-furthest-houses-with-different-colors
2126-destroying-asteroids
2144-minimum-cost-of-buying-candies-with-discount
2439-minimize-maximum-of-array
2448-minimum-cost-to-make-array-equal
2560-house-robber-iv
2573-find-the-string-with-lcp
2616-minimize-the-maximum-difference-of-pairs
2673-make-costs-of-paths-equal-in-a-binary-tree
3014-minimum-number-of-pushes-to-type-word-i
3296-minimum-number-of-seconds-to-make-mountain-height-zero
3348-smallest-divisible-digit-product-ii
3474-lexicographically-smallest-generated-string
3534-path-existence-queries-in-a-graph-ii
3600-maximize-spanning-tree-stability-with-upgrades
3633-earliest-finish-time-for-land-and-water-rides-i
3635-earliest-finish-time-for-land-and-water-rides-ii
3689-maximum-total-subarray-value-i
3691-maximum-total-subarray-value-ii

Tree

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0124-binary-tree-maximum-path-sum
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0236-lowest-common-ancestor-of-a-binary-tree
0257-binary-tree-paths
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0700-search-in-a-binary-search-tree
0987-vertical-order-traversal-of-a-binary-tree
1022-sum-of-root-to-leaf-binary-numbers
1325-delete-leaves-with-a-given-value
1382-balance-a-binary-search-tree
1483-kth-ancestor-of-a-tree-node
1609-even-odd-tree
2196-create-binary-tree-from-descriptions
2476-closest-nodes-queries-in-a-binary-search-tree
2673-make-costs-of-paths-equal-in-a-binary-tree
3203-find-minimum-diameter-after-merging-two-trees
3558-number-of-ways-to-assign-edge-weights-i
3559-number-of-ways-to-assign-edge-weights-ii

Depth-First Search

0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0124-binary-tree-maximum-path-sum
0133-clone-graph
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0236-lowest-common-ancestor-of-a-binary-tree
0257-binary-tree-paths
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0743-network-delay-time
0987-vertical-order-traversal-of-a-binary-tree
1022-sum-of-root-to-leaf-binary-numbers
1306-jump-game-iii
1319-number-of-operations-to-make-network-connected
1325-delete-leaves-with-a-given-value
1382-balance-a-binary-search-tree
1391-check-if-there-is-a-valid-path-in-a-grid
1483-kth-ancestor-of-a-tree-node
1559-detect-cycles-in-2d-grid
1631-path-with-minimum-effort
1722-minimize-hamming-distance-after-swap-operations
2097-valid-arrangement-of-pairs
2316-count-unreachable-pairs-of-nodes-in-an-undirected-graph
2476-closest-nodes-queries-in-a-binary-search-tree
2492-minimum-score-of-a-path-between-two-cities
2685-count-the-number-of-complete-components
3203-find-minimum-diameter-after-merging-two-trees
3310-remove-methods-from-project
3558-number-of-ways-to-assign-edge-weights-i
3559-number-of-ways-to-assign-edge-weights-ii

Binary Search Tree

0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0074-search-a-2d-matrix
0108-convert-sorted-array-to-binary-search-tree
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0222-count-complete-tree-nodes
0300-longest-increasing-subsequence
0540-single-element-in-a-sorted-array
0700-search-in-a-binary-search-tree
0719-find-k-th-smallest-pair-distance
0826-most-profit-assigning-work
0887-super-egg-drop
0902-numbers-at-most-n-given-digit-set
1011-capacity-to-ship-packages-within-d-days
1235-maximum-profit-in-job-scheduling
1382-balance-a-binary-search-tree
1482-minimum-number-of-days-to-make-m-bouquets
1483-kth-ancestor-of-a-tree-node
1539-kth-missing-positive-number
1552-magnetic-force-between-two-balls
1608-special-array-with-x-elements-greater-than-or-equal-x
1631-path-with-minimum-effort
1760-minimum-limit-of-balls-in-a-bag
1802-maximum-value-at-a-given-index-in-a-bounded-array
1855-maximum-distance-between-a-pair-of-values
1870-minimum-speed-to-arrive-on-time
2064-minimized-maximum-of-products-distributed-to-any-store
2070-most-beautiful-item-for-each-query
2187-minimum-time-to-complete-trips
2226-maximum-candies-allocated-to-k-children
2251-number-of-flowers-in-full-bloom
2439-minimize-maximum-of-array
2448-minimum-cost-to-make-array-equal
2476-closest-nodes-queries-in-a-binary-search-tree
2540-minimum-common-value
2560-house-robber-iv
2563-count-the-number-of-fair-pairs
2594-minimum-time-to-repair-cars
2616-minimize-the-maximum-difference-of-pairs
2812-find-the-safest-path-in-a-grid
2968-apply-operations-to-maximize-frequency-score
3161-block-placement-queries
3296-minimum-number-of-seconds-to-make-mountain-height-zero
3312-sorted-gcd-pair-queries
3356-zero-array-transformation-ii
3464-maximize-the-distance-between-points-on-a-square
3488-closest-equal-element-queries
3501-maximize-active-section-with-trade-ii
3532-path-existence-queries-in-a-graph-i
3534-path-existence-queries-in-a-graph-ii
3600-maximize-spanning-tree-stability-with-upgrades
3633-earliest-finish-time-for-land-and-water-rides-i
3635-earliest-finish-time-for-land-and-water-rides-ii

