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Hard Problem Index

This index is generated by scripts/generate_difficulty_readmes.py from dataset/merged_problems.json.

Problem count: 686

ID Problem Topics
0004 Median of Two Sorted Arrays Array, Binary Search, Divide and Conquer
0010 Regular Expression Matching String, Dynamic Programming, Recursion
0023 Merge k Sorted Lists Linked List, Divide and Conquer, Heap (Priority Queue), Merge Sort
0025 Reverse Nodes in k-Group Linked List, Recursion
0030 Substring with Concatenation of All Words Hash Table, String, Sliding Window
0032 Longest Valid Parentheses String, Dynamic Programming, Stack
0037 Sudoku Solver Array, Hash Table, Backtracking, Matrix
0041 First Missing Positive Array, Hash Table
0042 Trapping Rain Water Array, Two Pointers, Dynamic Programming, Stack, Monotonic Stack
0044 Wildcard Matching String, Dynamic Programming, Greedy, Recursion
0051 N-Queens Array, Backtracking
0052 N-Queens II Backtracking
0060 Permutation Sequence Math, Recursion
0065 Valid Number String
0068 Text Justification Array, String, Simulation
0076 Minimum Window Substring Hash Table, String, Sliding Window
0084 Largest Rectangle in Histogram Array, Stack, Monotonic Stack
0085 Maximal Rectangle Array, Dynamic Programming, Stack, Matrix, Monotonic Stack
0087 Scramble String String, Dynamic Programming
0115 Distinct Subsequences String, Dynamic Programming
0123 Best Time to Buy and Sell Stock III Array, Dynamic Programming
0124 Binary Tree Maximum Path Sum Dynamic Programming, Tree, Depth-First Search, Binary Tree
0126 Word Ladder II Hash Table, String, Backtracking, Breadth-First Search
0127 Word Ladder Hash Table, String, Breadth-First Search
0132 Palindrome Partitioning II String, Dynamic Programming
0135 Candy Array, Greedy
0140 Word Break II Array, Hash Table, String, Dynamic Programming, Backtracking, Trie, Memoization
0149 Max Points on a Line Array, Hash Table, Math, Geometry
0154 Find Minimum in Rotated Sorted Array II Array, Binary Search
0174 Dungeon Game Array, Dynamic Programming, Matrix
0185 Department Top Three Salaries Database
0188 Best Time to Buy and Sell Stock IV Array, Dynamic Programming
0212 Word Search II Array, String, Backtracking, Trie, Matrix
0214 Shortest Palindrome String, Rolling Hash, String Matching, Hash Function
0218 The Skyline Problem Array, Divide and Conquer, Binary Indexed Tree, Segment Tree, Line Sweep, Heap (Priority Queue), Ordered Set
0220 Contains Duplicate III Array, Sliding Window, Sorting, Bucket Sort, Ordered Set
0224 Basic Calculator Math, String, Stack, Recursion
0233 Number of Digit One Math, Dynamic Programming, Recursion
0239 Sliding Window Maximum Array, Queue, Sliding Window, Heap (Priority Queue), Monotonic Queue
0262 Trips and Users Database
0273 Integer to English Words Math, String, Recursion
0282 Expression Add Operators Math, String, Backtracking
0295 Find Median from Data Stream Two Pointers, Design, Sorting, Heap (Priority Queue), Data Stream
0297 Serialize and Deserialize Binary Tree String, Tree, Depth-First Search, Breadth-First Search, Design, Binary Tree
0301 Remove Invalid Parentheses String, Backtracking, Breadth-First Search
0312 Burst Balloons Array, Dynamic Programming
0315 Count of Smaller Numbers After Self Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set
0321 Create Maximum Number Array, Two Pointers, Stack, Greedy, Monotonic Stack
0327 Count of Range Sum Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set
0329 Longest Increasing Path in a Matrix Array, Dynamic Programming, Depth-First Search, Breadth-First Search, Graph, Topological Sort, Memoization, Matrix
0330 Patching Array Array, Greedy
0332 Reconstruct Itinerary Depth-First Search, Graph, Eulerian Circuit
0335 Self Crossing Array, Math, Geometry
0336 Palindrome Pairs Array, Hash Table, String, Trie
0352 Data Stream as Disjoint Intervals Binary Search, Design, Ordered Set
0354 Russian Doll Envelopes Array, Binary Search, Dynamic Programming, Sorting
0363 Max Sum of Rectangle No Larger Than K Array, Binary Search, Matrix, Prefix Sum, Ordered Set
0381 Insert Delete GetRandom O(1) - Duplicates allowed Array, Hash Table, Math, Design, Randomized
0391 Perfect Rectangle Array, Hash Table, Math, Geometry, Line Sweep
0403 Frog Jump Array, Dynamic Programming
0407 Trapping Rain Water II Array, Breadth-First Search, Heap (Priority Queue), Matrix
0410 Split Array Largest Sum Array, Binary Search, Dynamic Programming, Greedy, Prefix Sum
0420 Strong Password Checker String, Greedy, Heap (Priority Queue)
0432 All O`one Data Structure Hash Table, Linked List, Design, Doubly-Linked List
0440 K-th Smallest in Lexicographical Order Trie
0446 Arithmetic Slices II - Subsequence Array, Dynamic Programming
0458 Poor Pigs Math, Dynamic Programming, Combinatorics
0460 LFU Cache Hash Table, Linked List, Design, Doubly-Linked List
0466 Count The Repetitions String, Dynamic Programming
0472 Concatenated Words Array, String, Dynamic Programming, Depth-First Search, Trie, Sorting
0479 Largest Palindrome Product Math, Enumeration
0480 Sliding Window Median Array, Hash Table, Sliding Window, Heap (Priority Queue)
0483 Smallest Good Base Math, Binary Search
0488 Zuma Game String, Dynamic Programming, Stack, Breadth-First Search, Memoization
0493 Reverse Pairs Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set
0502 IPO Array, Greedy, Sorting, Heap (Priority Queue)
0514 Freedom Trail String, Dynamic Programming, Depth-First Search, Breadth-First Search
0517 Super Washing Machines Array, Greedy
0546 Remove Boxes Array, Dynamic Programming, Memoization
0552 Student Attendance Record II Dynamic Programming
0564 Find the Closest Palindrome Math, String
0587 Erect the Fence Array, Math, Geometry
0591 Tag Validator String, Stack
0600 Non-negative Integers without Consecutive Ones Dynamic Programming
0601 Human Traffic of Stadium Database
