problem-solving

This is a personal repo for revising Algo

Not all Algo is original some are mine mostly all the upper one While the last one might be someone else's Algo from other platforms Like leet code or geekforgeeks

LeetCode Topics

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0051-n-queens
0053-maximum-subarray
0054-spiral-matrix
0066-plus-one
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0075-sort-colors
0078-subsets
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0121-best-time-to-buy-and-sell-stock
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0212-word-search-ii
0215-kth-largest-element-in-an-array
0238-product-of-array-except-self
0239-sliding-window-maximum
0268-missing-number
0287-find-the-duplicate-number
0303-range-sum-query-immutable
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0697-degree-of-an-array
0747-min-cost-climbing-stairs
0797-rabbits-in-forest
0882-peak-index-in-a-mountain-array
0883-car-fleet
0898-transpose-matrix
0907-koko-eating-bananas
1014-k-closest-points-to-origin
1293-three-consecutive-odds
1656-count-good-triplets
1709-alert-using-same-key-card-three-or-more-times-in-a-one-hour-period
1753-path-with-minimum-effort
1993-sum-of-all-subset-xor-totals
2139-detect-squares
2249-count-the-hidden-sequences
2262-solving-questions-with-brainpower
2277-count-equal-and-divisible-pairs-in-an-array
2280-count-good-triplets-in-an-array
2626-count-the-number-of-good-subarrays
2699-count-the-number-of-fair-pairs
2856-count-complete-subarrays-in-an-array
2891-maximum-beauty-of-an-array-after-applying-operation
3152-maximum-value-of-an-ordered-triplet-ii
3154-maximum-value-of-an-ordered-triplet-i
3685-count-subarrays-of-length-three-with-a-condition

Dynamic Programming

0053-maximum-subarray
0070-climbing-stairs
0121-best-time-to-buy-and-sell-stock
0124-binary-tree-maximum-path-sum
0338-counting-bits
0368-largest-divisible-subset
0392-is-subsequence
0416-partition-equal-subset-sum
0747-min-cost-climbing-stairs
1236-n-th-tribonacci-number
1250-longest-common-subsequence
2262-solving-questions-with-brainpower
2415-count-the-number-of-ideal-arrays
3243-count-the-number-of-powerful-integers

String

0003-longest-substring-without-repeating-characters
0006-zigzag-conversion
0038-count-and-say
0076-minimum-window-substring
0125-valid-palindrome
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0212-word-search-ii
0242-valid-anagram
0297-serialize-and-deserialize-binary-tree
0392-is-subsequence
0424-longest-repeating-character-replacement
0567-permutation-in-string
1023-time-based-key-value-store
1250-longest-common-subsequence
1557-check-if-a-string-contains-all-binary-codes-of-size-k
1709-alert-using-same-key-card-three-or-more-times-in-a-one-hour-period
3243-count-the-number-of-powerful-integers

Two Pointers

0019-remove-nth-node-from-end-of-list
0075-sort-colors
0125-valid-palindrome
0141-linked-list-cycle
0143-reorder-list
0167-two-sum-ii-input-array-is-sorted
0287-find-the-duplicate-number
0295-find-median-from-data-stream
0392-is-subsequence
0567-permutation-in-string
2699-count-the-number-of-fair-pairs

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0074-search-a-2d-matrix
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0268-missing-number
0287-find-the-duplicate-number
0882-peak-index-in-a-mountain-array
0907-koko-eating-bananas
1023-time-based-key-value-store
1753-path-with-minimum-effort
2280-count-good-triplets-in-an-array
2699-count-the-number-of-fair-pairs
2891-maximum-beauty-of-an-array-after-applying-operation

Prefix Sum

0238-product-of-array-except-self
0303-range-sum-query-immutable
2249-count-the-hidden-sequences

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0073-set-matrix-zeroes
0076-minimum-window-substring
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0146-lru-cache
0208-implement-trie-prefix-tree
0242-valid-anagram
0268-missing-number
0424-longest-repeating-character-replacement
0567-permutation-in-string
0697-degree-of-an-array
0797-rabbits-in-forest
1023-time-based-key-value-store
1218-lowest-common-ancestor-of-deepest-leaves
1500-count-largest-group
1557-check-if-a-string-contains-all-binary-codes-of-size-k
1709-alert-using-same-key-card-three-or-more-times-in-a-one-hour-period
2139-detect-squares
2626-count-the-number-of-good-subarrays
2856-count-complete-subarrays-in-an-array

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0023-merge-k-sorted-lists
0025-reverse-nodes-in-k-group
0114-flatten-binary-tree-to-linked-list
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0143-reorder-list
0146-lru-cache
0766-flatten-a-multilevel-doubly-linked-list

Bit Manipulation

0078-subsets
0268-missing-number
0287-find-the-duplicate-number
0338-counting-bits
1557-check-if-a-string-contains-all-binary-codes-of-size-k
1993-sum-of-all-subset-xor-totals

Math

0002-add-two-numbers
0066-plus-one
0070-climbing-stairs
0268-missing-number
0368-largest-divisible-subset
0797-rabbits-in-forest
1014-k-closest-points-to-origin
1236-n-th-tribonacci-number
1500-count-largest-group
1529-max-difference-you-can-get-from-changing-an-integer
1993-sum-of-all-subset-xor-totals
2050-count-good-numbers
2415-count-the-number-of-ideal-arrays
2998-count-symmetric-integers
3243-count-the-number-of-powerful-integers