Binary Tree

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0124-binary-tree-maximum-path-sum
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0236-lowest-common-ancestor-of-a-binary-tree
0257-binary-tree-paths
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0700-search-in-a-binary-search-tree
0987-vertical-order-traversal-of-a-binary-tree
1022-sum-of-root-to-leaf-binary-numbers
1325-delete-leaves-with-a-given-value
1382-balance-a-binary-search-tree
1609-even-odd-tree
2196-create-binary-tree-from-descriptions
2476-closest-nodes-queries-in-a-binary-search-tree
2673-make-costs-of-paths-equal-in-a-binary-tree

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0116-populating-next-right-pointers-in-each-node
0133-clone-graph
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0279-perfect-squares
0322-coin-change
0662-maximum-width-of-binary-tree
0743-network-delay-time
0987-vertical-order-traversal-of-a-binary-tree
1091-shortest-path-in-binary-matrix
1306-jump-game-iii
1319-number-of-operations-to-make-network-connected
1345-jump-game-iv
1391-check-if-there-is-a-valid-path-in-a-grid
1483-kth-ancestor-of-a-tree-node
1559-detect-cycles-in-2d-grid
1609-even-odd-tree
1631-path-with-minimum-effort
1765-map-of-highest-peak
2316-count-unreachable-pairs-of-nodes-in-an-undirected-graph
2492-minimum-score-of-a-path-between-two-cities
2685-count-the-number-of-complete-components
2812-find-the-safest-path-in-a-grid
3203-find-minimum-diameter-after-merging-two-trees
3286-find-a-safe-walk-through-a-grid
3310-remove-methods-from-project
3629-minimum-jumps-to-reach-end-via-prime-teleportation

Bit Manipulation

0067-add-binary
0190-reverse-bits
0222-count-complete-tree-nodes
0401-binary-watch
0693-binary-number-with-alternating-bits
0762-prime-number-of-set-bits-in-binary-representation
0868-binary-gap
1009-complement-of-base-10-integer
1404-number-of-steps-to-reduce-a-number-in-binary-representation-to-one
1461-check-if-a-string-contains-all-binary-codes-of-size-k
1483-kth-ancestor-of-a-tree-node
1680-concatenation-of-consecutive-binary-numbers
2657-find-the-prefix-common-array-of-two-arrays
3513-number-of-unique-xor-triplets-i
3514-number-of-unique-xor-triplets-ii
3534-path-existence-queries-in-a-graph-ii
3559-number-of-ways-to-assign-edge-weights-ii