0629 K Inverse Pairs Array Dynamic Programming
0630 Course Schedule III Array, Greedy, Sorting, Heap (Priority Queue)
0632 Smallest Range Covering Elements from K Lists Array, Hash Table, Greedy, Sliding Window, Sorting, Heap (Priority Queue)
0639 Decode Ways II String, Dynamic Programming
0664 Strange Printer String, Dynamic Programming
0668 Kth Smallest Number in Multiplication Table Math, Binary Search
0675 Cut Off Trees for Golf Event Array, Breadth-First Search, Heap (Priority Queue), Matrix
0679 24 Game Array, Math, Backtracking
0685 Redundant Connection II Depth-First Search, Breadth-First Search, Union Find, Graph
0689 Maximum Sum of 3 Non-Overlapping Subarrays Array, Dynamic Programming, Sliding Window, Prefix Sum
0691 Stickers to Spell Word Array, Hash Table, String, Dynamic Programming, Backtracking, Bit Manipulation, Memoization, Bitmask
0699 Falling Squares Array, Segment Tree, Ordered Set
0710 Random Pick with Blacklist Array, Hash Table, Math, Binary Search, Sorting, Randomized
0715 Range Module Design, Segment Tree, Ordered Set
0719 Find K-th Smallest Pair Distance Array, Two Pointers, Binary Search, Sorting
0726 Number of Atoms Hash Table, String, Stack, Sorting
0730 Count Different Palindromic Subsequences String, Dynamic Programming
0732 My Calendar III Binary Search, Design, Segment Tree, Prefix Sum, Ordered Set
0736 Parse Lisp Expression Hash Table, String, Stack, Recursion
0741 Cherry Pickup Array, Dynamic Programming, Matrix
0745 Prefix and Suffix Search Array, Hash Table, String, Design, Trie
0749 Contain Virus Array, Depth-First Search, Breadth-First Search, Matrix, Simulation
0753 Cracking the Safe Depth-First Search, Graph, Eulerian Circuit
0757 Set Intersection Size At Least Two Array, Greedy, Sorting
0761 Special Binary String String, Recursion
0765 Couples Holding Hands Greedy, Depth-First Search, Breadth-First Search, Union Find, Graph
0768 Max Chunks To Make Sorted II Array, Stack, Greedy, Sorting, Monotonic Stack
0770 Basic Calculator IV Hash Table, Math, String, Stack, Recursion
0773 Sliding Puzzle Array, Dynamic Programming, Backtracking, Breadth-First Search, Memoization, Matrix
0778 Swim in Rising Water Array, Binary Search, Depth-First Search, Breadth-First Search, Union Find, Heap (Priority Queue), Matrix
0780 Reaching Points Math
0782 Transform to Chessboard Array, Math, Bit Manipulation, Matrix
0793 Preimage Size of Factorial Zeroes Function Math, Binary Search
0798 Smallest Rotation with Highest Score Array, Prefix Sum
0801 Minimum Swaps To Make Sequences Increasing Array, Dynamic Programming
0803 Bricks Falling When Hit Array, Union Find, Matrix
0805 Split Array With Same Average Array, Math, Dynamic Programming, Bit Manipulation, Bitmask
0810 Chalkboard XOR Game Array, Math, Bit Manipulation, Brainteaser, Game Theory
0815 Bus Routes Array, Hash Table, Breadth-First Search
0818 Race Car Dynamic Programming
0827 Making A Large Island Array, Depth-First Search, Breadth-First Search, Union Find, Matrix
0828 Count Unique Characters of All Substrings of a Given String Hash Table, String, Dynamic Programming
0829 Consecutive Numbers Sum Math, Enumeration
0834 Sum of Distances in Tree Dynamic Programming, Tree, Depth-First Search, Graph
0839 Similar String Groups Array, Hash Table, String, Depth-First Search, Breadth-First Search, Union Find
0843 Guess the Word Array, Math, String, Interactive, Game Theory
0847 Shortest Path Visiting All Nodes Dynamic Programming, Bit Manipulation, Breadth-First Search, Graph, Bitmask
0850 Rectangle Area II Array, Segment Tree, Line Sweep, Ordered Set
0854 K-Similar Strings Hash Table, String, Breadth-First Search
0857 Minimum Cost to Hire K Workers Array, Greedy, Sorting, Heap (Priority Queue)
0862 Shortest Subarray with Sum at Least K Array, Binary Search, Queue, Sliding Window, Heap (Priority Queue), Prefix Sum, Monotonic Queue
0864 Shortest Path to Get All Keys Array, Bit Manipulation, Breadth-First Search, Matrix
0871 Minimum Number of Refueling Stops Array, Dynamic Programming, Greedy, Heap (Priority Queue)
0878 Nth Magical Number Math, Binary Search
0879 Profitable Schemes Array, Dynamic Programming
0882 Reachable Nodes In Subdivided Graph Graph, Heap (Priority Queue), Shortest Path
0887 Super Egg Drop Math, Binary Search, Dynamic Programming
0891 Sum of Subsequence Widths Array, Math, Sorting
0895 Maximum Frequency Stack Hash Table, Stack, Design, Ordered Set
0899 Orderly Queue Math, String, Sorting
0902 Numbers At Most N Given Digit Set Array, Math, String, Binary Search, Dynamic Programming
0903 Valid Permutations for DI Sequence String, Dynamic Programming, Prefix Sum
0906 Super Palindromes Math, String, Enumeration
0913 Cat and Mouse Math, Dynamic Programming, Graph, Topological Sort, Memoization, Game Theory
0920 Number of Music Playlists Math, Dynamic Programming, Combinatorics
0924 Minimize Malware Spread Array, Hash Table, Depth-First Search, Breadth-First Search, Union Find, Graph
0927 Three Equal Parts Array, Math
0928 Minimize Malware Spread II Array, Hash Table, Depth-First Search, Breadth-First Search, Union Find, Graph
0936 Stamping The Sequence String, Stack, Greedy, Queue
0940 Distinct Subsequences II String, Dynamic Programming
0943 Find the Shortest Superstring Array, String, Dynamic Programming, Bit Manipulation, Bitmask
0952 Largest Component Size by Common Factor Array, Hash Table, Math, Union Find, Number Theory
0956 Tallest Billboard Array, Dynamic Programming
0960 Delete Columns to Make Sorted III Array, String, Dynamic Programming
0964 Least Operators to Express Number Math, Dynamic Programming, Memoization
0968 Binary Tree Cameras Dynamic Programming, Tree, Depth-First Search, Binary Tree
0972 Equal Rational Numbers Math, String
0975 Odd Even Jump Array, Dynamic Programming, Stack, Sorting, Monotonic Stack, Ordered Set
0980 Unique Paths III Array, Backtracking, Bit Manipulation, Matrix
