Leetcode

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

LeetCode Topics

Binary Search

0074-search-a-2d-matrix
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0222-count-complete-tree-nodes
0875-koko-eating-bananas
3113-find-the-number-of-subarrays-where-boundary-elements-are-maximum
3759-count-elements-with-at-least-k-greater-values

Bit Manipulation

0222-count-complete-tree-nodes
0338-counting-bits

Tree

0110-balanced-binary-tree
0222-count-complete-tree-nodes
0404-sum-of-left-leaves
0427-construct-quad-tree
0450-delete-node-in-a-bst
0563-binary-tree-tilt
0669-trim-a-binary-search-tree
0687-longest-univalue-path
0690-employee-importance
0834-sum-of-distances-in-tree
0865-smallest-subtree-with-all-the-deepest-nodes
0951-flip-equivalent-binary-trees
0968-binary-tree-cameras
1377-frog-position-after-t-seconds

Binary Tree

0110-balanced-binary-tree
0222-count-complete-tree-nodes
0404-sum-of-left-leaves
0450-delete-node-in-a-bst
0563-binary-tree-tilt
0669-trim-a-binary-search-tree
0687-longest-univalue-path
0865-smallest-subtree-with-all-the-deepest-nodes
0951-flip-equivalent-binary-trees
0968-binary-tree-cameras

Two Pointers

0011-container-with-most-water
0015-3sum
0042-trapping-rain-water
0125-valid-palindrome
0167-two-sum-ii-input-array-is-sorted
0392-is-subsequence
0567-permutation-in-string
0795-number-of-subarrays-with-bounded-maximum

String

0003-longest-substring-without-repeating-characters
0020-valid-parentheses
0049-group-anagrams
0076-minimum-window-substring
0125-valid-palindrome
0131-palindrome-partitioning
0242-valid-anagram
0392-is-subsequence
0424-longest-repeating-character-replacement
0516-longest-palindromic-subsequence
0567-permutation-in-string
1143-longest-common-subsequence
3760-maximum-substrings-with-distinct-start

Dynamic Programming

0042-trapping-rain-water
0121-best-time-to-buy-and-sell-stock
0131-palindrome-partitioning
0338-counting-bits
0392-is-subsequence
0494-target-sum
0516-longest-palindromic-subsequence
0787-cheapest-flights-within-k-stops
0834-sum-of-distances-in-tree
0968-binary-tree-cameras
1143-longest-common-subsequence
1928-minimum-cost-to-reach-destination-in-time
1976-number-of-ways-to-arrive-at-destination
2110-number-of-smooth-descent-periods-of-a-stock

Array

0001-two-sum
0011-container-with-most-water
0015-3sum
0036-valid-sudoku
0042-trapping-rain-water
0049-group-anagrams
0074-search-a-2d-matrix
0084-largest-rectangle-in-histogram
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0150-evaluate-reverse-polish-notation
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0217-contains-duplicate
0238-product-of-array-except-self
0239-sliding-window-maximum
0304-range-sum-query-2d-immutable
0347-top-k-frequent-elements
0427-construct-quad-tree
0494-target-sum
0690-employee-importance
0739-daily-temperatures
0795-number-of-subarrays-with-bounded-maximum
0851-loud-and-rich
0853-car-fleet
0875-koko-eating-bananas
1020-number-of-enclaves
1248-count-number-of-nice-subarrays
1928-minimum-cost-to-reach-destination-in-time
2110-number-of-smooth-descent-periods-of-a-stock
2444-count-subarrays-with-fixed-bounds
3113-find-the-number-of-subarrays-where-boundary-elements-are-maximum
3531-count-covered-buildings
3741-minimum-distance-between-three-equal-elements-ii
3759-count-elements-with-at-least-k-greater-values
3761-minimum-absolute-distance-between-mirror-pairs