Array

0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0048-rotate-image
0064-minimum-path-sum
0074-search-a-2d-matrix
0084-largest-rectangle-in-histogram
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0139-word-break
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0198-house-robber
0200-number-of-islands
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0322-coin-change
0347-top-k-frequent-elements
0396-rotate-function
0416-partition-equal-subset-sum
0494-target-sum
0540-single-element-in-a-sorted-array
0628-maximum-product-of-three-numbers
0719-find-k-th-smallest-pair-distance
0826-most-profit-assigning-work
0874-walking-robot-simulation
0877-stone-game
0902-numbers-at-most-n-given-digit-set
0990-satisfiability-of-equality-equations
1011-capacity-to-ship-packages-within-d-days
1046-last-stone-weight
1091-shortest-path-in-binary-matrix
1140-stone-game-ii
1186-maximum-subarray-sum-with-one-deletion
1217-minimum-cost-to-move-chips-to-the-same-position
1235-maximum-profit-in-job-scheduling
1260-shift-2d-grid
1288-remove-covered-intervals
1301-number-of-paths-with-max-score
1306-jump-game-iii
1331-rank-transform-of-an-array
1340-jump-game-v
1345-jump-game-iv
1391-check-if-there-is-a-valid-path-in-a-grid
1406-stone-game-iii
1464-maximum-product-of-two-elements-in-an-array
1482-minimum-number-of-days-to-make-m-bouquets
1536-minimum-swaps-to-arrange-a-binary-grid
1539-kth-missing-positive-number
1552-magnetic-force-between-two-balls
1559-detect-cycles-in-2d-grid
1582-special-positions-in-a-binary-matrix
1584-min-cost-to-connect-all-points
1594-maximum-non-negative-product-in-a-matrix
1608-special-array-with-x-elements-greater-than-or-equal-x
1631-path-with-minimum-effort
1665-minimum-initial-energy-to-finish-tasks
1674-minimum-moves-to-make-array-complementary
1722-minimize-hamming-distance-after-swap-operations
1727-largest-submatrix-with-rearrangements
1732-find-the-highest-altitude
1752-check-if-array-is-sorted-and-rotated
1760-minimum-limit-of-balls-in-a-bag
1765-map-of-highest-peak
1833-maximum-ice-cream-bars
1834-single-threaded-cpu
1846-maximum-element-after-decreasing-and-rearranging
1848-minimum-distance-to-the-target-element
1855-maximum-distance-between-a-pair-of-values
1861-rotating-the-box
1870-minimum-speed-to-arrive-on-time
1878-get-biggest-three-rhombus-sums-in-a-grid
1886-determine-whether-matrix-can-be-obtained-by-rotation
1914-cyclically-rotating-a-grid
1962-remove-stones-to-minimize-the-total
1967-number-of-strings-that-appear-as-substrings-in-word
1979-find-greatest-common-divisor-of-array
1980-find-unique-binary-string
2033-minimum-operations-to-make-a-uni-value-grid
2064-minimized-maximum-of-products-distributed-to-any-store
2070-most-beautiful-item-for-each-query
2078-two-furthest-houses-with-different-colors
2097-valid-arrangement-of-pairs
2126-destroying-asteroids
2144-minimum-cost-of-buying-candies-with-discount
2161-partition-array-according-to-given-pivot
2187-minimum-time-to-complete-trips
2196-create-binary-tree-from-descriptions
2226-maximum-candies-allocated-to-k-children
2251-number-of-flowers-in-full-bloom
2439-minimize-maximum-of-array
2448-minimum-cost-to-make-array-equal
2452-words-within-two-edits-of-dictionary
2463-minimum-total-distance-traveled
2476-closest-nodes-queries-in-a-binary-search-tree
2515-shortest-distance-to-target-string-in-a-circular-array
2540-minimum-common-value
2553-separate-the-digits-in-an-array
2560-house-robber-iv
2563-count-the-number-of-fair-pairs
2573-find-the-string-with-lcp
2574-left-and-right-sum-differences
2594-minimum-time-to-repair-cars
2615-sum-of-distances
2616-minimize-the-maximum-difference-of-pairs
2657-find-the-prefix-common-array-of-two-arrays
2673-make-costs-of-paths-equal-in-a-binary-tree
2751-robot-collisions
2770-maximum-number-of-jumps-to-reach-the-last-index
2784-check-if-array-is-good
2812-find-the-safest-path-in-a-grid
2906-construct-product-matrix
2946-matrix-similarity-after-cyclic-shifts
2968-apply-operations-to-maximize-frequency-score
3020-find-the-maximum-number-of-elements-in-subset
3043-find-the-length-of-the-longest-common-prefix
3070-count-submatrices-with-top-left-element-and-sum-less-than-k
3093-longest-common-suffix-queries
3161-block-placement-queries
3212-count-submatrices-with-equal-frequency-of-x-and-y
3225-maximum-score-from-grid-operations
3286-find-a-safe-walk-through-a-grid
3296-minimum-number-of-seconds-to-make-mountain-height-zero
3300-minimum-element-after-replacement-with-digit-sum
3312-sorted-gcd-pair-queries
3336-find-the-number-of-subsequences-with-equal-gcd
3355-zero-array-transformation-i
3356-zero-array-transformation-ii
3418-maximum-amount-of-money-robot-can-earn
3464-maximize-the-distance-between-points-on-a-square
3488-closest-equal-element-queries
3501-maximize-active-section-with-trade-ii
3513-number-of-unique-xor-triplets-i
3514-number-of-unique-xor-triplets-ii
3532-path-existence-queries-in-a-graph-i
3534-path-existence-queries-in-a-graph-ii
3546-equal-sum-grid-partition-i
3559-number-of-ways-to-assign-edge-weights-ii
3567-minimum-absolute-difference-in-sliding-submatrix
3629-minimum-jumps-to-reach-end-via-prime-teleportation
3633-earliest-finish-time-for-land-and-water-rides-i
3635-earliest-finish-time-for-land-and-water-rides-ii
3643-flip-square-submatrix-vertically
3653-xor-after-range-multiplication-queries-i
3655-xor-after-range-multiplication-queries-ii
3660-jump-game-ix
3689-maximum-total-subarray-value-i
3691-maximum-total-subarray-value-ii
3719-longest-balanced-subarray-i
3721-longest-balanced-subarray-ii
3731-find-missing-elements
3737-count-subarrays-with-majority-element-i
3739-count-subarrays-with-majority-element-ii
3740-minimum-distance-between-three-equal-elements-i
3741-minimum-distance-between-three-equal-elements-ii
3742-maximum-path-score-in-a-grid
3761-minimum-absolute-distance-between-mirror-pairs
3838-weighted-word-mapping
3867-sum-of-gcd-of-formed-pairs