0982 Triples with Bitwise AND Equal To Zero Array, Hash Table, Bit Manipulation
0987 Vertical Order Traversal of a Binary Tree Hash Table, Tree, Depth-First Search, Breadth-First Search, Sorting, Binary Tree
0992 Subarrays with K Different Integers Array, Hash Table, Sliding Window, Counting
0995 Minimum Number of K Consecutive Bit Flips Array, Bit Manipulation, Queue, Sliding Window, Prefix Sum
0996 Number of Squareful Arrays Array, Hash Table, Math, Dynamic Programming, Backtracking, Bit Manipulation, Bitmask
1000 Minimum Cost to Merge Stones Array, Dynamic Programming, Prefix Sum
1001 Grid Illumination Array, Hash Table
1012 Numbers With Repeated Digits Math, Dynamic Programming
1028 Recover a Tree From Preorder Traversal String, Tree, Depth-First Search, Binary Tree
1032 Stream of Characters Array, String, Design, Trie, Data Stream
1036 Escape a Large Maze Array, Hash Table, Depth-First Search, Breadth-First Search
1044 Longest Duplicate Substring String, Binary Search, Sliding Window, Rolling Hash, Suffix Array, Hash Function
1074 Number of Submatrices That Sum to Target Array, Hash Table, Matrix, Prefix Sum
1092 Shortest Common Supersequence String, Dynamic Programming
1095 Find in Mountain Array Array, Binary Search, Interactive
1096 Brace Expansion II String, Backtracking, Stack, Breadth-First Search
1106 Parsing A Boolean Expression String, Stack, Recursion
1125 Smallest Sufficient Team Array, Dynamic Programming, Bit Manipulation, Bitmask
1147 Longest Chunked Palindrome Decomposition Two Pointers, String, Dynamic Programming, Greedy, Rolling Hash, Hash Function
1157 Online Majority Element In Subarray Array, Binary Search, Design, Binary Indexed Tree, Segment Tree
1163 Last Substring in Lexicographical Order Two Pointers, String
1172 Dinner Plate Stacks Hash Table, Stack, Design, Heap (Priority Queue)
1178 Number of Valid Words for Each Puzzle Array, Hash Table, String, Bit Manipulation, Trie
1187 Make Array Strictly Increasing Array, Binary Search, Dynamic Programming, Sorting
1192 Critical Connections in a Network Depth-First Search, Graph, Biconnected Component
1203 Sort Items by Groups Respecting Dependencies Depth-First Search, Breadth-First Search, Graph, Topological Sort
1206 Design Skiplist Linked List, Design
1210 Minimum Moves to Reach Target with Rotations Array, Breadth-First Search, Matrix
1220 Count Vowels Permutation Dynamic Programming
1223 Dice Roll Simulation Array, Dynamic Programming
1224 Maximum Equal Frequency Array, Hash Table
1235 Maximum Profit in Job Scheduling Array, Binary Search, Dynamic Programming, Sorting
1240 Tiling a Rectangle with the Fewest Squares Backtracking
1250 Check If It Is a Good Array Array, Math, Number Theory
1255 Maximum Score Words Formed by Letters Array, String, Dynamic Programming, Backtracking, Bit Manipulation, Bitmask
1263 Minimum Moves to Move a Box to Their Target Location Array, Breadth-First Search, Heap (Priority Queue), Matrix
1269 Number of Ways to Stay in the Same Place After Some Steps Dynamic Programming
1278 Palindrome Partitioning III String, Dynamic Programming
1284 Minimum Number of Flips to Convert Binary Matrix to Zero Matrix Array, Hash Table, Bit Manipulation, Breadth-First Search, Matrix
1289 Minimum Falling Path Sum II Array, Dynamic Programming, Matrix
1293 Shortest Path in a Grid with Obstacles Elimination Array, Breadth-First Search, Matrix
1298 Maximum Candies You Can Get from Boxes Array, Breadth-First Search, Graph
1301 Number of Paths with Max Score Array, Dynamic Programming, Matrix
1307 Verbal Arithmetic Puzzle Array, Math, String, Backtracking
1312 Minimum Insertion Steps to Make a String Palindrome String, Dynamic Programming
1316 Distinct Echo Substrings String, Trie, Rolling Hash, Hash Function
1320 Minimum Distance to Type a Word Using Two Fingers String, Dynamic Programming
1326 Minimum Number of Taps to Open to Water a Garden Array, Dynamic Programming, Greedy
1330 Reverse Subarray To Maximize Array Value Array, Math, Greedy
1335 Minimum Difficulty of a Job Schedule Array, Dynamic Programming
1340 Jump Game V Array, Dynamic Programming, Sorting
1345 Jump Game IV Array, Hash Table, Breadth-First Search
1349 Maximum Students Taking Exam Array, Dynamic Programming, Bit Manipulation, Matrix, Bitmask
1354 Construct Target Array With Multiple Sums Array, Heap (Priority Queue)
1359 Count All Valid Pickup and Delivery Options Math, Dynamic Programming, Combinatorics
1363 Largest Multiple of Three Array, Math, Dynamic Programming, Greedy, Sorting
1368 Minimum Cost to Make at Least One Valid Path in a Grid Array, Breadth-First Search, Graph, Heap (Priority Queue), Matrix, Shortest Path
1373 Maximum Sum BST in Binary Tree Dynamic Programming, Tree, Depth-First Search, Binary Search Tree, Binary Tree
1377 Frog Position After T Seconds Tree, Depth-First Search, Breadth-First Search, Graph
1383 Maximum Performance of a Team Array, Greedy, Sorting, Heap (Priority Queue)
1388 Pizza With 3n Slices Array, Dynamic Programming, Greedy, Heap (Priority Queue)
1392 Longest Happy Prefix String, Rolling Hash, String Matching, Hash Function
1397 Find All Good Strings String, Dynamic Programming, String Matching
1402 Reducing Dishes Array, Dynamic Programming, Greedy, Sorting
1406 Stone Game III Array, Math, Dynamic Programming, Game Theory
1411 Number of Ways to Paint N × 3 Grid Dynamic Programming
1416 Restore The Array String, Dynamic Programming
1420 Build Array Where You Can Find The Maximum Exactly K Comparisons Dynamic Programming, Prefix Sum
1425 Constrained Subsequence Sum Array, Dynamic Programming, Queue, Sliding Window, Heap (Priority Queue), Monotonic Queue
1434 Number of Ways to Wear Different Hats to Each Other Array, Dynamic Programming, Bit Manipulation, Bitmask
1439 Find the Kth Smallest Sum of a Matrix With Sorted Rows Array, Binary Search, Heap (Priority Queue), Matrix
1444 Number of Ways of Cutting a Pizza Array, Dynamic Programming, Memoization, Matrix, Prefix Sum
