Leetcode-Solutions-DSA

A collection of LeetCode questions to ace the coding interview! - Created using LeetHub v2

LeetCode Topics

Binary Search

0222-count-complete-tree-nodes
0729-my-calendar-i
0731-my-calendar-ii
0732-my-calendar-iii

Bit Manipulation

0222-count-complete-tree-nodes
1435-xor-queries-of-a-subarray
1786-count-the-number-of-consistent-strings
2170-count-number-of-maximum-bitwise-or-subsets
2323-minimum-bit-flips-to-convert-number
2503-longest-subarray-with-maximum-bitwise-and

Tree

0098-validate-binary-search-tree
0099-recover-binary-search-tree
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0222-count-complete-tree-nodes
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0450-delete-node-in-a-bst
0653-two-sum-iv-input-is-a-bst
0776-n-ary-tree-postorder-traversal
0784-insert-into-a-binary-search-tree
1050-construct-binary-search-tree-from-preorder-traversal
1484-linked-list-in-binary-tree

Binary Tree

0098-validate-binary-search-tree
0099-recover-binary-search-tree
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0222-count-complete-tree-nodes
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0450-delete-node-in-a-bst
0653-two-sum-iv-input-is-a-bst
0784-insert-into-a-binary-search-tree
1050-construct-binary-search-tree-from-preorder-traversal
1484-linked-list-in-binary-tree

Stack

0042-trapping-rain-water
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0776-n-ary-tree-postorder-traversal
0957-minimum-add-to-make-parentheses-valid
1002-maximum-width-ramp
1050-construct-binary-search-tree-from-preorder-traversal
1197-parsing-a-boolean-expression
2095-minimum-number-of-swaps-to-make-the-string-balanced
2800-minimum-string-length-after-removing-substrings

Depth-First Search

0098-validate-binary-search-tree
0099-recover-binary-search-tree
0145-binary-tree-postorder-traversal
0207-course-schedule
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0547-number-of-provinces
0653-two-sum-iv-input-is-a-bst
0776-n-ary-tree-postorder-traversal
1484-linked-list-in-binary-tree
2121-find-if-path-exists-in-graph

Binary Search Tree

0098-validate-binary-search-tree
0099-recover-binary-search-tree
0173-binary-search-tree-iterator
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0450-delete-node-in-a-bst
0653-two-sum-iv-input-is-a-bst
0784-insert-into-a-binary-search-tree
1050-construct-binary-search-tree-from-preorder-traversal

Array

0001-two-sum
0042-trapping-rain-water
0054-spiral-matrix
0088-merge-sorted-array
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0347-top-k-frequent-elements
0435-non-overlapping-intervals
0539-minimum-time-difference
0632-smallest-range-covering-elements-from-k-lists
0729-my-calendar-i
0731-my-calendar-ii
0859-design-circular-deque
0906-walking-robot-simulation
0990-verifying-an-alien-dictionary
1002-maximum-width-ramp
1039-find-the-town-judge
1050-construct-binary-search-tree-from-preorder-traversal
1256-rank-transform-of-an-array
1435-xor-queries-of-a-subarray
1620-check-if-array-pairs-are-divisible-by-k
1694-make-sum-divisible-by-p
1786-count-the-number-of-consistent-strings
1829-maximum-units-on-a-truck
1923-sentence-similarity-iii
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2170-count-number-of-maximum-bitwise-or-subsets
2411-spiral-matrix-iv
2488-divide-intervals-into-minimum-number-of-groups
2494-sum-of-prefix-scores-of-strings
2503-longest-subarray-with-maximum-bitwise-and
2581-divide-players-into-teams-of-equal-skill
3329-find-the-length-of-the-longest-common-prefix

Monotonic Stack

0042-trapping-rain-water
1002-maximum-width-ramp
1050-construct-binary-search-tree-from-preorder-traversal

Matrix

0054-spiral-matrix
2132-convert-1d-array-into-2d-array
2411-spiral-matrix-iv

Simulation

0054-spiral-matrix
0906-walking-robot-simulation
1667-find-kth-bit-in-nth-binary-string
2076-sum-of-digits-of-string-after-convert
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2411-spiral-matrix-iv
2800-minimum-string-length-after-removing-substrings

Design

0173-binary-search-tree-iterator
0208-implement-trie-prefix-tree
0729-my-calendar-i
0731-my-calendar-ii
0732-my-calendar-iii
0859-design-circular-deque

Iterator

0173-binary-search-tree-iterator

Hash Table

0001-two-sum
0208-implement-trie-prefix-tree
0347-top-k-frequent-elements
0567-permutation-in-string
0632-smallest-range-covering-elements-from-k-lists
0653-two-sum-iv-input-is-a-bst
0906-walking-robot-simulation
0920-uncommon-words-from-two-sentences
0990-verifying-an-alien-dictionary
1039-find-the-town-judge
1256-rank-transform-of-an-array
1620-check-if-array-pairs-are-divisible-by-k
1694-make-sum-divisible-by-p
1786-count-the-number-of-consistent-strings
2581-divide-players-into-teams-of-equal-skill
3329-find-the-length-of-the-longest-common-prefix

