LeetCode practice notes for problems 800 through 899, including A clear explanation of finding the closest shorthand RGB color by rounding each color channel to the nearest repeated hexadecimal pair.
| # | Title | Difficulty | Description |
|---|---|---|---|
| 800 | LeetCode 800: Similar RGB Color | Easy | A clear explanation of finding the closest shorthand RGB color by rounding each color channel to the nearest repeated hexadecimal pair. |
| 801 | LeetCode 801: Minimum Swaps To Make Sequences Increasing | Medium | A dynamic programming solution for finding the minimum number of same-index swaps needed to make two arrays strictly increasing. |
| 802 | LeetCode 802: Find Eventual Safe States | Medium | A graph traversal solution for finding all nodes that cannot reach a directed cycle. |
| 803 | LeetCode 803: Bricks Falling When Hit | Hard | A reverse simulation and union-find solution for counting how many bricks fall after each hit. |
| 804 | LeetCode 804: Unique Morse Code Words | Easy | A set-based solution for counting how many different Morse code transformations appear among a list of words. |
| 805 | LeetCode 805: Split Array With Same Average | Hard | A dynamic programming solution for deciding whether an array can be split into two non-empty groups with the same average. |
| 806 | LeetCode 806: Number of Lines To Write String | Easy | A simple simulation solution for counting how many 100-pixel lines are needed to write a string. |
| 807 | LeetCode 807: Max Increase to Keep City Skyline | Medium | A greedy solution for increasing building heights as much as possible while preserving every skyline view. |
| 808 | LeetCode 808: Soup Servings | Medium | A probability dynamic programming solution for computing whether soup A empties before soup B, with an early return for large input. |
| 809 | LeetCode 809: Expressive Words | Medium | A two-pointer group comparison solution for counting how many words can be stretched to match a target string. |
| 810 | LeetCode 810: Chalkboard XOR Game | Hard | A math and bit manipulation solution for deciding whether Alice wins the XOR removal game. |
| 811 | LeetCode 811: Subdomain Visit Count | Medium | A hash map solution for accumulating visit counts across domains and all of their parent subdomains. |
| 812 | LeetCode 812: Largest Triangle Area | Easy | A geometry solution for finding the largest triangle area by checking every triplet of points with the cross product formula. |
| 813 | LeetCode 813: Largest Sum of Averages | Medium | A dynamic programming and prefix sum solution for partitioning an array into adjacent groups with maximum total average. |
| 814 | LeetCode 814: Binary Tree Pruning | Medium | A postorder DFS solution for removing every binary tree subtree that does not contain a 1. |
| 815 | LeetCode 815: Bus Routes | Hard | A BFS solution for finding the minimum number of buses needed to travel from a source stop to a target stop. |
| 816 | LeetCode 816: Ambiguous Coordinates | Medium | An enumeration solution for reconstructing all valid coordinate pairs after commas, spaces, and decimal points were removed. |
| 817 | LeetCode 817: Linked List Components | Medium | A hash set and linked list traversal solution for counting consecutive components whose values appear in nums. |
| 818 | LeetCode 818: Race Car | Hard | A dynamic programming solution for finding the shortest instruction sequence that drives a race car to the target position. |
| 819 | LeetCode 819: Most Common Word | Easy | A hash map and string parsing solution for finding the most frequent non-banned word in a paragraph. |
| 820 | LeetCode 820: Short Encoding of Words | Medium | A suffix-removal solution for finding the shortest reference string that can encode every word. |
| 821 | LeetCode 821: Shortest Distance to a Character | Easy | A two-pass solution for computing the shortest distance from each index to the nearest occurrence of a target character. |
| 822 | LeetCode 822: Card Flipping Game | Medium | A hash set solution for finding the smallest number that can be hidden from all front-facing cards. |
| 823 | LeetCode 823: Binary Trees With Factors | Medium | A dynamic programming solution for counting binary trees where every non-leaf node is the product of its children. |
| 824 | LeetCode 824: Goat Latin | Easy | A string simulation solution for converting each word in a sentence into Goat Latin. |