1449 Form Largest Integer With Digits That Add up to Target Array, Dynamic Programming
1453 Maximum Number of Darts Inside of a Circular Dartboard Array, Math, Geometry
1458 Max Dot Product of Two Subsequences Array, Dynamic Programming
1463 Cherry Pickup II Array, Dynamic Programming, Matrix
1467 Probability of a Two Boxes Having The Same Number of Distinct Balls Array, Math, Dynamic Programming, Backtracking, Combinatorics, Probability and Statistics
1473 Paint House III Array, Dynamic Programming
1478 Allocate Mailboxes Array, Math, Dynamic Programming, Sorting
1483 Kth Ancestor of a Tree Node Binary Search, Dynamic Programming, Tree, Depth-First Search, Breadth-First Search, Design
1489 Find Critical and Pseudo-Critical Edges in Minimum Spanning Tree Union Find, Graph, Sorting, Minimum Spanning Tree, Strongly Connected Component
1494 Parallel Courses II Dynamic Programming, Bit Manipulation, Graph, Bitmask
1499 Max Value of Equation Array, Queue, Sliding Window, Heap (Priority Queue), Monotonic Queue
1505 Minimum Possible Integer After at Most K Adjacent Swaps On Digits String, Greedy, Binary Indexed Tree, Segment Tree
1510 Stone Game IV Math, Dynamic Programming, Game Theory
1515 Best Position for a Service Centre Array, Math, Geometry, Randomized
1520 Maximum Number of Non-Overlapping Substrings String, Greedy
1521 Find a Value of a Mysterious Function Closest to Target Array, Binary Search, Bit Manipulation, Segment Tree
1526 Minimum Number of Increments on Subarrays to Form a Target Array Array, Dynamic Programming, Stack, Greedy, Monotonic Stack
1531 String Compression II String, Dynamic Programming
1537 Get the Maximum Score Array, Two Pointers, Dynamic Programming, Greedy
1542 Find Longest Awesome Substring Hash Table, String, Bit Manipulation
1547 Minimum Cost to Cut a Stick Array, Dynamic Programming, Sorting
1553 Minimum Number of Days to Eat N Oranges Dynamic Programming, Memoization
1563 Stone Game V Array, Math, Dynamic Programming, Game Theory
1568 Minimum Number of Days to Disconnect Island Array, Depth-First Search, Breadth-First Search, Matrix, Strongly Connected Component
1569 Number of Ways to Reorder Array to Get Same BST Array, Math, Divide and Conquer, Dynamic Programming, Tree, Union Find, Binary Search Tree, Memoization, Combinatorics, Binary Tree
1575 Count All Possible Routes Array, Dynamic Programming, Memoization
1579 Remove Max Number of Edges to Keep Graph Fully Traversable Union Find, Graph
1585 Check If String Is Transformable With Substring Sort Operations String, Greedy, Sorting
1591 Strange Printer II Array, Graph, Topological Sort, Matrix
1595 Minimum Cost to Connect Two Groups of Points Array, Dynamic Programming, Bit Manipulation, Matrix, Bitmask
1601 Maximum Number of Achievable Transfer Requests Array, Backtracking, Bit Manipulation, Enumeration
1606 Find Servers That Handled Most Number of Requests Array, Greedy, Heap (Priority Queue), Ordered Set
1610 Maximum Number of Visible Points Array, Math, Geometry, Sliding Window, Sorting
1611 Minimum One Bit Operations to Make Integers Zero Dynamic Programming, Bit Manipulation, Memoization
1617 Count Subtrees With Max Distance Between Cities Dynamic Programming, Bit Manipulation, Tree, Enumeration, Bitmask
1622 Fancy Sequence Math, Design, Segment Tree
1627 Graph Connectivity With Threshold Array, Math, Union Find, Number Theory
1632 Rank Transform of a Matrix Array, Union Find, Graph, Topological Sort, Sorting, Matrix
1639 Number of Ways to Form a Target String Given a Dictionary Array, String, Dynamic Programming
1643 Kth Smallest Instructions Array, Math, Dynamic Programming, Combinatorics
1649 Create Sorted Array through Instructions Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set
1655 Distribute Repeating Integers Array, Dynamic Programming, Backtracking, Bit Manipulation, Bitmask
1659 Maximize Grid Happiness Dynamic Programming, Bit Manipulation, Memoization, Bitmask
1665 Minimum Initial Energy to Finish Tasks Array, Greedy, Sorting
1671 Minimum Number of Removals to Make Mountain Array Array, Binary Search, Dynamic Programming, Greedy
1675 Minimize Deviation in Array Array, Greedy, Heap (Priority Queue), Ordered Set
1681 Minimum Incompatibility Array, Dynamic Programming, Bit Manipulation, Bitmask
1687 Delivering Boxes from Storage to Ports Array, Dynamic Programming, Segment Tree, Queue, Heap (Priority Queue), Prefix Sum, Monotonic Queue
1691 Maximum Height by Stacking Cuboids Array, Dynamic Programming, Sorting
1697 Checking Existence of Edge Length Limited Paths Array, Two Pointers, Union Find, Graph, Sorting
1703 Minimum Adjacent Swaps for K Consecutive Ones Array, Greedy, Sliding Window, Prefix Sum
1707 Maximum XOR With an Element From Array Array, Bit Manipulation, Trie
1713 Minimum Operations to Make a Subsequence Array, Hash Table, Binary Search, Greedy
1719 Number Of Ways To Reconstruct A Tree Tree, Graph
1723 Find Minimum Time to Finish All Jobs Array, Dynamic Programming, Backtracking, Bit Manipulation, Bitmask
1728 Cat and Mouse II Array, Math, Dynamic Programming, Graph, Topological Sort, Memoization, Matrix, Game Theory
1735 Count Ways to Make Array With Product Array, Math, Dynamic Programming, Combinatorics, Number Theory
1739 Building Boxes Math, Binary Search, Greedy
1745 Palindrome Partitioning IV String, Dynamic Programming
1751 Maximum Number of Events That Can Be Attended II Array, Binary Search, Dynamic Programming, Sorting
1755 Closest Subsequence Sum Array, Two Pointers, Dynamic Programming, Bit Manipulation, Sorting, Bitmask
1761 Minimum Degree of a Connected Trio in a Graph Graph, Enumeration
1766 Tree of Coprimes Array, Math, Tree, Depth-First Search, Number Theory
1770 Maximum Score from Performing Multiplication Operations Array, Dynamic Programming
1771 Maximize Palindrome Length From Subsequences String, Dynamic Programming
