DSA-Problems

A collection of LeetCode(may include other platforms as well) questions to ace the coding interview!

LeetCode Topics

Linked List

0025-reverse-nodes-in-k-group
0061-rotate-list
0083-remove-duplicates-from-sorted-list
0114-flatten-binary-tree-to-linked-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0622-design-circular-queue
0725-split-linked-list-in-parts
0876-middle-of-the-linked-list
3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii

Two Pointers

0015-3sum
0016-3sum-closest
0018-4sum
0031-next-permutation
0042-trapping-rain-water
0061-rotate-list
0075-sort-colors
0141-linked-list-cycle
0142-linked-list-cycle-ii
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0202-happy-number
0283-move-zeroes
0567-permutation-in-string
0581-shortest-unsorted-continuous-subarray
0844-backspace-string-compare
0876-middle-of-the-linked-list
0905-sort-array-by-parity
0977-squares-of-a-sorted-array
1877-minimize-maximum-pair-sum-in-array
2149-rearrange-array-elements-by-sign

Recursion

0025-reverse-nodes-in-k-group
1823-find-the-winner-of-the-circular-game

Array

0015-3sum
0016-3sum-closest
0018-4sum
0031-next-permutation
0042-trapping-rain-water
0048-rotate-image
0049-group-anagrams
0066-plus-one
0075-sort-colors
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0136-single-number
0152-maximum-product-subarray
0154-find-minimum-in-rotated-sorted-array-ii
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0189-rotate-array
0217-contains-duplicate
0219-contains-duplicate-ii
0229-majority-element-ii
0268-missing-number
0283-move-zeroes
0485-max-consecutive-ones
0496-next-greater-element-i
0581-shortest-unsorted-continuous-subarray
0622-design-circular-queue
0643-maximum-average-subarray-i
0713-subarray-product-less-than-k
0735-asteroid-collision
0744-find-smallest-letter-greater-than-target
0860-lemonade-change
0905-sort-array-by-parity
0907-sum-of-subarray-minimums
0961-n-repeated-element-in-size-2n-array
0977-squares-of-a-sorted-array
0992-subarrays-with-k-different-integers
1200-minimum-absolute-difference
1266-minimum-time-visiting-all-points
1292-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1356-sort-integers-by-the-number-of-1-bits
1390-four-divisors
1458-max-dot-product-of-two-subsequences
1619-mean-of-array-after-removing-some-elements
1823-find-the-winner-of-the-circular-game
1877-minimize-maximum-pair-sum-in-array
1895-largest-magic-square
1975-maximum-matrix-sum
1984-minimum-difference-between-highest-and-lowest-of-k-scores
2104-sum-of-subarray-ranges
2149-rearrange-array-elements-by-sign
2778-sum-of-squares-of-special-elements
2956-find-common-elements-between-two-arrays
2975-maximum-square-area-by-removing-fences-from-a-field
2976-minimum-cost-to-convert-string-i
2977-minimum-cost-to-convert-string-ii
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3013-divide-an-array-into-subarrays-with-minimum-cost-ii
3047-find-the-largest-area-of-square-inside-two-rectangles
3232-find-if-digit-game-can-be-won
3300-minimum-element-after-replacement-with-digit-sum
3314-construct-the-minimum-bitwise-array-i
3315-construct-the-minimum-bitwise-array-ii
3379-transformed-array
3453-separate-squares-i
3454-separate-squares-ii
3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii
3637-trionic-array-i
3640-trionic-array-ii
3719-longest-balanced-subarray-i
3721-longest-balanced-subarray-ii

Hash Table

0003-longest-substring-without-repeating-characters
0049-group-anagrams
0141-linked-list-cycle
0142-linked-list-cycle-ii
0169-majority-element
0202-happy-number
0217-contains-duplicate
0219-contains-duplicate-ii
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0383-ransom-note
0496-next-greater-element-i
0567-permutation-in-string
0865-smallest-subtree-with-all-the-deepest-nodes
0961-n-repeated-element-in-size-2n-array
0987-vertical-order-traversal-of-a-binary-tree
0992-subarrays-with-k-different-integers
2351-first-letter-to-appear-twice
2385-amount-of-time-for-binary-tree-to-be-infected
2956-find-common-elements-between-two-arrays
2975-maximum-square-area-by-removing-fences-from-a-field
3013-divide-an-array-into-subarrays-with-minimum-cost-ii
3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii
3713-longest-balanced-substring-i
3719-longest-balanced-subarray-i
3721-longest-balanced-subarray-ii