| 825 | LeetCode 825: Friends Of Appropriate Ages | Medium | A counting solution for computing how many directed friend requests are allowed by age rules. |
| 826 | LeetCode 826: Most Profit Assigning Work | Medium | A clear explanation of the Most Profit Assigning Work problem using sorting, greedy choice, and two pointers. |
| 827 | LeetCode 827: Making A Large Island | Hard | A clear explanation of the Making A Large Island problem using connected component labeling and island size lookup. |
| 828 | LeetCode 828: Count Unique Characters of All Substrings of a Given String | Hard | A clear explanation of Count Unique Characters of All Substrings using contribution counting with previous and next occurrences. |
| 829 | LeetCode 829: Consecutive Numbers Sum | Hard | A clear explanation of the Consecutive Numbers Sum problem using arithmetic series formulas and divisibility analysis. |
| 830 | LeetCode 830: Positions of Large Groups | Easy | A clear explanation of the Positions of Large Groups problem using a simple two-pointer scan. |
| 831 | LeetCode 831: Masking Personal Information | Medium | A clear explanation of the Masking Personal Information problem using string parsing and format-specific masking rules. |
| 832 | LeetCode 832: Flipping an Image | Easy | A clear explanation of the Flipping an Image problem using row reversal, bit inversion, and an in-place two-pointer method. |
| 833 | LeetCode 833: Find And Replace in String | Medium | A clear explanation of the Find And Replace in String problem using simultaneous replacement, source matching, and a replacement map. |
| 834 | LeetCode 834: Sum of Distances in Tree | Hard | A clear explanation of the Sum of Distances in Tree problem using tree DP, subtree sizes, and rerooting. |
| 835 | LeetCode 835: Image Overlap | Medium | A clear explanation of the Image Overlap problem using translation vectors and frequency counting. |
| 836 | LeetCode 836: Rectangle Overlap | Easy | A clear explanation of the Rectangle Overlap problem using axis projections and positive intersection area. |
| 837 | LeetCode 837: New 21 Game | Medium | A clear explanation of the New 21 Game problem using probability dynamic programming and a sliding window sum. |
| 838 | LeetCode 838: Push Dominoes | Medium | A clear explanation of the Push Dominoes problem using force propagation and a two-pass scan. |
| 839 | LeetCode 839: Similar String Groups | Hard | A clear explanation of the Similar String Groups problem using graph connectivity and union-find. |
| 840 | LeetCode 840: Magic Squares In Grid | Medium | A clear explanation of the Magic Squares In Grid problem using fixed-size subgrid validation. |
| 841 | LeetCode 841: Keys and Rooms | Medium | A clear explanation of the Keys and Rooms problem using graph traversal from room 0. |
| 842 | LeetCode 842: Split Array into Fibonacci Sequence | Medium | A clear explanation of the Split Array into Fibonacci Sequence problem using backtracking, leading-zero checks, and 32-bit integer limits. |
| 843 | LeetCode 843: Guess the Word | Hard | A clear explanation of the Guess the Word interactive problem using candidate filtering and minimax-style guessing. |
| 844 | LeetCode 844: Backspace String Compare | Easy | A clear explanation of the Backspace String Compare problem using stack simulation and an O(1) space two-pointer scan. |
| 845 | LeetCode 845: Longest Mountain in Array | Medium | A clear explanation of the Longest Mountain in Array problem using peak detection and two-pointer expansion. |
| 846 | LeetCode 846: Hand of Straights | Medium | A clear explanation of the Hand of Straights problem using sorting, frequency counting, and greedy grouping. |
| 847 | LeetCode 847: Shortest Path Visiting All Nodes | Hard | A clear explanation of the Shortest Path Visiting All Nodes problem using multi-source BFS and bitmask state compression. |
| 848 | LeetCode 848: Shifting Letters | Medium | A clear explanation of the Shifting Letters problem using suffix sums and modulo arithmetic. |
| 849 | LeetCode 849: Maximize Distance to Closest Person | Medium | A clear explanation of the Maximize Distance to Closest Person problem using gaps between occupied seats. |
| 850 | LeetCode 850: Rectangle Area II | Hard | A clear explanation of the Rectangle Area II problem using sweep line and merged active y-intervals. |
| 851 | LeetCode 851: Loud and Rich | Medium | A clear explanation of Loud and Rich using graph traversal, DFS, and memoization. |