1776 Car Fleet II Array, Math, Stack, Heap (Priority Queue), Monotonic Stack
1782 Count Pairs Of Nodes Array, Hash Table, Two Pointers, Binary Search, Graph, Sorting, Counting
1787 Make the XOR of All Segments Equal to Zero Array, Dynamic Programming, Bit Manipulation
1793 Maximum Score of a Good Subarray Array, Two Pointers, Binary Search, Stack, Monotonic Stack
1799 Maximize Score After N Operations Array, Math, Dynamic Programming, Backtracking, Bit Manipulation, Number Theory, Bitmask
1803 Count Pairs With XOR in a Range Array, Bit Manipulation, Trie
1808 Maximize Number of Nice Divisors Math, Recursion, Number Theory
1815 Maximum Number of Groups Getting Fresh Donuts Array, Dynamic Programming, Bit Manipulation, Memoization, Bitmask
1819 Number of Different Subsequences GCDs Array, Math, Counting, Number Theory
1825 Finding MK Average Design, Queue, Heap (Priority Queue), Data Stream, Ordered Set
1830 Minimum Number of Operations to Make String Sorted Math, String, Combinatorics
1835 Find XOR Sum of All Pairs Bitwise AND Array, Math, Bit Manipulation
1840 Maximum Building Height Array, Math, Sorting
1847 Closest Room Array, Binary Search, Sorting, Ordered Set
1851 Minimum Interval to Include Each Query Array, Binary Search, Line Sweep, Sorting, Heap (Priority Queue)
1857 Largest Color Value in a Directed Graph Hash Table, Dynamic Programming, Graph, Topological Sort, Memoization, Counting
1862 Sum of Floored Pairs Array, Math, Binary Search, Prefix Sum
1866 Number of Ways to Rearrange Sticks With K Sticks Visible Math, Dynamic Programming, Combinatorics
1872 Stone Game VIII Array, Math, Dynamic Programming, Prefix Sum, Game Theory
1879 Minimum XOR Sum of Two Arrays Array, Dynamic Programming, Bit Manipulation, Bitmask
1883 Minimum Skips to Arrive at Meeting On Time Array, Dynamic Programming
1889 Minimum Space Wasted From Packaging Array, Binary Search, Sorting, Prefix Sum
1896 Minimum Cost to Change the Final Value of Expression Math, String, Dynamic Programming, Stack
1900 The Earliest and Latest Rounds Where Players Compete Dynamic Programming, Memoization
1912 Design Movie Rental System Array, Hash Table, Design, Heap (Priority Queue), Ordered Set
1916 Count Ways to Build Rooms in an Ant Colony Math, Dynamic Programming, Tree, Graph, Topological Sort, Combinatorics
1923 Longest Common Subpath Array, Binary Search, Rolling Hash, Suffix Array, Hash Function
1928 Minimum Cost to Reach Destination in Time Array, Dynamic Programming, Graph
1931 Painting a Grid With Three Different Colors Dynamic Programming
1932 Merge BSTs to Create Single BST Hash Table, Binary Search, Tree, Depth-First Search, Binary Tree
1938 Maximum Genetic Difference Query Array, Hash Table, Bit Manipulation, Depth-First Search, Trie
1944 Number of Visible People in a Queue Array, Stack, Monotonic Stack
1948 Delete Duplicate Folders in System Array, Hash Table, String, Trie, Hash Function
1955 Count Number of Special Subsequences Array, Dynamic Programming
1960 Maximum Product of the Length of Two Palindromic Substrings String, Rolling Hash, Hash Function
1964 Find the Longest Valid Obstacle Course at Each Position Array, Binary Search, Binary Indexed Tree
1970 Last Day Where You Can Still Cross Array, Binary Search, Depth-First Search, Breadth-First Search, Union Find, Matrix
1977 Number of Ways to Separate Numbers String, Dynamic Programming, Suffix Array
1982 Find Array Given Subset Sums Array, Divide and Conquer
1987 Number of Unique Good Subsequences String, Dynamic Programming
1994 The Number of Good Subsets Array, Hash Table, Math, Dynamic Programming, Bit Manipulation, Counting, Number Theory, Bitmask
1998 GCD Sort of an Array Array, Math, Union Find, Sorting, Number Theory
2003 Smallest Missing Genetic Value in Each Subtree Dynamic Programming, Tree, Depth-First Search, Union Find
2009 Minimum Number of Operations to Make Array Continuous Array, Hash Table, Binary Search, Sliding Window
2014 Longest Subsequence Repeated k Times String, Backtracking, Greedy, Counting, Enumeration
2019 The Score of Students Solving Math Expression Array, Math, String, Dynamic Programming, Stack, Memoization
2025 Maximum Number of Ways to Partition an Array Array, Hash Table, Counting, Enumeration, Prefix Sum
2030 Smallest K-Length Subsequence With Occurrences of a Letter String, Stack, Greedy, Monotonic Stack
2035 Partition Array Into Two Arrays to Minimize Sum Difference Array, Two Pointers, Binary Search, Dynamic Programming, Bit Manipulation, Ordered Set, Bitmask
2040 Kth Smallest Product of Two Sorted Arrays Array, Binary Search
2045 Second Minimum Time to Reach Destination Breadth-First Search, Graph, Shortest Path
2050 Parallel Courses III Array, Dynamic Programming, Graph, Topological Sort
2056 Number of Valid Move Combinations On Chessboard Array, String, Backtracking, Simulation
2060 Check if an Original String Exists Given Two Encoded Strings String, Dynamic Programming
2065 Maximum Path Quality of a Graph Array, Backtracking, Graph
2071 Maximum Number of Tasks You Can Assign Array, Two Pointers, Binary Search, Greedy, Queue, Sorting, Monotonic Queue
2076 Process Restricted Friend Requests Union Find, Graph
2081 Sum of k-Mirror Numbers Math, Enumeration
2088 Count Fertile Pyramids in a Land Array, Dynamic Programming, Matrix
2092 Find All People With Secret Depth-First Search, Breadth-First Search, Union Find, Graph, Sorting
2097 Valid Arrangement of Pairs Depth-First Search, Graph, Eulerian Circuit
2102 Sequentially Ordinal Rank Tracker Design, Heap (Priority Queue), Data Stream, Ordered Set
2106 Maximum Fruits Harvested After at Most K Steps Array, Binary Search, Sliding Window, Prefix Sum
2111 Minimum Operations to Make the Array K-Increasing Array, Binary Search
2117 Abbreviating the Product of a Range Math
2122 Recover the Original Array Array, Hash Table, Two Pointers, Sorting, Enumeration