Two Pointers

0042-trapping-rain-water
0088-merge-sorted-array
0567-permutation-in-string
0653-two-sum-iv-input-is-a-bst
1923-sentence-similarity-iii
2095-minimum-number-of-swaps-to-make-the-string-balanced
2488-divide-intervals-into-minimum-number-of-groups
2581-divide-players-into-teams-of-equal-skill
3195-separate-black-and-white-balls

Breadth-First Search

0207-course-schedule
0547-number-of-provinces
0653-two-sum-iv-input-is-a-bst
1484-linked-list-in-binary-tree
2121-find-if-path-exists-in-graph

String

0208-implement-trie-prefix-tree
0214-shortest-palindrome
0241-different-ways-to-add-parentheses
0539-minimum-time-difference
0567-permutation-in-string
0920-uncommon-words-from-two-sentences
0957-minimum-add-to-make-parentheses-valid
0990-verifying-an-alien-dictionary
1197-parsing-a-boolean-expression
1250-longest-common-subsequence
1667-find-kth-bit-in-nth-binary-string
1786-count-the-number-of-consistent-strings
1923-sentence-similarity-iii
2076-sum-of-digits-of-string-after-convert
2095-minimum-number-of-swaps-to-make-the-string-balanced
2494-sum-of-prefix-scores-of-strings
2800-minimum-string-length-after-removing-substrings
3195-separate-black-and-white-balls
3329-find-the-length-of-the-longest-common-prefix

Math

0007-reverse-integer
0009-palindrome-number
0241-different-ways-to-add-parentheses
0539-minimum-time-difference
0670-maximum-swap
2155-find-missing-observations
2903-insert-greatest-common-divisors-in-linked-list

Union Find

0547-number-of-provinces
2121-find-if-path-exists-in-graph

Graph

0207-course-schedule
0547-number-of-provinces
1039-find-the-town-judge
1916-find-center-of-star-graph
2121-find-if-path-exists-in-graph

Dynamic Programming

0042-trapping-rain-water
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0241-different-ways-to-add-parentheses
0435-non-overlapping-intervals
1250-longest-common-subsequence

Linked List

0725-split-linked-list-in-parts
0859-design-circular-deque
1484-linked-list-in-binary-tree
2411-spiral-matrix-iv
2903-insert-greatest-common-divisors-in-linked-list

Number Theory

2903-insert-greatest-common-divisors-in-linked-list

Counting

0347-top-k-frequent-elements
0920-uncommon-words-from-two-sentences
1620-check-if-array-pairs-are-divisible-by-k
1786-count-the-number-of-consistent-strings
2494-sum-of-prefix-scores-of-strings

Prefix Sum

0731-my-calendar-ii
0732-my-calendar-iii
1435-xor-queries-of-a-subarray
1694-make-sum-divisible-by-p
2488-divide-intervals-into-minimum-number-of-groups

Brainteaser

2503-longest-subarray-with-maximum-bitwise-and

Sorting

0088-merge-sorted-array
0347-top-k-frequent-elements
0435-non-overlapping-intervals
0539-minimum-time-difference
0632-smallest-range-covering-elements-from-k-lists
1256-rank-transform-of-an-array
1829-maximum-units-on-a-truck
2488-divide-intervals-into-minimum-number-of-groups
2581-divide-players-into-teams-of-equal-skill

Topological Sort

0207-course-schedule

Recursion

0241-different-ways-to-add-parentheses
1197-parsing-a-boolean-expression
1667-find-kth-bit-in-nth-binary-string

Memoization

0241-different-ways-to-add-parentheses

Rolling Hash

0214-shortest-palindrome

String Matching

0214-shortest-palindrome

Hash Function

0214-shortest-palindrome

Trie

0208-implement-trie-prefix-tree
2494-sum-of-prefix-scores-of-strings
3329-find-the-length-of-the-longest-common-prefix

Segment Tree

0729-my-calendar-i
0731-my-calendar-ii
0732-my-calendar-iii

Ordered Set

0729-my-calendar-i
0731-my-calendar-ii
0732-my-calendar-iii

Sliding Window

0567-permutation-in-string
0632-smallest-range-covering-elements-from-k-lists

Greedy

0122-best-time-to-buy-and-sell-stock-ii
0435-non-overlapping-intervals
0632-smallest-range-covering-elements-from-k-lists
0670-maximum-swap
0957-minimum-add-to-make-parentheses-valid
1829-maximum-units-on-a-truck
2095-minimum-number-of-swaps-to-make-the-string-balanced
2488-divide-intervals-into-minimum-number-of-groups
3195-separate-black-and-white-balls

Queue

0859-design-circular-deque

Heap (Priority Queue)

0347-top-k-frequent-elements
0632-smallest-range-covering-elements-from-k-lists
2488-divide-intervals-into-minimum-number-of-groups

Divide and Conquer

0347-top-k-frequent-elements

Bucket Sort

0347-top-k-frequent-elements

Quickselect

0347-top-k-frequent-elements

Backtracking

2170-count-number-of-maximum-bitwise-or-subsets

Enumeration

2170-count-number-of-maximum-bitwise-or-subsets