| 852 | LeetCode 852: Peak Index in a Mountain Array | Medium | A clear explanation of finding the peak index in a mountain array using binary search. |
| 853 | LeetCode 853: Car Fleet | Medium | A clear explanation of counting car fleets by sorting cars by position and tracking arrival times. |
| 854 | LeetCode 854: K-Similar Strings | Hard | A clear explanation of finding the minimum number of swaps needed to transform one anagram string into another using BFS. |
| 855 | LeetCode 855: Exam Room | Medium | A clear explanation of simulating an exam room by maintaining occupied seats in sorted order. |
| 856 | LeetCode 856: Score of Parentheses | Medium | A clear explanation of scoring a balanced parentheses string using depth counting. |
| 857 | LeetCode 857: Minimum Cost to Hire K Workers | Hard | A clear explanation of hiring exactly k workers with minimum total cost using wage-to-quality ratios, sorting, and a max heap. |
| 858 | LeetCode 858: Mirror Reflection | Medium | A clear explanation of Mirror Reflection using room unfolding, least common multiples, and parity. |
| 859 | LeetCode 859: Buddy Strings | Easy | A clear explanation of checking whether one swap in a string can make it equal to another string. |
| 860 | LeetCode 860: Lemonade Change | Easy | A clear explanation of Lemonade Change using greedy simulation and bill counting. |
| 861 | LeetCode 861: Score After Flipping Matrix | Medium | A clear explanation of maximizing a binary matrix score using greedy row and column flips. |
| 862 | LeetCode 862: Shortest Subarray with Sum at Least K | Hard | A clear explanation of finding the shortest non-empty subarray with sum at least k using prefix sums and a monotonic deque. |
| 863 | LeetCode 863: All Nodes Distance K in Binary Tree | Medium | A clear explanation of finding all binary tree nodes at distance k from a target node by treating the tree as an undirected graph. |
| 864 | LeetCode 864: Shortest Path to Get All Keys | Hard | A clear explanation of finding the minimum moves to collect all keys in a grid using BFS with key bitmasks. |
| 865 | LeetCode 865: Smallest Subtree with all the Deepest Nodes | Medium | A clear explanation of finding the smallest subtree that contains all deepest nodes using bottom-up DFS. |
| 866 | LeetCode 866: Prime Palindrome | Medium | A clear explanation of finding the smallest prime palindrome greater than or equal to n by generating odd-length palindromes and testing primality. |
| 867 | LeetCode 867: Transpose Matrix | Easy | A clear explanation of transposing a matrix by swapping row and column indices. |
| 868 | LeetCode 868: Binary Gap | Easy | A clear explanation of finding the maximum distance between adjacent set bits in a binary representation. |
| 869 | LeetCode 869: Reordered Power of 2 | Medium | A clear explanation of checking whether the digits of a number can be reordered to form a power of two using digit frequency signatures. |
| 870 | LeetCode 870: Advantage Shuffle | Medium | A clear explanation of maximizing the advantage of one array over another using sorting, greedy matching, and two pointers. |
| 871 | LeetCode 871: Minimum Number of Refueling Stops | Hard | A clear explanation of minimizing refueling stops using a greedy max heap over reachable stations. |
| 872 | LeetCode 872: Leaf-Similar Trees | Easy | A clear explanation of comparing two binary trees by collecting their leaf value sequences with DFS. |
| 873 | LeetCode 873: Length of Longest Fibonacci Subsequence | Medium | A clear explanation of finding the longest Fibonacci-like subsequence using dynamic programming and value-to-index lookup. |
| 874 | LeetCode 874: Walking Robot Simulation | Medium | A clear explanation of simulating robot movement on an infinite grid using direction vectors and obstacle lookup. |
| 875 | LeetCode 875: Koko Eating Bananas | Medium | A clear explanation of finding the minimum banana-eating speed using binary search on the answer. |
| 876 | LeetCode 876: Middle of the Linked List | Easy | A clear explanation of finding the middle node of a singly linked list using slow and fast pointers. |
| 877 | LeetCode 877: Stone Game | Medium | A clear explanation of the Stone Game problem using game theory and interval dynamic programming. |
| 878 | LeetCode 878: Nth Magical Number | Hard | A clear explanation of finding the nth magical number using binary search, greatest common divisor, least common multiple, and inclusion-exclusion. |