Hash Table

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0133-clone-graph
0139-word-break
0141-linked-list-cycle
0160-intersection-of-two-linked-lists
0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0874-walking-robot-simulation
0987-vertical-order-traversal-of-a-binary-tree
1189-maximum-number-of-balloons
1331-rank-transform-of-an-array
1345-jump-game-iv
1358-number-of-substrings-containing-all-three-characters
1461-check-if-a-string-contains-all-binary-codes-of-size-k
1674-minimum-moves-to-make-array-complementary
1980-find-unique-binary-string
2196-create-binary-tree-from-descriptions
2251-number-of-flowers-in-full-bloom
2540-minimum-common-value
2615-sum-of-distances
2657-find-the-prefix-common-array-of-two-arrays
2784-check-if-array-is-good
2840-check-if-strings-can-be-made-equal-with-operations-ii
2953-count-complete-substrings
3020-find-the-maximum-number-of-elements-in-subset
3043-find-the-length-of-the-longest-common-prefix
3120-count-the-number-of-special-characters-i
3121-count-the-number-of-special-characters-ii
3312-sorted-gcd-pair-queries
3488-closest-equal-element-queries
3518-smallest-palindromic-rearrangement-ii
3532-path-existence-queries-in-a-graph-i
3629-minimum-jumps-to-reach-end-via-prime-teleportation
3713-longest-balanced-substring-i
3714-longest-balanced-substring-ii
3719-longest-balanced-subarray-i
3721-longest-balanced-subarray-ii
3731-find-missing-elements
3737-count-subarrays-with-majority-element-i
3739-count-subarrays-with-majority-element-ii
3740-minimum-distance-between-three-equal-elements-i
3741-minimum-distance-between-three-equal-elements-ii
3761-minimum-absolute-distance-between-mirror-pairs

Segment Tree

1622-fancy-sequence
3161-block-placement-queries
3501-maximize-active-section-with-trade-ii
3691-maximum-total-subarray-value-ii
3719-longest-balanced-subarray-i
3721-longest-balanced-subarray-ii
3737-count-subarrays-with-majority-element-i
3739-count-subarrays-with-majority-element-ii

Prefix Sum

1140-stone-game-ii
1674-minimum-moves-to-make-array-complementary
1732-find-the-highest-altitude
1871-jump-game-vii
1878-get-biggest-three-rhombus-sums-in-a-grid
2251-number-of-flowers-in-full-bloom
2439-minimize-maximum-of-array
2448-minimum-cost-to-make-array-equal
2574-left-and-right-sum-differences
2615-sum-of-distances
2906-construct-product-matrix
2968-apply-operations-to-maximize-frequency-score
3070-count-submatrices-with-top-left-element-and-sum-less-than-k
3129-find-all-possible-stable-binary-arrays-i
3130-find-all-possible-stable-binary-arrays-ii
3212-count-submatrices-with-equal-frequency-of-x-and-y
3225-maximum-score-from-grid-operations
3312-sorted-gcd-pair-queries
3355-zero-array-transformation-i
3356-zero-array-transformation-ii
3546-equal-sum-grid-partition-i
3699-number-of-zigzag-arrays-i
3714-longest-balanced-substring-ii
3719-longest-balanced-subarray-i
3721-longest-balanced-subarray-ii
3737-count-subarrays-with-majority-element-i
3739-count-subarrays-with-majority-element-ii
3756-concatenate-non-zero-digits-and-multiply-by-sum-ii

