DSA-Practice

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

LeetCode Topics

Array

0001-two-sum
0011-container-with-most-water
0015-3sum
0018-4sum
0027-remove-element
0033-search-in-rotated-sorted-array
0035-search-insert-position
0053-maximum-subarray
0056-merge-intervals
0066-plus-one
0075-sort-colors
0078-subsets
0084-largest-rectangle-in-histogram
0088-merge-sorted-array
0130-surrounded-regions
0136-single-number
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0169-majority-element
0189-rotate-array
0198-house-robber
0200-number-of-islands
0209-minimum-size-subarray-sum
0217-contains-duplicate
0219-contains-duplicate-ii
0228-summary-ranges
0229-majority-element-ii
0238-product-of-array-except-self
0268-missing-number
0283-move-zeroes
0303-range-sum-query-immutable
0322-coin-change
0349-intersection-of-two-arrays
0414-third-maximum-number
0417-pacific-atlantic-water-flow
0435-non-overlapping-intervals
0448-find-all-numbers-disappeared-in-an-array
0463-island-perimeter
0485-max-consecutive-ones
0494-target-sum
0500-keyboard-row
0525-contiguous-array
0542-01-matrix
0566-reshape-the-matrix
0643-maximum-average-subarray-i
0713-subarray-product-less-than-k
0724-find-pivot-index
0733-flood-fill
0778-swim-in-rising-water
0860-lemonade-change
0941-sort-array-by-parity
0961-n-repeated-element-in-size-2n-array
0974-subarray-sums-divisible-by-k
0994-rotting-oranges
1004-max-consecutive-ones-iii
1020-number-of-enclaves
1162-as-far-from-land-as-possible
1252-cells-with-odd-values-in-a-matrix
1254-number-of-closed-islands
1266-minimum-time-visiting-all-points
1343-number-of-sub-arrays-of-size-k-and-average-greater-than-or-equal-to-threshold
1349-check-if-it-is-a-straight-line
1480-running-sum-of-1d-array
1514-path-with-maximum-probability
1582-design-browser-history
1631-path-with-minimum-effort
1695-maximum-erasure-value
1732-find-the-highest-altitude
1765-map-of-highest-peak
1928-minimum-cost-to-reach-destination-in-time
2058-concatenation-of-array
2137-final-value-of-variable-after-performing-operations
2271-rearrange-array-elements-by-sign
2308-divide-array-into-equal-pairs
2574-left-and-right-sum-differences
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3501-delete-nodes-from-linked-list-present-in-array
3515-find-if-digit-game-can-be-won
3531-count-covered-buildings
3581-the-two-sneaky-numbers-of-digitville

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0127-word-ladder
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0169-majority-element
0202-happy-number
0205-isomorphic-strings
0217-contains-duplicate
0219-contains-duplicate-ii
0229-majority-element-ii
0268-missing-number
0349-intersection-of-two-arrays
0448-find-all-numbers-disappeared-in-an-array
0500-keyboard-row
0525-contiguous-array
0567-permutation-in-string
0782-jewels-and-stones
0961-n-repeated-element-in-size-2n-array
0974-subarray-sums-divisible-by-k
1695-maximum-erasure-value
2053-check-if-all-characters-have-equal-number-of-occurrences
2308-divide-array-into-equal-pairs
3501-delete-nodes-from-linked-list-present-in-array
3531-count-covered-buildings
3581-the-two-sneaky-numbers-of-digitville

Divide and Conquer

0053-maximum-subarray
0169-majority-element
0190-reverse-bits

Sorting

0015-3sum
0018-4sum
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0217-contains-duplicate
0229-majority-element-ii
0268-missing-number
0349-intersection-of-two-arrays
0414-third-maximum-number
0435-non-overlapping-intervals
0941-sort-array-by-parity
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3531-count-covered-buildings

Counting

0169-majority-element
0229-majority-element-ii
2053-check-if-all-characters-have-equal-number-of-occurrences
2308-divide-array-into-equal-pairs

Bit Manipulation

0029-divide-two-integers
0067-add-binary
0078-subsets
0136-single-number
0190-reverse-bits
0268-missing-number
2308-divide-array-into-equal-pairs