| 879 | LeetCode 879: Profitable Schemes | Hard | A clear explanation of counting profitable crime schemes using 0/1 knapsack dynamic programming with members and profit states. |
| 880 | LeetCode 880: Decoded String at Index | Medium | A clear explanation of finding the kth character in a decoded string without building the full decoded string. |
| 881 | LeetCode 881: Boats to Save People | Medium | A clear explanation of minimizing rescue boats using sorting, greedy choice, and two pointers. |
| 882 | LeetCode 882: Reachable Nodes In Subdivided Graph | Hard | A clear explanation of counting reachable original and subdivided nodes using Dijkstra’s shortest path algorithm. |
| 883 | LeetCode 883: Projection Area of 3D Shapes | Easy | A clear explanation of computing the projection areas of stacked cubes from top, front, and side views. |
| 884 | LeetCode 884: Uncommon Words from Two Sentences | Easy | A clear explanation of finding uncommon words by counting word frequencies across both sentences. |
| 885 | LeetCode 885: Spiral Matrix III | Medium | A clear explanation of generating grid coordinates in an outward clockwise spiral using simulation. |
| 886 | LeetCode 886: Possible Bipartition | Medium | A clear explanation of checking whether people can be split into two groups using graph coloring and bipartite graph detection. |
| 887 | LeetCode 887: Super Egg Drop | Hard | A clear explanation of finding the minimum worst-case number of moves using dynamic programming over eggs and moves. |
| 888 | LeetCode 888: Fair Candy Swap | Easy | A clear explanation of finding one candy box swap that makes Alice and Bob have equal total candies. |
| 889 | LeetCode 889: Construct Binary Tree from Preorder and Postorder Traversal | Medium | A clear explanation of reconstructing a binary tree from preorder and postorder traversals using recursion and index ranges. |
| 890 | LeetCode 890: Find and Replace Pattern | Medium | A clear explanation of finding words that match a pattern using bijective character mapping. |
| 891 | LeetCode 891: Sum of Subsequence Widths | Hard | A clear explanation of summing subsequence widths by sorting and counting each element as a maximum and minimum. |
| 892 | LeetCode 892: Surface Area of 3D Shapes | Easy | A clear explanation of computing the exposed surface area of stacked cubes by adding tower area and subtracting shared faces. |
| 893 | LeetCode 893: Groups of Special-Equivalent Strings | Medium | A clear explanation of counting special-equivalent string groups by building canonical signatures from even and odd positions. |
| 894 | LeetCode 894: All Possible Full Binary Trees | Medium | A clear explanation of generating all full binary trees with n nodes using recursion and memoization. |
| 895 | LeetCode 895: Maximum Frequency Stack | Hard | A clear explanation of designing a stack that pops the most frequent value, breaking ties by most recent insertion. |
| 896 | LeetCode 896: Monotonic Array | Easy | A clear explanation of checking whether an array is monotonic using one pass and direction flags. |
| 897 | LeetCode 897: Increasing Order Search Tree | Easy | A clear explanation of rearranging a binary search tree into an increasing right-only tree using inorder traversal. |
| 898 | LeetCode 898: Bitwise ORs of Subarrays | Medium | A clear explanation of counting distinct bitwise OR results from all non-empty subarrays using rolling sets. |
| 899 | LeetCode 899: Orderly Queue | Hard | A clear explanation of finding the lexicographically smallest string after queue operations using rotation and sorting. |
LeetCode 800: Similar RGB ColorA clear explanation of finding the closest shorthand RGB color by rounding each color channel to the nearest repeated hexadecimal pair.
LeetCode 801: Minimum Swaps To Make Sequences IncreasingA dynamic programming solution for finding the minimum number of same-index swaps needed to make two arrays strictly increasing.
LeetCode 802: Find Eventual Safe StatesA graph traversal solution for finding all nodes that cannot reach a directed cycle.
LeetCode 803: Bricks Falling When HitA reverse simulation and union-find solution for counting how many bricks fall after each hit.
LeetCode 804: Unique Morse Code WordsA set-based solution for counting how many different Morse code transformations appear among a list of words.