Sorting

0015-3sum
0016-3sum-closest
0018-4sum
0049-group-anagrams
0075-sort-colors
0169-majority-element
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0581-shortest-unsorted-continuous-subarray
0905-sort-array-by-parity
0977-squares-of-a-sorted-array
0987-vertical-order-traversal-of-a-binary-tree
1200-minimum-absolute-difference
1356-sort-integers-by-the-number-of-1-bits
1619-mean-of-array-after-removing-some-elements
1877-minimize-maximum-pair-sum-in-array
1984-minimum-difference-between-highest-and-lowest-of-k-scores
3010-divide-an-array-into-subarrays-with-minimum-cost-i

Math

0009-palindrome-number
0048-rotate-image
0066-plus-one
0067-add-binary
0189-rotate-array
0202-happy-number
0268-missing-number
0762-prime-number-of-set-bits-in-binary-representation
1266-minimum-time-visiting-all-points
1390-four-divisors
1823-find-the-winner-of-the-circular-game
3047-find-the-largest-area-of-square-inside-two-rectangles
3232-find-if-digit-game-can-be-won
3300-minimum-element-after-replacement-with-digit-sum

String

0003-longest-substring-without-repeating-characters
0020-valid-parentheses
0049-group-anagrams
0058-length-of-last-word
0067-add-binary
0242-valid-anagram
0383-ransom-note
0567-permutation-in-string
0712-minimum-ascii-delete-sum-for-two-strings
0844-backspace-string-compare
0921-minimum-add-to-make-parentheses-valid
1021-remove-outermost-parentheses
1047-remove-all-adjacent-duplicates-in-string
1249-minimum-remove-to-make-valid-parentheses
2351-first-letter-to-appear-twice
2976-minimum-cost-to-convert-string-i
2977-minimum-cost-to-convert-string-ii
3713-longest-balanced-substring-i
3813-vowel-consonant-score

Bit Manipulation

0067-add-binary
0136-single-number
0190-reverse-bits
0268-missing-number
0762-prime-number-of-set-bits-in-binary-representation
1356-sort-integers-by-the-number-of-1-bits
2351-first-letter-to-appear-twice
3314-construct-the-minimum-bitwise-array-i
3315-construct-the-minimum-bitwise-array-ii

Simulation

0067-add-binary
0735-asteroid-collision
0844-backspace-string-compare
1823-find-the-winner-of-the-circular-game
2149-rearrange-array-elements-by-sign
3379-transformed-array
3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii
3813-vowel-consonant-score

Binary Search

0154-find-minimum-in-rotated-sorted-array-ii
0167-two-sum-ii-input-array-is-sorted
0268-missing-number
0713-subarray-product-less-than-k
0744-find-smallest-letter-greater-than-target
1292-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
3453-separate-squares-i
3454-separate-squares-ii

Dynamic Programming

0042-trapping-rain-water
0085-maximal-rectangle
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0152-maximum-product-subarray
0712-minimum-ascii-delete-sum-for-two-strings
0799-champagne-tower
0907-sum-of-subarray-minimums
1411-number-of-ways-to-paint-n-3-grid
1458-max-dot-product-of-two-subsequences
2977-minimum-cost-to-convert-string-ii
3640-trionic-array-ii

Greedy

0581-shortest-unsorted-continuous-subarray
0860-lemonade-change
0921-minimum-add-to-make-parentheses-valid
1877-minimize-maximum-pair-sum-in-array
1975-maximum-matrix-sum

Matrix

0048-rotate-image
0085-maximal-rectangle
1292-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1895-largest-magic-square
1975-maximum-matrix-sum

Divide and Conquer

0169-majority-element
0190-reverse-bits
3719-longest-balanced-subarray-i
3721-longest-balanced-subarray-ii

Counting

0169-majority-element
0229-majority-element-ii
0383-ransom-note
0992-subarrays-with-k-different-integers
1356-sort-integers-by-the-number-of-1-bits
2351-first-letter-to-appear-twice
3713-longest-balanced-substring-i