2127 Maximum Employees to Be Invited to a Meeting Depth-First Search, Graph, Topological Sort
2132 Stamping the Grid Array, Greedy, Matrix, Prefix Sum
2136 Earliest Possible Day of Full Bloom Array, Greedy, Sorting
2141 Maximum Running Time of N Computers Array, Binary Search, Greedy, Sorting
2147 Number of Ways to Divide a Long Corridor Math, String, Dynamic Programming
2151 Maximum Good People Based on Statements Array, Backtracking, Bit Manipulation, Enumeration
2156 Find Substring With Given Hash Value String, Sliding Window, Rolling Hash, Hash Function
2157 Groups of Strings String, Bit Manipulation, Union Find
2163 Minimum Difference in Sums After Removal of Elements Array, Dynamic Programming, Heap (Priority Queue)
2167 Minimum Time to Remove All Cars Containing Illegal Goods String, Dynamic Programming
2172 Maximum AND Sum of Array Array, Dynamic Programming, Bit Manipulation, Bitmask
2179 Count Good Triplets in an Array Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set
2183 Count Array Pairs Divisible by K Array, Math, Number Theory
2188 Minimum Time to Finish the Race Array, Dynamic Programming
2193 Minimum Number of Moves to Make Palindrome Two Pointers, String, Greedy, Binary Indexed Tree
2197 Replace Non-Coprime Numbers in Array Array, Math, Stack, Number Theory
2203 Minimum Weighted Subgraph With the Required Paths Graph, Shortest Path
2209 Minimum White Tiles After Covering With Carpets String, Dynamic Programming, Prefix Sum
2213 Longest Substring of One Repeating Character Array, String, Segment Tree, Ordered Set
2218 Maximum Value of K Coins From Piles Array, Dynamic Programming, Prefix Sum
2223 Sum of Scores of Built Strings String, Binary Search, Rolling Hash, Suffix Array, String Matching, Hash Function
2227 Encrypt and Decrypt Strings Array, Hash Table, String, Design, Trie
2234 Maximum Total Beauty of the Gardens Array, Two Pointers, Binary Search, Greedy, Sorting, Enumeration, Prefix Sum
2242 Maximum Score of a Node Sequence Array, Graph, Sorting, Enumeration
2246 Longest Path With Different Adjacent Characters Array, String, Tree, Depth-First Search, Graph, Topological Sort
2251 Number of Flowers in Full Bloom Array, Hash Table, Binary Search, Sorting, Prefix Sum, Ordered Set
2258 Escape the Spreading Fire Array, Binary Search, Breadth-First Search, Matrix
2262 Total Appeal of A String Hash Table, String, Dynamic Programming
2267 Check if There Is a Valid Parentheses String Path Array, Dynamic Programming, Matrix
2272 Substring With Largest Variance Array, Dynamic Programming
2276 Count Integers in Intervals Design, Segment Tree, Ordered Set
2281 Sum of Total Strength of Wizards Array, Stack, Monotonic Stack, Prefix Sum
2286 Booking Concert Tickets in Groups Binary Search, Design, Binary Indexed Tree, Segment Tree
2290 Minimum Obstacle Removal to Reach Corner Array, Breadth-First Search, Graph, Heap (Priority Queue), Matrix, Shortest Path
2296 Design a Text Editor Linked List, String, Stack, Design, Simulation, Doubly-Linked List
2301 Match Substring After Replacement Array, Hash Table, String, String Matching
2302 Count Subarrays With Score Less Than K Array, Binary Search, Sliding Window, Prefix Sum
2306 Naming a Company Array, Hash Table, String, Bit Manipulation, Enumeration
2312 Selling Pieces of Wood Array, Dynamic Programming, Memoization
2318 Number of Distinct Roll Sequences Dynamic Programming, Memoization
2321 Maximum Score Of Spliced Array Array, Dynamic Programming
2322 Minimum Score After Removals on a Tree Array, Bit Manipulation, Tree, Depth-First Search
2328 Number of Increasing Paths in a Grid Array, Dynamic Programming, Depth-First Search, Breadth-First Search, Graph, Topological Sort, Memoization, Matrix
2334 Subarray With Elements Greater Than Varying Threshold Array, Stack, Union Find, Monotonic Stack
2338 Count the Number of Ideal Arrays Math, Dynamic Programming, Combinatorics, Number Theory
2344 Minimum Deletions to Make Array Divisible Array, Math, Sorting, Heap (Priority Queue), Number Theory
2350 Shortest Impossible Sequence of Rolls Array, Hash Table, Greedy
2354 Number of Excellent Pairs Array, Hash Table, Binary Search, Bit Manipulation
2360 Longest Cycle in a Graph Depth-First Search, Breadth-First Search, Graph, Topological Sort
2366 Minimum Replacements to Sort the Array Array, Math, Greedy
2376 Count Special Integers Math, Dynamic Programming
2382 Maximum Segment Sum After Removals Array, Union Find, Prefix Sum, Ordered Set
2386 Find the K-Sum of an Array Array, Sorting, Heap (Priority Queue)
2392 Build a Matrix With Conditions Array, Graph, Topological Sort, Matrix
2398 Maximum Number of Robots Within Budget Array, Binary Search, Queue, Sliding Window, Heap (Priority Queue), Prefix Sum, Monotonic Queue
2402 Meeting Rooms III Array, Hash Table, Sorting, Heap (Priority Queue), Simulation
2407 Longest Increasing Subsequence II Array, Divide and Conquer, Dynamic Programming, Binary Indexed Tree, Segment Tree, Queue, Monotonic Queue
2412 Minimum Money Required Before Transactions Array, Greedy, Sorting
2416 Sum of Prefix Scores of Strings Array, String, Trie, Counting
2421 Number of Good Paths Array, Hash Table, Tree, Union Find, Graph, Sorting
2426 Number of Pairs Satisfying Inequality Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set
2430 Maximum Deletions on a String String, Dynamic Programming, Rolling Hash, String Matching, Hash Function
2435 Paths in Matrix Whose Sum Is Divisible by K Array, Dynamic Programming, Matrix
2440 Create Components With Same Value Array, Math, Tree, Depth-First Search, Enumeration
2444 Count Subarrays With Fixed Bounds Array, Queue, Sliding Window, Monotonic Queue
2448 Minimum Cost to Make Array Equal Array, Binary Search, Greedy, Sorting, Prefix Sum
2449 Minimum Number of Operations to Make Arrays Similar Array, Greedy, Sorting
2454 Next Greater Element IV Array, Binary Search, Stack, Sorting, Heap (Priority Queue), Monotonic Stack