LeetCode 805: Split Array With Same AverageA dynamic programming solution for deciding whether an array can be split into two non-empty groups with the same average.
LeetCode 806: Number of Lines To Write StringA simple simulation solution for counting how many 100-pixel lines are needed to write a string.
LeetCode 807: Max Increase to Keep City SkylineA greedy solution for increasing building heights as much as possible while preserving every skyline view.
LeetCode 808: Soup ServingsA probability dynamic programming solution for computing whether soup A empties before soup B, with an early return for large input.
LeetCode 809: Expressive WordsA two-pointer group comparison solution for counting how many words can be stretched to match a target string.
LeetCode 810: Chalkboard XOR GameA math and bit manipulation solution for deciding whether Alice wins the XOR removal game.
LeetCode 811: Subdomain Visit CountA hash map solution for accumulating visit counts across domains and all of their parent subdomains.
LeetCode 812: Largest Triangle AreaA geometry solution for finding the largest triangle area by checking every triplet of points with the cross product formula.
LeetCode 813: Largest Sum of AveragesA dynamic programming and prefix sum solution for partitioning an array into adjacent groups with maximum total average.
LeetCode 814: Binary Tree PruningA postorder DFS solution for removing every binary tree subtree that does not contain a 1.
LeetCode 815: Bus RoutesA BFS solution for finding the minimum number of buses needed to travel from a source stop to a target stop.
LeetCode 816: Ambiguous CoordinatesAn enumeration solution for reconstructing all valid coordinate pairs after commas, spaces, and decimal points were removed.
LeetCode 817: Linked List ComponentsA hash set and linked list traversal solution for counting consecutive components whose values appear in nums.
LeetCode 818: Race CarA dynamic programming solution for finding the shortest instruction sequence that drives a race car to the target position.
LeetCode 819: Most Common WordA hash map and string parsing solution for finding the most frequent non-banned word in a paragraph.
LeetCode 820: Short Encoding of WordsA suffix-removal solution for finding the shortest reference string that can encode every word.
LeetCode 821: Shortest Distance to a CharacterA two-pass solution for computing the shortest distance from each index to the nearest occurrence of a target character.
LeetCode 822: Card Flipping GameA hash set solution for finding the smallest number that can be hidden from all front-facing cards.
LeetCode 823: Binary Trees With FactorsA dynamic programming solution for counting binary trees where every non-leaf node is the product of its children.
LeetCode 824: Goat LatinA string simulation solution for converting each word in a sentence into Goat Latin.
LeetCode 825: Friends Of Appropriate AgesA counting solution for computing how many directed friend requests are allowed by age rules.
LeetCode 826: Most Profit Assigning WorkA clear explanation of the Most Profit Assigning Work problem using sorting, greedy choice, and two pointers.
LeetCode 827: Making A Large IslandA clear explanation of the Making A Large Island problem using connected component labeling and island size lookup.
LeetCode 828: Count Unique Characters of All Substrings of a Given StringA clear explanation of Count Unique Characters of All Substrings using contribution counting with previous and next occurrences.
LeetCode 829: Consecutive Numbers SumA clear explanation of the Consecutive Numbers Sum problem using arithmetic series formulas and divisibility analysis.
LeetCode 830: Positions of Large GroupsA clear explanation of the Positions of Large Groups problem using a simple two-pointer scan.
LeetCode 831: Masking Personal InformationA clear explanation of the Masking Personal Information problem using string parsing and format-specific masking rules.
LeetCode 832: Flipping an ImageA clear explanation of the Flipping an Image problem using row reversal, bit inversion, and an in-place two-pointer method.
LeetCode 833: Find And Replace in StringA clear explanation of the Find And Replace in String problem using simultaneous replacement, source matching, and a replacement map.
LeetCode 834: Sum of Distances in TreeA clear explanation of the Sum of Distances in Tree problem using tree DP, subtree sizes, and rerooting.
LeetCode 835: Image OverlapA clear explanation of the Image Overlap problem using translation vectors and frequency counting.
LeetCode 836: Rectangle OverlapA clear explanation of the Rectangle Overlap problem using axis projections and positive intersection area.