Sliding Window

0003-longest-substring-without-repeating-characters
0219-contains-duplicate-ii
0567-permutation-in-string
0643-maximum-average-subarray-i
0713-subarray-product-less-than-k
0992-subarrays-with-k-different-integers
1984-minimum-difference-between-highest-and-lowest-of-k-scores
3013-divide-an-array-into-subarrays-with-minimum-cost-ii

Tree

0094-binary-tree-inorder-traversal
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0236-lowest-common-ancestor-of-a-binary-tree
0437-path-sum-iii
0865-smallest-subtree-with-all-the-deepest-nodes
0987-vertical-order-traversal-of-a-binary-tree
1161-maximum-level-sum-of-a-binary-tree
1339-maximum-product-of-splitted-binary-tree
2385-amount-of-time-for-binary-tree-to-be-infected

Depth-First Search

0094-binary-tree-inorder-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0236-lowest-common-ancestor-of-a-binary-tree
0437-path-sum-iii
0865-smallest-subtree-with-all-the-deepest-nodes
0987-vertical-order-traversal-of-a-binary-tree
1161-maximum-level-sum-of-a-binary-tree
1339-maximum-product-of-splitted-binary-tree
2385-amount-of-time-for-binary-tree-to-be-infected

Breadth-First Search

0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0199-binary-tree-right-side-view
0865-smallest-subtree-with-all-the-deepest-nodes
0987-vertical-order-traversal-of-a-binary-tree
1161-maximum-level-sum-of-a-binary-tree
2385-amount-of-time-for-binary-tree-to-be-infected

Binary Tree

0094-binary-tree-inorder-traversal
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0236-lowest-common-ancestor-of-a-binary-tree
0437-path-sum-iii
0865-smallest-subtree-with-all-the-deepest-nodes
0987-vertical-order-traversal-of-a-binary-tree
1161-maximum-level-sum-of-a-binary-tree
1339-maximum-product-of-splitted-binary-tree
2385-amount-of-time-for-binary-tree-to-be-infected

Enumeration

2778-sum-of-squares-of-special-elements
2975-maximum-square-area-by-removing-fences-from-a-field
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3713-longest-balanced-substring-i

Stack

0020-valid-parentheses
0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0094-binary-tree-inorder-traversal
0114-flatten-binary-tree-to-linked-list
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0155-min-stack
0232-implement-queue-using-stacks
0496-next-greater-element-i
0581-shortest-unsorted-continuous-subarray
0735-asteroid-collision
0844-backspace-string-compare
0907-sum-of-subarray-minimums
0921-minimum-add-to-make-parentheses-valid
1021-remove-outermost-parentheses
1047-remove-all-adjacent-duplicates-in-string
1249-minimum-remove-to-make-valid-parentheses
2104-sum-of-subarray-ranges

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0496-next-greater-element-i
0581-shortest-unsorted-continuous-subarray
0907-sum-of-subarray-minimums
2104-sum-of-subarray-ranges

Geometry

1266-minimum-time-visiting-all-points
3047-find-the-largest-area-of-square-inside-two-rectangles

Segment Tree

3454-separate-squares-ii
3719-longest-balanced-subarray-i
3721-longest-balanced-subarray-ii

Line Sweep

3454-separate-squares-ii

Prefix Sum

0713-subarray-product-less-than-k
1292-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1895-largest-magic-square
3719-longest-balanced-subarray-i
3721-longest-balanced-subarray-ii

Heap (Priority Queue)

3013-divide-an-array-into-subarrays-with-minimum-cost-ii
3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii
3650-minimum-cost-path-with-edge-reversals

Doubly-Linked List

3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii

Ordered Set

3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii

Queue

0232-implement-queue-using-stacks
0622-design-circular-queue
1823-find-the-winner-of-the-circular-game

Design

0155-min-stack
0232-implement-queue-using-stacks
0622-design-circular-queue

Graph Theory

2976-minimum-cost-to-convert-string-i
2977-minimum-cost-to-convert-string-ii
3650-minimum-cost-path-with-edge-reversals

Shortest Path

2976-minimum-cost-to-convert-string-i
2977-minimum-cost-to-convert-string-ii
3650-minimum-cost-path-with-edge-reversals

Trie

2977-minimum-cost-to-convert-string-ii