2458 Height of Binary Tree After Subtree Removal Queries Array, Tree, Depth-First Search, Breadth-First Search, Binary Tree
2463 Minimum Total Distance Traveled Array, Dynamic Programming, Sorting
2468 Split Message Based on Limit String, Binary Search, Enumeration
2472 Maximum Number of Non-overlapping Palindrome Substrings Two Pointers, String, Dynamic Programming, Greedy
2478 Number of Beautiful Partitions String, Dynamic Programming
2484 Count Palindromic Subsequences String, Dynamic Programming
2488 Count Subarrays With Median K Array, Hash Table, Prefix Sum
2493 Divide Nodes Into the Maximum Number of Groups Depth-First Search, Breadth-First Search, Union Find, Graph
2499 Minimum Total Cost to Make Arrays Unequal Array, Hash Table, Greedy, Counting
2503 Maximum Number of Points From Grid Queries Array, Two Pointers, Breadth-First Search, Union Find, Sorting, Heap (Priority Queue), Matrix
2508 Add Edges to Make Degrees of All Nodes Even Hash Table, Graph
2509 Cycle Length Queries in a Tree Array, Tree, Binary Tree
2514 Count Anagrams Hash Table, Math, String, Combinatorics, Counting
2518 Number of Great Partitions Array, Dynamic Programming
2528 Maximize the Minimum Powered City Array, Binary Search, Greedy, Queue, Sliding Window, Prefix Sum
2532 Time to Cross a Bridge Array, Heap (Priority Queue), Simulation
2538 Difference Between Maximum and Minimum Price Sum Array, Dynamic Programming, Tree, Depth-First Search
2543 Check if Point Is Reachable Math, Number Theory
2547 Minimum Cost to Split an Array Array, Hash Table, Dynamic Programming, Counting
2551 Put Marbles in Bags Array, Greedy, Sorting, Heap (Priority Queue)
2552 Count Increasing Quadruplets Array, Dynamic Programming, Binary Indexed Tree, Enumeration, Prefix Sum
2561 Rearranging Fruits Array, Hash Table, Greedy, Sort
2565 Subsequence With the Minimum Score Two Pointers, String, Binary Search
2569 Handling Sum Queries After Update Array, Segment Tree
2573 Find the String with LCP Array, String, Dynamic Programming, Greedy, Union Find, Matrix
2577 Minimum Time to Visit a Cell In a Grid Array, Breadth-First Search, Graph, Heap (Priority Queue), Matrix, Shortest Path
2581 Count Number of Possible Root Nodes Array, Hash Table, Dynamic Programming, Tree, Depth-First Search
2584 Split the Array to Make Coprime Products Array, Hash Table, Math, Number Theory
2585 Number of Ways to Earn Points Array, Dynamic Programming
2589 Minimum Time to Complete All Tasks Array, Binary Search, Stack, Greedy, Sorting
2603 Collect Coins in a Tree Array, Tree, Graph, Topological Sort
2608 Shortest Cycle in a Graph Breadth-First Search, Graph
2612 Minimum Reverse Operations Array, Breadth-First Search, Ordered Set
2617 Minimum Number of Visited Cells in a Grid Array, Dynamic Programming, Stack, Breadth-First Search, Union Find, Heap (Priority Queue), Matrix, Monotonic Stack
2630 Memoize II -
2642 Design Graph With Shortest Path Calculator Graph, Design, Heap (Priority Queue), Shortest Path
2646 Minimize the Total Price of the Trips Array, Dynamic Programming, Tree, Depth-First Search, Graph
2650 Design Cancellable Function -
2659 Make Array Empty Array, Binary Search, Greedy, Binary Indexed Tree, Segment Tree, Sorting, Ordered Set
2663 Lexicographically Smallest Beautiful String String, Greedy
2681 Power of Heroes Array, Math, Dynamic Programming, Sorting, Prefix Sum
2699 Modify Graph Edge Weights Graph, Heap (Priority Queue), Shortest Path
2709 Greatest Common Divisor Traversal Array, Math, Union Find, Number Theory
2713 Maximum Strictly Increasing Cells in a Matrix Array, Hash Table, Binary Search, Dynamic Programming, Memoization, Sorting, Matrix, Ordered Set
2719 Count of Integers Math, String, Dynamic Programming
2732 Find a Good Subset of the Matrix Array, Hash Table, Bit Manipulation, Matrix
2736 Maximum Sum Queries Array, Binary Search, Stack, Binary Indexed Tree, Segment Tree, Sorting, Monotonic Stack
2742 Painting the Walls Array, Dynamic Programming
2751 Robot Collisions Array, Stack, Sorting, Simulation
2763 Sum of Imbalance Numbers of All Subarrays Array, Hash Table, Ordered Set
2781 Length of the Longest Valid Substring Array, Hash Table, String, Sliding Window
2790 Maximum Number of Groups With Increasing Length Array, Math, Binary Search, Greedy, Sorting
2791 Count Paths That Can Form a Palindrome in a Tree Dynamic Programming, Bit Manipulation, Tree, Depth-First Search, Bitmask
2801 Count Stepping Numbers in Range String, Dynamic Programming
2809 Minimum Time to Make Array Sum At Most x Array, Dynamic Programming, Sorting
2813 Maximum Elegance of a K-Length Subsequence Array, Hash Table, Stack, Greedy, Sorting, Heap (Priority Queue)
2818 Apply Operations to Maximize Score Array, Math, Stack, Greedy, Sorting, Monotonic Stack, Number Theory
2827 Number of Beautiful Integers in the Range Math, Dynamic Programming
2835 Minimum Operations to Form Subsequence With Target Sum Array, Greedy, Bit Manipulation
2836 Maximize Value of Function in a Ball Passing Game Array, Dynamic Programming, Bit Manipulation
2842 Count K-Subsequences of a String With Maximum Beauty Hash Table, Math, String, Greedy, Combinatorics
2846 Minimum Edge Weight Equilibrium Queries in a Tree Array, Tree, Graph, Strongly Connected Component
2851 String Transformation Math, String, Dynamic Programming, String Matching
2858 Minimum Edge Reversals So Every Node Is Reachable Dynamic Programming, Depth-First Search, Breadth-First Search, Graph
2862 Maximum Element-Sum of a Complete Subset of Indices Array, Math, Number Theory
2867 Count Valid Paths in a Tree Math, Dynamic Programming, Tree, Depth-First Search, Number Theory
2872 Maximum Number of K-Divisible Components Tree, Depth-First Search
2876 Count Visited Nodes in a Directed Graph Dynamic Programming, Graph, Memoization
2897 Apply Operations on Array to Maximize Sum of Squares Array, Hash Table, Greedy, Bit Manipulation