String

0003-longest-substring-without-repeating-characters
0032-longest-valid-parentheses
0067-add-binary
0072-edit-distance
0076-minimum-window-substring
0091-decode-ways
0131-palindrome-partitioning
0139-word-break
0257-binary-tree-paths
0273-integer-to-english-words
0316-remove-duplicate-letters
0451-sort-characters-by-frequency
0657-robot-return-to-origin
0696-count-binary-substrings
0761-special-binary-string
0796-rotate-string
0902-numbers-at-most-n-given-digit-set
0990-satisfiability-of-equality-equations
1081-smallest-subsequence-of-distinct-characters
1143-longest-common-subsequence
1189-maximum-number-of-balloons
1320-minimum-distance-to-type-a-word-using-two-fingers
1358-number-of-substrings-containing-all-three-characters
1404-number-of-steps-to-reduce-a-number-in-binary-representation-to-one
1415-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1461-check-if-a-string-contains-all-binary-codes-of-size-k
1545-find-kth-bit-in-nth-binary-string
1689-partitioning-into-minimum-number-of-deci-binary-numbers
1758-minimum-changes-to-make-alternating-binary-string
1784-check-if-binary-string-has-at-most-one-segment-of-ones
1871-jump-game-vii
1888-minimum-number-of-flips-to-make-the-binary-string-alternating
1967-number-of-strings-that-appear-as-substrings-in-word
1980-find-unique-binary-string
2075-decode-the-slanted-ciphertext
2452-words-within-two-edits-of-dictionary
2515-shortest-distance-to-target-string-in-a-circular-array
2573-find-the-string-with-lcp
2719-count-of-integers
2833-furthest-point-from-origin
2839-check-if-strings-can-be-made-equal-with-operations-i
2840-check-if-strings-can-be-made-equal-with-operations-ii
2953-count-complete-substrings
3014-minimum-number-of-pushes-to-type-word-i
3043-find-the-length-of-the-longest-common-prefix
3093-longest-common-suffix-queries
3120-count-the-number-of-special-characters-i
3121-count-the-number-of-special-characters-ii
3348-smallest-divisible-digit-product-ii
3474-lexicographically-smallest-generated-string
3499-maximize-active-section-with-trade-i
3501-maximize-active-section-with-trade-ii
3517-smallest-palindromic-rearrangement-i
3518-smallest-palindromic-rearrangement-ii
3612-process-string-with-special-operations-i
3614-process-string-with-special-operations-ii
3713-longest-balanced-substring-i
3714-longest-balanced-substring-ii
3756-concatenate-non-zero-digits-and-multiply-by-sum-ii
3838-weighted-word-mapping

Counting

0347-top-k-frequent-elements
0451-sort-characters-by-frequency
1189-maximum-number-of-balloons
2833-furthest-point-from-origin
3312-sorted-gcd-pair-queries
3518-smallest-palindromic-rearrangement-ii
3713-longest-balanced-substring-i
3737-count-subarrays-with-majority-element-i

Enumeration

1291-sequential-digits
3020-find-the-maximum-number-of-elements-in-subset
3345-smallest-divisible-digit-product-i
3499-maximize-active-section-with-trade-i
3514-number-of-unique-xor-triplets-ii
3546-equal-sum-grid-partition-i
3713-longest-balanced-substring-i
3751-total-waviness-of-numbers-in-range-i

Dynamic Programming

0032-longest-valid-parentheses
0064-minimum-path-sum
0072-edit-distance
0091-decode-ways
0124-binary-tree-maximum-path-sum
0131-palindrome-partitioning
0139-word-break
0152-maximum-product-subarray
0198-house-robber
0233-number-of-digit-one
0279-perfect-squares
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0322-coin-change
0396-rotate-function
0416-partition-equal-subset-sum
0494-target-sum
0509-fibonacci-number
0600-non-negative-integers-without-consecutive-ones
0788-rotated-digits
0799-champagne-tower
0877-stone-game
0887-super-egg-drop
0902-numbers-at-most-n-given-digit-set
1140-stone-game-ii
1143-longest-common-subsequence
1186-maximum-subarray-sum-with-one-deletion
1235-maximum-profit-in-job-scheduling
1301-number-of-paths-with-max-score
1320-minimum-distance-to-type-a-word-using-two-fingers
1340-jump-game-v
1406-stone-game-iii
1483-kth-ancestor-of-a-tree-node
1594-maximum-non-negative-product-in-a-matrix
1871-jump-game-vii
1888-minimum-number-of-flips-to-make-the-binary-string-alternating
2439-minimize-maximum-of-array
2463-minimum-total-distance-traveled
2560-house-robber-iv
2573-find-the-string-with-lcp
2616-minimize-the-maximum-difference-of-pairs
2673-make-costs-of-paths-equal-in-a-binary-tree
2719-count-of-integers
2770-maximum-number-of-jumps-to-reach-the-last-index
3129-find-all-possible-stable-binary-arrays-i
3130-find-all-possible-stable-binary-arrays-ii
3225-maximum-score-from-grid-operations
3336-find-the-number-of-subsequences-with-equal-gcd
3418-maximum-amount-of-money-robot-can-earn
3534-path-existence-queries-in-a-graph-ii
3559-number-of-ways-to-assign-edge-weights-ii
3660-jump-game-ix
3699-number-of-zigzag-arrays-i
3700-number-of-zigzag-arrays-ii
3742-maximum-path-score-in-a-grid
3751-total-waviness-of-numbers-in-range-i
3753-total-waviness-of-numbers-in-range-ii