Backtracking

0131-palindrome-partitioning
0494-target-sum

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0036-valid-sudoku
0049-group-anagrams
0076-minimum-window-substring
0128-longest-consecutive-sequence
0217-contains-duplicate
0242-valid-anagram
0347-top-k-frequent-elements
0424-longest-repeating-character-replacement
0567-permutation-in-string
0690-employee-importance
0865-smallest-subtree-with-all-the-deepest-nodes
1248-count-number-of-nice-subarrays
3531-count-covered-buildings
3741-minimum-distance-between-three-equal-elements-ii
3760-maximum-substrings-with-distinct-start
3761-minimum-absolute-distance-between-mirror-pairs

Sorting

0015-3sum
0049-group-anagrams
0217-contains-duplicate
0242-valid-anagram
0347-top-k-frequent-elements
0853-car-fleet
3531-count-covered-buildings
3759-count-elements-with-at-least-k-greater-values

Depth-First Search

0110-balanced-binary-tree
0404-sum-of-left-leaves
0563-binary-tree-tilt
0669-trim-a-binary-search-tree
0687-longest-univalue-path
0690-employee-importance
0743-network-delay-time
0787-cheapest-flights-within-k-stops
0802-find-eventual-safe-states
0834-sum-of-distances-in-tree
0851-loud-and-rich
0865-smallest-subtree-with-all-the-deepest-nodes
0951-flip-equivalent-binary-trees
0968-binary-tree-cameras
1020-number-of-enclaves
1377-frog-position-after-t-seconds

Breadth-First Search

0404-sum-of-left-leaves
0690-employee-importance
0743-network-delay-time
0787-cheapest-flights-within-k-stops
0802-find-eventual-safe-states
0865-smallest-subtree-with-all-the-deepest-nodes
1020-number-of-enclaves
1377-frog-position-after-t-seconds

Binary Search Tree

0450-delete-node-in-a-bst
0669-trim-a-binary-search-tree

Graph

0743-network-delay-time
0787-cheapest-flights-within-k-stops
0802-find-eventual-safe-states
0834-sum-of-distances-in-tree
0851-loud-and-rich
1377-frog-position-after-t-seconds
1928-minimum-cost-to-reach-destination-in-time
1976-number-of-ways-to-arrive-at-destination

Divide and Conquer

0347-top-k-frequent-elements
0427-construct-quad-tree
3759-count-elements-with-at-least-k-greater-values

Matrix

0036-valid-sudoku
0074-search-a-2d-matrix
0304-range-sum-query-2d-immutable
0427-construct-quad-tree
1020-number-of-enclaves

Design

0155-min-stack
0304-range-sum-query-2d-immutable

Prefix Sum

0238-product-of-array-except-self
0304-range-sum-query-2d-immutable
1248-count-number-of-nice-subarrays

Math

0150-evaluate-reverse-polish-notation
1248-count-number-of-nice-subarrays
2110-number-of-smooth-descent-periods-of-a-stock
3761-minimum-absolute-distance-between-mirror-pairs

Quickselect

0347-top-k-frequent-elements
3759-count-elements-with-at-least-k-greater-values

Topological Sort

0802-find-eventual-safe-states
0851-loud-and-rich
1976-number-of-ways-to-arrive-at-destination

Queue

0239-sliding-window-maximum
2444-count-subarrays-with-fixed-bounds

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
1248-count-number-of-nice-subarrays
2444-count-subarrays-with-fixed-bounds

Monotonic Queue

0239-sliding-window-maximum
2444-count-subarrays-with-fixed-bounds

Stack

0020-valid-parentheses
0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0150-evaluate-reverse-polish-notation
0155-min-stack
0739-daily-temperatures
0853-car-fleet
3113-find-the-number-of-subarrays-where-boundary-elements-are-maximum

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0739-daily-temperatures
0853-car-fleet
3113-find-the-number-of-subarrays-where-boundary-elements-are-maximum

Heap (Priority Queue)

0239-sliding-window-maximum
0347-top-k-frequent-elements
0743-network-delay-time
0787-cheapest-flights-within-k-stops

Shortest Path

0743-network-delay-time
0787-cheapest-flights-within-k-stops
1976-number-of-ways-to-arrive-at-destination

Union Find

0128-longest-consecutive-sequence
1020-number-of-enclaves

Bucket Sort

0347-top-k-frequent-elements

Counting

0347-top-k-frequent-elements

Greedy

0011-container-with-most-water