Two Pointers

0011-container-with-most-water
0015-3sum
0018-4sum
0019-remove-nth-node-from-end-of-list
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0061-rotate-list
0075-sort-colors
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0189-rotate-array
0202-happy-number
0234-palindrome-linked-list
0283-move-zeroes
0349-intersection-of-two-arrays
0392-is-subsequence
0567-permutation-in-string
0908-middle-of-the-linked-list
0941-sort-array-by-parity
2128-reverse-prefix-of-word
2216-delete-the-middle-node-of-a-linked-list
2271-rearrange-array-elements-by-sign

Simulation

0067-add-binary
0412-fizz-buzz
0566-reshape-the-matrix
1195-distribute-candies-to-people
1252-cells-with-odd-values-in-a-matrix
1642-water-bottles
2058-concatenation-of-array
2137-final-value-of-variable-after-performing-operations
2271-rearrange-array-elements-by-sign

String

0003-longest-substring-without-repeating-characters
0013-roman-to-integer
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0020-valid-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0058-length-of-last-word
0067-add-binary
0091-decode-ways
0125-valid-palindrome
0127-word-ladder
0168-excel-sheet-column-title
0171-excel-sheet-column-number
0205-isomorphic-strings
0392-is-subsequence
0412-fizz-buzz
0482-license-key-formatting
0500-keyboard-row
0516-longest-palindromic-subsequence
0567-permutation-in-string
0583-delete-operation-for-two-strings
0782-jewels-and-stones
1456-maximum-number-of-vowels-in-a-substring-of-given-length
2032-largest-odd-number-in-string
2053-check-if-all-characters-have-equal-number-of-occurrences
2128-reverse-prefix-of-word
2137-final-value-of-variable-after-performing-operations

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0013-roman-to-integer
0029-divide-two-integers
0050-powx-n
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0168-excel-sheet-column-title
0171-excel-sheet-column-number
0189-rotate-array
0202-happy-number
0268-missing-number
0412-fizz-buzz
0441-arranging-coins
1195-distribute-candies-to-people
1252-cells-with-odd-values-in-a-matrix
1266-minimum-time-visiting-all-points
1349-check-if-it-is-a-straight-line
1642-water-bottles
1817-calculate-money-in-leetcode-bank
1965-sum-of-digits-in-base-k
2032-largest-odd-number-in-string
2037-count-square-sum-triples
3371-harshad-number
3515-find-if-digit-game-can-be-won
3581-the-two-sneaky-numbers-of-digitville

Enumeration

2037-count-square-sum-triples
3010-divide-an-array-into-subarrays-with-minimum-cost-i

Stack

0020-valid-parentheses
0084-largest-rectangle-in-histogram
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0234-palindrome-linked-list
1582-design-browser-history
2128-reverse-prefix-of-word

Dynamic Programming

0053-maximum-subarray
0070-climbing-stairs
0091-decode-ways
0198-house-robber
0322-coin-change
0392-is-subsequence
0435-non-overlapping-intervals
0494-target-sum
0516-longest-palindromic-subsequence
0542-01-matrix
0583-delete-operation-for-two-strings
0787-cheapest-flights-within-k-stops
1162-as-far-from-land-as-possible
1928-minimum-cost-to-reach-destination-in-time
1976-number-of-ways-to-arrive-at-destination

Binary Search

0033-search-in-rotated-sorted-array
0035-search-insert-position
0069-sqrtx
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0209-minimum-size-subarray-sum
0268-missing-number
0349-intersection-of-two-arrays
0441-arranging-coins
0713-subarray-product-less-than-k
0778-swim-in-rising-water
1004-max-consecutive-ones-iii
1631-path-with-minimum-effort

Geometry

1266-minimum-time-visiting-all-points
1349-check-if-it-is-a-straight-line

Greedy

0011-container-with-most-water
0435-non-overlapping-intervals
0860-lemonade-change
2032-largest-odd-number-in-string

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0061-rotate-list
0083-remove-duplicates-from-sorted-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0203-remove-linked-list-elements
0206-reverse-linked-list
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0328-odd-even-linked-list
0908-middle-of-the-linked-list
1582-design-browser-history
2216-delete-the-middle-node-of-a-linked-list
3501-delete-nodes-from-linked-list-present-in-array

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0050-powx-n
0203-remove-linked-list-elements
0206-reverse-linked-list
0234-palindrome-linked-list

Trie

0014-longest-common-prefix

Design

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0303-range-sum-query-immutable
1582-design-browser-history