Math

0002-add-two-numbers
0048-rotate-image
0067-add-binary
0233-number-of-digit-one
0273-integer-to-english-words
0279-perfect-squares
0396-rotate-function
0509-fibonacci-number
0628-maximum-product-of-three-numbers
0762-prime-number-of-set-bits-in-binary-representation
0788-rotated-digits
0877-stone-game
0887-super-egg-drop
0902-numbers-at-most-n-given-digit-set
1140-stone-game-ii
1217-minimum-cost-to-move-chips-to-the-same-position
1406-stone-game-iii
1622-fancy-sequence
1680-concatenation-of-consecutive-binary-numbers
1802-maximum-value-at-a-given-index-in-a-bounded-array
1878-get-biggest-three-rhombus-sums-in-a-grid
1979-find-greatest-common-divisor-of-array
2033-minimum-operations-to-make-a-uni-value-grid
2719-count-of-integers
2946-matrix-similarity-after-cyclic-shifts
3014-minimum-number-of-pushes-to-type-word-i
3296-minimum-number-of-seconds-to-make-mountain-height-zero
3300-minimum-element-after-replacement-with-digit-sum
3312-sorted-gcd-pair-queries
3336-find-the-number-of-subsequences-with-equal-gcd
3345-smallest-divisible-digit-product-i
3348-smallest-divisible-digit-product-ii
3464-maximize-the-distance-between-points-on-a-square
3513-number-of-unique-xor-triplets-i
3514-number-of-unique-xor-triplets-ii
3518-smallest-palindromic-rearrangement-ii
3536-maximum-product-of-two-digits
3558-number-of-ways-to-assign-edge-weights-i
3559-number-of-ways-to-assign-edge-weights-ii
3629-minimum-jumps-to-reach-end-via-prime-teleportation
3658-gcd-of-odd-and-even-sums
3700-number-of-zigzag-arrays-ii
3751-total-waviness-of-numbers-in-range-i
3753-total-waviness-of-numbers-in-range-ii
3754-concatenate-non-zero-digits-and-multiply-by-sum-i
3756-concatenate-non-zero-digits-and-multiply-by-sum-ii
3761-minimum-absolute-distance-between-mirror-pairs
3783-mirror-distance-of-an-integer
3867-sum-of-gcd-of-formed-pairs

Simulation

0067-add-binary
0657-robot-return-to-origin
0874-walking-robot-simulation
1260-shift-2d-grid
1404-number-of-steps-to-reduce-a-number-in-binary-representation-to-one
1545-find-kth-bit-in-nth-binary-string
1680-concatenation-of-consecutive-binary-numbers
1914-cyclically-rotating-a-grid
2069-walking-robot-simulation-ii
2075-decode-the-slanted-ciphertext
2161-partition-array-according-to-given-pivot
2553-separate-the-digits-in-an-array
2751-robot-collisions
2946-matrix-similarity-after-cyclic-shifts
3612-process-string-with-special-operations-i
3614-process-string-with-special-operations-ii
3653-xor-after-range-multiplication-queries-i
3838-weighted-word-mapping
3867-sum-of-gcd-of-formed-pairs

Backtracking

0131-palindrome-partitioning
0257-binary-tree-paths
0401-binary-watch
0494-target-sum
1415-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1980-find-unique-binary-string
3348-smallest-divisible-digit-product-ii

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0061-rotate-list
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0141-linked-list-cycle
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0237-delete-node-in-a-linked-list
0876-middle-of-the-linked-list
2095-delete-the-middle-node-of-a-linked-list
2130-maximum-twin-sum-of-a-linked-list

Two Pointers

0019-remove-nth-node-from-end-of-list
0061-rotate-list
0141-linked-list-cycle
0160-intersection-of-two-linked-lists
0696-count-binary-substrings
0719-find-k-th-smallest-pair-distance
0826-most-profit-assigning-work
0876-middle-of-the-linked-list
1855-maximum-distance-between-a-pair-of-values
1861-rotating-the-box
2095-delete-the-middle-node-of-a-linked-list
2130-maximum-twin-sum-of-a-linked-list
2161-partition-array-according-to-given-pivot
2540-minimum-common-value
2563-count-the-number-of-fair-pairs
3356-zero-array-transformation-ii
3534-path-existence-queries-in-a-graph-ii
3633-earliest-finish-time-for-land-and-water-rides-i
3635-earliest-finish-time-for-land-and-water-rides-ii
3643-flip-square-submatrix-vertically
3867-sum-of-gcd-of-formed-pairs