LeetCode 837: New 21 GameA clear explanation of the New 21 Game problem using probability dynamic programming and a sliding window sum.
LeetCode 838: Push DominoesA clear explanation of the Push Dominoes problem using force propagation and a two-pass scan.
LeetCode 839: Similar String GroupsA clear explanation of the Similar String Groups problem using graph connectivity and union-find.
LeetCode 840: Magic Squares In GridA clear explanation of the Magic Squares In Grid problem using fixed-size subgrid validation.
LeetCode 841: Keys and RoomsA clear explanation of the Keys and Rooms problem using graph traversal from room 0.
LeetCode 842: Split Array into Fibonacci SequenceA clear explanation of the Split Array into Fibonacci Sequence problem using backtracking, leading-zero checks, and 32-bit integer limits.
LeetCode 843: Guess the WordA clear explanation of the Guess the Word interactive problem using candidate filtering and minimax-style guessing.
LeetCode 844: Backspace String CompareA clear explanation of the Backspace String Compare problem using stack simulation and an O(1) space two-pointer scan.
LeetCode 845: Longest Mountain in ArrayA clear explanation of the Longest Mountain in Array problem using peak detection and two-pointer expansion.
LeetCode 846: Hand of StraightsA clear explanation of the Hand of Straights problem using sorting, frequency counting, and greedy grouping.
LeetCode 847: Shortest Path Visiting All NodesA clear explanation of the Shortest Path Visiting All Nodes problem using multi-source BFS and bitmask state compression.
LeetCode 848: Shifting LettersA clear explanation of the Shifting Letters problem using suffix sums and modulo arithmetic.
LeetCode 849: Maximize Distance to Closest PersonA clear explanation of the Maximize Distance to Closest Person problem using gaps between occupied seats.
LeetCode 850: Rectangle Area IIA clear explanation of the Rectangle Area II problem using sweep line and merged active y-intervals.
LeetCode 851: Loud and RichA clear explanation of Loud and Rich using graph traversal, DFS, and memoization.
LeetCode 852: Peak Index in a Mountain ArrayA clear explanation of finding the peak index in a mountain array using binary search.
LeetCode 853: Car FleetA clear explanation of counting car fleets by sorting cars by position and tracking arrival times.
LeetCode 854: K-Similar StringsA clear explanation of finding the minimum number of swaps needed to transform one anagram string into another using BFS.
LeetCode 855: Exam RoomA clear explanation of simulating an exam room by maintaining occupied seats in sorted order.
LeetCode 856: Score of ParenthesesA clear explanation of scoring a balanced parentheses string using depth counting.
LeetCode 857: Minimum Cost to Hire K WorkersA clear explanation of hiring exactly k workers with minimum total cost using wage-to-quality ratios, sorting, and a max heap.
LeetCode 858: Mirror ReflectionA clear explanation of Mirror Reflection using room unfolding, least common multiples, and parity.
LeetCode 859: Buddy StringsA clear explanation of checking whether one swap in a string can make it equal to another string.
LeetCode 860: Lemonade ChangeA clear explanation of Lemonade Change using greedy simulation and bill counting.
LeetCode 861: Score After Flipping MatrixA clear explanation of maximizing a binary matrix score using greedy row and column flips.
LeetCode 862: Shortest Subarray with Sum at Least KA clear explanation of finding the shortest non-empty subarray with sum at least k using prefix sums and a monotonic deque.
LeetCode 863: All Nodes Distance K in Binary TreeA clear explanation of finding all binary tree nodes at distance k from a target node by treating the tree as an undirected graph.
LeetCode 864: Shortest Path to Get All KeysA clear explanation of finding the minimum moves to collect all keys in a grid using BFS with key bitmasks.
LeetCode 865: Smallest Subtree with all the Deepest NodesA clear explanation of finding the smallest subtree that contains all deepest nodes using bottom-up DFS.
LeetCode 866: Prime PalindromeA clear explanation of finding the smallest prime palindrome greater than or equal to n by generating odd-length palindromes and testing primality.
LeetCode 867: Transpose MatrixA clear explanation of transposing a matrix by swapping row and column indices.
LeetCode 868: Binary GapA clear explanation of finding the maximum distance between adjacent set bits in a binary representation.