Doubly-Linked List

1582-design-browser-history

Data Stream

1582-design-browser-history

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks

Monotonic Stack

0084-largest-rectangle-in-histogram

Sliding Window

0003-longest-substring-without-repeating-characters
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0567-permutation-in-string
0643-maximum-average-subarray-i
0713-subarray-product-less-than-k
1004-max-consecutive-ones-iii
1343-number-of-sub-arrays-of-size-k-and-average-greater-than-or-equal-to-threshold
1456-maximum-number-of-vowels-in-a-substring-of-given-length
1695-maximum-erasure-value

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string

Matrix

0130-surrounded-regions
0200-number-of-islands
0417-pacific-atlantic-water-flow
0463-island-perimeter
0542-01-matrix
0566-reshape-the-matrix
0733-flood-fill
0778-swim-in-rising-water
0994-rotting-oranges
1020-number-of-enclaves
1162-as-far-from-land-as-possible
1254-number-of-closed-islands
1631-path-with-minimum-effort
1765-map-of-highest-peak

Memoization

0070-climbing-stairs

Backtracking

0017-letter-combinations-of-a-phone-number
0078-subsets
0494-target-sum

Breadth-First Search

0102-binary-tree-level-order-traversal
0127-word-ladder
0130-surrounded-regions
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0322-coin-change
0417-pacific-atlantic-water-flow
0463-island-perimeter
0542-01-matrix
0547-number-of-provinces
0733-flood-fill
0743-network-delay-time
0778-swim-in-rising-water
0785-is-graph-bipartite
0787-cheapest-flights-within-k-stops
0802-find-eventual-safe-states
0841-keys-and-rooms
0994-rotting-oranges
1020-number-of-enclaves
1162-as-far-from-land-as-possible
1254-number-of-closed-islands
1319-number-of-operations-to-make-network-connected
1631-path-with-minimum-effort
1765-map-of-highest-peak
1971-find-if-path-exists-in-graph

Depth-First Search

0130-surrounded-regions
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0417-pacific-atlantic-water-flow
0463-island-perimeter
0547-number-of-provinces
0733-flood-fill
0743-network-delay-time
0778-swim-in-rising-water
0785-is-graph-bipartite
0787-cheapest-flights-within-k-stops
0802-find-eventual-safe-states
0841-keys-and-rooms
1020-number-of-enclaves
1254-number-of-closed-islands
1319-number-of-operations-to-make-network-connected
1631-path-with-minimum-effort
1971-find-if-path-exists-in-graph

Union Find

0547-number-of-provinces

Graph

0547-number-of-provinces

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0303-range-sum-query-immutable
0525-contiguous-array
0713-subarray-product-less-than-k
0724-find-pivot-index
0974-subarray-sums-divisible-by-k
1004-max-consecutive-ones-iii
1480-running-sum-of-1d-array
1732-find-the-highest-altitude
2574-left-and-right-sum-differences

Database

0175-combine-two-tables
0185-department-top-three-salaries
1050-actors-and-directors-who-cooperated-at-least-three-times

Tree

0102-binary-tree-level-order-traversal

Binary Tree

0102-binary-tree-level-order-traversal

Union-Find

0130-surrounded-regions
0200-number-of-islands
0547-number-of-provinces
0778-swim-in-rising-water
0785-is-graph-bipartite
1020-number-of-enclaves
1254-number-of-closed-islands
1319-number-of-operations-to-make-network-connected
1631-path-with-minimum-effort
1971-find-if-path-exists-in-graph

Graph Theory

0207-course-schedule
0210-course-schedule-ii
0547-number-of-provinces
0743-network-delay-time
0785-is-graph-bipartite
0787-cheapest-flights-within-k-stops
0802-find-eventual-safe-states
0841-keys-and-rooms
1319-number-of-operations-to-make-network-connected
1514-path-with-maximum-probability
1791-find-center-of-star-graph
1928-minimum-cost-to-reach-destination-in-time
1971-find-if-path-exists-in-graph
1976-number-of-ways-to-arrive-at-destination

Topological Sort

0207-course-schedule
0210-course-schedule-ii
0802-find-eventual-safe-states
1976-number-of-ways-to-arrive-at-destination

Heap (Priority Queue)

0743-network-delay-time
0778-swim-in-rising-water
0787-cheapest-flights-within-k-stops
1514-path-with-maximum-probability
1631-path-with-minimum-effort

Shortest Path

0743-network-delay-time
0787-cheapest-flights-within-k-stops
1514-path-with-maximum-probability
1976-number-of-ways-to-arrive-at-destination