Sorting

0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0628-maximum-product-of-three-numbers
0719-find-k-th-smallest-pair-distance
0761-special-binary-string
0826-most-profit-assigning-work
0987-vertical-order-traversal-of-a-binary-tree
1235-maximum-profit-in-job-scheduling
1288-remove-covered-intervals
1331-rank-transform-of-an-array
1340-jump-game-v
1464-maximum-product-of-two-elements-in-an-array
1552-magnetic-force-between-two-balls
1608-special-array-with-x-elements-greater-than-or-equal-x
1665-minimum-initial-energy-to-finish-tasks
1727-largest-submatrix-with-rearrangements
1833-maximum-ice-cream-bars
1834-single-threaded-cpu
1846-maximum-element-after-decreasing-and-rearranging
1878-get-biggest-three-rhombus-sums-in-a-grid
2033-minimum-operations-to-make-a-uni-value-grid
2070-most-beautiful-item-for-each-query
2126-destroying-asteroids
2144-minimum-cost-of-buying-candies-with-discount
2251-number-of-flowers-in-full-bloom
2448-minimum-cost-to-make-array-equal
2463-minimum-total-distance-traveled
2563-count-the-number-of-fair-pairs
2616-minimize-the-maximum-difference-of-pairs
2751-robot-collisions
2784-check-if-array-is-good
2840-check-if-strings-can-be-made-equal-with-operations-ii
2968-apply-operations-to-maximize-frequency-score
3464-maximize-the-distance-between-points-on-a-square
3517-smallest-palindromic-rearrangement-i
3534-path-existence-queries-in-a-graph-ii
3536-maximum-product-of-two-digits
3567-minimum-absolute-difference-in-sliding-submatrix
3633-earliest-finish-time-for-land-and-water-rides-i
3635-earliest-finish-time-for-land-and-water-rides-ii
3731-find-missing-elements
3867-sum-of-gcd-of-formed-pairs

Rolling Hash

1461-check-if-a-string-contains-all-binary-codes-of-size-k

Hash Function

1461-check-if-a-string-contains-all-binary-codes-of-size-k

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
1358-number-of-substrings-containing-all-three-characters
1871-jump-game-vii
1888-minimum-number-of-flips-to-make-the-binary-string-alternating
2953-count-complete-substrings
2968-apply-operations-to-maximize-frequency-score

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0206-reverse-linked-list
0233-number-of-digit-one
0273-integer-to-english-words
0509-fibonacci-number
1545-find-kth-bit-in-nth-binary-string

Matrix

0048-rotate-image
0064-minimum-path-sum
0074-search-a-2d-matrix
0200-number-of-islands
1091-shortest-path-in-binary-matrix
1260-shift-2d-grid
1301-number-of-paths-with-max-score
1391-check-if-there-is-a-valid-path-in-a-grid
1536-minimum-swaps-to-arrange-a-binary-grid
1559-detect-cycles-in-2d-grid
1582-special-positions-in-a-binary-matrix
1594-maximum-non-negative-product-in-a-matrix
1631-path-with-minimum-effort
1727-largest-submatrix-with-rearrangements
1765-map-of-highest-peak
1861-rotating-the-box
1878-get-biggest-three-rhombus-sums-in-a-grid
1886-determine-whether-matrix-can-be-obtained-by-rotation
1914-cyclically-rotating-a-grid
2033-minimum-operations-to-make-a-uni-value-grid
2573-find-the-string-with-lcp
2812-find-the-safest-path-in-a-grid
2906-construct-product-matrix
2946-matrix-similarity-after-cyclic-shifts
3070-count-submatrices-with-top-left-element-and-sum-less-than-k
3212-count-submatrices-with-equal-frequency-of-x-and-y
3225-maximum-score-from-grid-operations
3286-find-a-safe-walk-through-a-grid
3418-maximum-amount-of-money-robot-can-earn
3546-equal-sum-grid-partition-i
3567-minimum-absolute-difference-in-sliding-submatrix
3643-flip-square-submatrix-vertically
3742-maximum-path-score-in-a-grid

Trie

0139-word-break
2452-words-within-two-edits-of-dictionary
3043-find-the-length-of-the-longest-common-prefix
3093-longest-common-suffix-queries

Memoization

0139-word-break
0509-fibonacci-number

Union-Find

0200-number-of-islands
0990-satisfiability-of-equality-equations
1319-number-of-operations-to-make-network-connected
1391-check-if-there-is-a-valid-path-in-a-grid
1559-detect-cycles-in-2d-grid
1584-min-cost-to-connect-all-points
1631-path-with-minimum-effort
1722-minimize-hamming-distance-after-swap-operations
2316-count-unreachable-pairs-of-nodes-in-an-undirected-graph
2492-minimum-score-of-a-path-between-two-cities
2573-find-the-string-with-lcp
2685-count-the-number-of-complete-components
2812-find-the-safest-path-in-a-grid
3532-path-existence-queries-in-a-graph-i
3600-maximize-spanning-tree-stability-with-upgrades

Graph Theory

0133-clone-graph
0207-course-schedule
0210-course-schedule-ii
0743-network-delay-time
0990-satisfiability-of-equality-equations
1319-number-of-operations-to-make-network-connected
1584-min-cost-to-connect-all-points
2097-valid-arrangement-of-pairs
2316-count-unreachable-pairs-of-nodes-in-an-undirected-graph
2492-minimum-score-of-a-path-between-two-cities
2685-count-the-number-of-complete-components
3203-find-minimum-diameter-after-merging-two-trees
3286-find-a-safe-walk-through-a-grid
3310-remove-methods-from-project
3532-path-existence-queries-in-a-graph-i
3534-path-existence-queries-in-a-graph-ii
3600-maximize-spanning-tree-stability-with-upgrades