Sorting

0075-sort-colors
0215-kth-largest-element-in-an-array
0242-valid-anagram
0268-missing-number
0295-find-median-from-data-stream
0368-largest-divisible-subset
0883-car-fleet
1014-k-closest-points-to-origin
1709-alert-using-same-key-card-three-or-more-times-in-a-one-hour-period
2699-count-the-number-of-fair-pairs
2891-maximum-beauty-of-an-array-after-applying-operation

Tree

0098-validate-binary-search-tree
0102-binary-tree-level-order-traversal
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0199-binary-tree-right-side-view
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0297-serialize-and-deserialize-binary-tree
1079-sum-of-root-to-leaf-binary-numbers
1218-lowest-common-ancestor-of-deepest-leaves
1544-count-good-nodes-in-binary-tree

Depth-First Search

0098-validate-binary-search-tree
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0199-binary-tree-right-side-view
0211-design-add-and-search-words-data-structure
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0297-serialize-and-deserialize-binary-tree
0332-reconstruct-itinerary
0744-network-delay-time
0766-flatten-a-multilevel-doubly-linked-list
1079-sum-of-root-to-leaf-binary-numbers
1218-lowest-common-ancestor-of-deepest-leaves
1544-count-good-nodes-in-binary-tree
1753-path-with-minimum-effort

Breadth-First Search

0102-binary-tree-level-order-traversal
0199-binary-tree-right-side-view
0297-serialize-and-deserialize-binary-tree
0744-network-delay-time
1218-lowest-common-ancestor-of-deepest-leaves
1544-count-good-nodes-in-binary-tree
1753-path-with-minimum-effort

Binary Tree

0098-validate-binary-search-tree
0102-binary-tree-level-order-traversal
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0199-binary-tree-right-side-view
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0297-serialize-and-deserialize-binary-tree
1079-sum-of-root-to-leaf-binary-numbers
1218-lowest-common-ancestor-of-deepest-leaves
1544-count-good-nodes-in-binary-tree

Stack

0114-flatten-binary-tree-to-linked-list
0143-reorder-list
0883-car-fleet

Monotonic Stack

0883-car-fleet

Doubly-Linked List

0146-lru-cache
0766-flatten-a-multilevel-doubly-linked-list

Recursion

0002-add-two-numbers
0025-reverse-nodes-in-k-group
0143-reorder-list
2050-count-good-numbers

Backtracking

0051-n-queens
0078-subsets
0212-word-search-ii
1993-sum-of-all-subset-xor-totals

Combinatorics

1993-sum-of-all-subset-xor-totals
2415-count-the-number-of-ideal-arrays

Enumeration

1656-count-good-triplets
1993-sum-of-all-subset-xor-totals
2998-count-symmetric-integers

Design

0146-lru-cache
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0295-find-median-from-data-stream
0297-serialize-and-deserialize-binary-tree
0303-range-sum-query-immutable
1023-time-based-key-value-store
2139-detect-squares

Matrix

0054-spiral-matrix
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0212-word-search-ii
0898-transpose-matrix
1753-path-with-minimum-effort

Divide and Conquer

0004-median-of-two-sorted-arrays
0023-merge-k-sorted-lists
0053-maximum-subarray
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0215-kth-largest-element-in-an-array
1014-k-closest-points-to-origin
2280-count-good-triplets-in-an-array

Heap (Priority Queue)

0023-merge-k-sorted-lists
0215-kth-largest-element-in-an-array
0239-sliding-window-maximum
0295-find-median-from-data-stream
0744-network-delay-time
1014-k-closest-points-to-origin
1753-path-with-minimum-effort

Merge Sort

0023-merge-k-sorted-lists
2280-count-good-triplets-in-an-array

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0239-sliding-window-maximum
0424-longest-repeating-character-replacement
0567-permutation-in-string
2626-count-the-number-of-good-subarrays
2856-count-complete-subarrays-in-an-array
2891-maximum-beauty-of-an-array-after-applying-operation

Queue

0239-sliding-window-maximum

Monotonic Queue

0239-sliding-window-maximum

Binary Search Tree

0098-validate-binary-search-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree

Trie

0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0212-word-search-ii

Geometry

1014-k-closest-points-to-origin

Quickselect

0215-kth-largest-element-in-an-array
1014-k-closest-points-to-origin

Binary Indexed Tree

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

Segment Tree

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

Ordered Set

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

Greedy

0797-rabbits-in-forest
1529-max-difference-you-can-get-from-changing-an-integer

Number Theory

2415-count-the-number-of-ideal-arrays

Data Stream

0295-find-median-from-data-stream

Graph

0332-reconstruct-itinerary
0744-network-delay-time

Shortest Path

0744-network-delay-time

Eulerian Circuit

0332-reconstruct-itinerary

Union Find

1753-path-with-minimum-effort

Counting

2139-detect-squares

Simulation

0054-spiral-matrix
0898-transpose-matrix

Memoization

0070-climbing-stairs
1236-n-th-tribonacci-number

Rolling Hash

1557-check-if-a-string-contains-all-binary-codes-of-size-k

Hash Function

1557-check-if-a-string-contains-all-binary-codes-of-size-k