LeetCode 869: Reordered Power of 2A clear explanation of checking whether the digits of a number can be reordered to form a power of two using digit frequency signatures.
LeetCode 870: Advantage ShuffleA clear explanation of maximizing the advantage of one array over another using sorting, greedy matching, and two pointers.
LeetCode 871: Minimum Number of Refueling StopsA clear explanation of minimizing refueling stops using a greedy max heap over reachable stations.
LeetCode 872: Leaf-Similar TreesA clear explanation of comparing two binary trees by collecting their leaf value sequences with DFS.
LeetCode 873: Length of Longest Fibonacci SubsequenceA clear explanation of finding the longest Fibonacci-like subsequence using dynamic programming and value-to-index lookup.
LeetCode 874: Walking Robot SimulationA clear explanation of simulating robot movement on an infinite grid using direction vectors and obstacle lookup.
LeetCode 875: Koko Eating BananasA clear explanation of finding the minimum banana-eating speed using binary search on the answer.
LeetCode 876: Middle of the Linked ListA clear explanation of finding the middle node of a singly linked list using slow and fast pointers.
LeetCode 877: Stone GameA clear explanation of the Stone Game problem using game theory and interval dynamic programming.
LeetCode 878: Nth Magical NumberA clear explanation of finding the nth magical number using binary search, greatest common divisor, least common multiple, and inclusion-exclusion.
LeetCode 879: Profitable SchemesA clear explanation of counting profitable crime schemes using 0/1 knapsack dynamic programming with members and profit states.
LeetCode 880: Decoded String at IndexA clear explanation of finding the kth character in a decoded string without building the full decoded string.
LeetCode 881: Boats to Save PeopleA clear explanation of minimizing rescue boats using sorting, greedy choice, and two pointers.
LeetCode 882: Reachable Nodes In Subdivided GraphA clear explanation of counting reachable original and subdivided nodes using Dijkstra's shortest path algorithm.
LeetCode 883: Projection Area of 3D ShapesA clear explanation of computing the projection areas of stacked cubes from top, front, and side views.
LeetCode 884: Uncommon Words from Two SentencesA clear explanation of finding uncommon words by counting word frequencies across both sentences.
LeetCode 885: Spiral Matrix IIIA clear explanation of generating grid coordinates in an outward clockwise spiral using simulation.
LeetCode 886: Possible BipartitionA clear explanation of checking whether people can be split into two groups using graph coloring and bipartite graph detection.
LeetCode 887: Super Egg DropA clear explanation of finding the minimum worst-case number of moves using dynamic programming over eggs and moves.
LeetCode 888: Fair Candy SwapA clear explanation of finding one candy box swap that makes Alice and Bob have equal total candies.
LeetCode 889: Construct Binary Tree from Preorder and Postorder TraversalA clear explanation of reconstructing a binary tree from preorder and postorder traversals using recursion and index ranges.
LeetCode 890: Find and Replace PatternA clear explanation of finding words that match a pattern using bijective character mapping.
LeetCode 891: Sum of Subsequence WidthsA clear explanation of summing subsequence widths by sorting and counting each element as a maximum and minimum.
LeetCode 892: Surface Area of 3D ShapesA clear explanation of computing the exposed surface area of stacked cubes by adding tower area and subtracting shared faces.
LeetCode 893: Groups of Special-Equivalent StringsA clear explanation of counting special-equivalent string groups by building canonical signatures from even and odd positions.
LeetCode 894: All Possible Full Binary TreesA clear explanation of generating all full binary trees with n nodes using recursion and memoization.
LeetCode 895: Maximum Frequency StackA clear explanation of designing a stack that pops the most frequent value, breaking ties by most recent insertion.
LeetCode 896: Monotonic ArrayA clear explanation of checking whether an array is monotonic using one pass and direction flags.
LeetCode 897: Increasing Order Search TreeA clear explanation of rearranging a binary search tree into an increasing right-only tree using inorder traversal.
LeetCode 898: Bitwise ORs of SubarraysA clear explanation of counting distinct bitwise OR results from all non-empty subarrays using rolling sets.
LeetCode 899: Orderly QueueA clear explanation of finding the lexicographically smallest string after queue operations using rotation and sorting.