Minimum Spanning Tree

1584-min-cost-to-connect-all-points
3600-maximize-spanning-tree-stability-with-upgrades

Heap (Priority Queue)

0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0743-network-delay-time
1046-last-stone-weight
1464-maximum-product-of-two-elements-in-an-array
1631-path-with-minimum-effort
1834-single-threaded-cpu
1878-get-biggest-three-rhombus-sums-in-a-grid
1962-remove-stones-to-minimize-the-total
2812-find-the-safest-path-in-a-grid
3286-find-a-safe-walk-through-a-grid
3296-minimum-number-of-seconds-to-make-mountain-height-zero
3691-maximum-total-subarray-value-ii

Stack

0032-longest-valid-parentheses
0084-largest-rectangle-in-histogram
0114-flatten-binary-tree-to-linked-list
0316-remove-duplicate-letters
1081-smallest-subsequence-of-distinct-characters
2130-maximum-twin-sum-of-a-linked-list
2751-robot-collisions

Design

1483-kth-ancestor-of-a-tree-node
1622-fancy-sequence
2069-walking-robot-simulation-ii

Topological Sort

0207-course-schedule
0210-course-schedule-ii

String Matching

0796-rotate-string
3474-lexicographically-smallest-generated-string

Geometry

3464-maximize-the-distance-between-points-on-a-square

Number Theory

1979-find-greatest-common-divisor-of-array
3312-sorted-gcd-pair-queries
3336-find-the-number-of-subsequences-with-equal-gcd
3348-smallest-divisible-digit-product-ii
3629-minimum-jumps-to-reach-end-via-prime-teleportation
3658-gcd-of-odd-and-even-sums
3867-sum-of-gcd-of-formed-pairs

Monotonic Stack

0084-largest-rectangle-in-histogram
0316-remove-duplicate-letters
1081-smallest-subsequence-of-distinct-characters

Shortest Path

0743-network-delay-time
3286-find-a-safe-walk-through-a-grid

Binary Indexed Tree

3161-block-placement-queries

Eulerian Circuit

2097-valid-arrangement-of-pairs

Database

0176-second-highest-salary
0180-consecutive-numbers
0185-department-top-three-salaries
0196-delete-duplicate-emails
0197-rising-temperature
0550-game-play-analysis-iv
0570-managers-with-at-least-5-direct-reports
0577-employee-bonus
0584-find-customer-referee
0585-investments-in-2016
0595-big-countries
0596-classes-with-at-least-5-students
0602-friend-requests-ii-who-has-the-most-friends
0619-biggest-single-number
0620-not-boring-movies
0626-exchange-seats
1045-customers-who-bought-all-products
1068-product-sales-analysis-i
1070-product-sales-analysis-iii
1075-project-employees-i
1141-user-activity-for-the-past-30-days-i
1148-article-views-i
1164-product-price-at-a-given-date
1174-immediate-food-delivery-ii
1193-monthly-transactions-i
1204-last-person-to-fit-in-the-bus
1211-queries-quality-and-percentage
1251-average-selling-price
1280-students-and-examinations
1341-movie-rating
1378-replace-employee-id-with-the-unique-identifier
1484-group-sold-products-by-the-date
1517-find-users-with-valid-e-mails
1527-patients-with-a-condition
1581-customer-who-visited-but-did-not-make-any-transactions
1633-percentage-of-users-attended-a-contest
1661-average-time-of-process-per-machine
1667-fix-names-in-a-table
1683-invalid-tweets
1729-find-followers-count
1757-recyclable-and-low-fat-products
1789-primary-department-for-each-employee
1907-count-salary-categories
1934-confirmation-rate
1978-employees-whose-manager-left-the-company
2356-number-of-unique-subjects-taught-by-each-teacher

Counting Sort

1833-maximum-ice-cream-bars
3517-smallest-palindromic-rearrangement-i

Merge Sort

3737-count-subarrays-with-majority-element-i
3739-count-subarrays-with-majority-element-ii

Ordered Set

2251-number-of-flowers-in-full-bloom

Combinatorics

3312-sorted-gcd-pair-queries
3518-smallest-palindromic-rearrangement-ii

Bucket Sort

0347-top-k-frequent-elements
0451-sort-characters-by-frequency

Quickselect

0347-top-k-frequent-elements

Game Theory

0877-stone-game
1140-stone-game-ii
1406-stone-game-iii

Minimax

1140-stone-game-ii
1406-stone-game-iii

Zero-Sum Game

1140-stone-game-ii
1406-stone-game-iii