2902 Count of Sub-Multisets With Bounded Sum Array, Hash Table, Dynamic Programming, Sliding Window
2911 Minimum Changes to Make K Semi-palindromes Two Pointers, String, Dynamic Programming
2916 Subarrays Distinct Element Sum of Squares II Array, Dynamic Programming, Binary Indexed Tree, Segment Tree
2920 Maximum Points After Collecting Coins From All Nodes Array, Dynamic Programming, Bit Manipulation, Tree, Depth-First Search, Memoization
2926 Maximum Balanced Subsequence Sum Array, Binary Search, Dynamic Programming, Binary Indexed Tree, Segment Tree
2931 Maximum Spending After Buying Items Array, Greedy, Sorting, Heap (Priority Queue), Matrix
2935 Maximum Strong Pair XOR II Array, Hash Table, Bit Manipulation, Trie, Sliding Window
2940 Find Building Where Alice and Bob Can Meet Array, Binary Search, Stack, Binary Indexed Tree, Segment Tree, Heap (Priority Queue), Monotonic Stack
2945 Find Maximum Non-decreasing Array Length Array, Binary Search, Dynamic Programming, Stack, Queue, Monotonic Stack, Monotonic Queue
2949 Count Beautiful Substrings II Hash Table, Math, String, Number Theory, Prefix Sum
2953 Count Complete Substrings Hash Table, String, Sliding Window
2954 Count the Number of Infection Sequences Array, Math, Combinatorics
2959 Number of Possible Sets of Closing Branches Bit Manipulation, Graph, Heap (Priority Queue), Enumeration, Shortest Path
2963 Count the Number of Good Partitions Array, Hash Table, Math, Combinatorics
2968 Apply Operations to Maximize Frequency Score Array, Binary Search, Sliding Window, Sorting, Prefix Sum
2972 Count the Number of Incremovable Subarrays II Array, Two Pointers, Binary Search
2973 Find Number of Coins to Place in Tree Nodes Dynamic Programming, Tree, Depth-First Search, Sorting, Heap (Priority Queue)
2977 Minimum Cost to Convert String II Array, String, Dynamic Programming, Graph, Trie, Shortest Path
2983 Palindrome Rearrangement Queries Hash Table, String, Prefix Sum
2999 Count the Number of Powerful Integers Math, String, Dynamic Programming
3003 Maximize the Number of Partitions After Operations String, Dynamic Programming, Bit Manipulation, Bitmask
3008 Find Beautiful Indices in the Given Array II Two Pointers, String, Binary Search, Rolling Hash, String Matching, Hash Function
3013 Divide an Array Into Subarrays With Minimum Cost II Array, Hash Table, Sliding Window, Heap (Priority Queue)
3017 Count the Number of Houses at a Certain Distance II Graph, Prefix Sum
3022 Minimize OR of Remaining Elements Using Operations Array, Greedy, Bit Manipulation
3027 Find the Number of Ways to Place People II Array, Math, Geometry, Sorting, Enumeration
3031 Minimum Time to Revert Word to Initial State II String, Rolling Hash, String Matching, Hash Function
3036 Number of Subarrays That Match a Pattern II Array, Rolling Hash, String Matching, Hash Function
3041 Maximize Consecutive Elements in an Array After Modification Array, Dynamic Programming, Sorting
3045 Count Prefix and Suffix Pairs II Array, String, Trie, Rolling Hash, String Matching, Hash Function
3049 Earliest Second to Mark Indices II Array, Binary Search, Greedy, Heap (Priority Queue)
3068 Find the Maximum Sum of Node Values Array, Dynamic Programming, Greedy, Bit Manipulation, Tree, Sorting
3072 Distribute Elements Into Two Arrays II Array, Binary Indexed Tree, Segment Tree, Simulation
3077 Maximum Strength of K Disjoint Subarrays Array, Dynamic Programming, Prefix Sum
3082 Find the Sum of the Power of All Subsequences Array, Dynamic Programming
3086 Minimum Moves to Pick K Ones Array, Greedy, Sliding Window, Prefix Sum
3093 Longest Common Suffix Queries Array, String, Trie
3098 Find the Sum of Subsequence Powers Array, Dynamic Programming, Sorting
3102 Minimize Manhattan Distances Array, Math, Geometry, Sorting, Ordered Set
3108 Minimum Cost Walk in Weighted Graph Array, Bit Manipulation, Union Find, Graph
3113 Find the Number of Subarrays Where Boundary Elements Are Maximum Array, Binary Search, Stack, Monotonic Stack
3116 Kth Smallest Amount With Single Denomination Combination Array, Math, Binary Search, Bit Manipulation, Combinatorics, Number Theory
3117 Minimum Sum of Values by Dividing Array Array, Binary Search, Dynamic Programming, Bit Manipulation, Segment Tree, Queue
3123 Find Edges in Shortest Paths Depth-First Search, Breadth-First Search, Graph, Heap (Priority Queue), Shortest Path
3130 Find All Possible Stable Binary Arrays II Dynamic Programming, Prefix Sum
3134 Find the Median of the Uniqueness Array Array, Hash Table, Binary Search, Sliding Window
3139 Minimum Cost to Equalize Array Array, Greedy, Enumeration
3145 Find Products of Elements of Big Array Array, Binary Search, Bit Manipulation
3149 Find the Minimum Cost Array Permutation Array, Dynamic Programming, Bit Manipulation, Bitmask
3154 Find Number of Ways to Reach the K-th Stair Math, Dynamic Programming, Bit Manipulation, Memoization, Combinatorics
3161 Block Placement Queries Array, Binary Search, Binary Indexed Tree, Segment Tree
3165 Maximum Sum of Subsequence With Non-adjacent Elements Array, Divide and Conquer, Dynamic Programming, Segment Tree
3171 Find Subarray With Bitwise OR Closest to K Array, Binary Search, Bit Manipulation, Segment Tree
3177 Find the Maximum Length of a Good Subsequence II Array, Hash Table, Dynamic Programming
3181 Maximum Total Reward Using Operations II Array, Dynamic Programming, Bit Manipulation
3187 Peaks in Array Array, Binary Indexed Tree, Segment Tree
3193 Count the Number of Inversions Array, Dynamic Programming
3197 Find the Minimum Area to Cover All Ones II Array, Matrix, Enumeration
3203 Find Minimum Diameter After Merging Two Trees Tree, Depth-First Search, Breadth-First Search, Graph
3209 Number of Subarrays With AND Value of K Array, Binary Search, Bit Manipulation, Segment Tree
3213 Construct String with Minimum Cost Array, String, Dynamic Programming, Suffix Array
3219 Minimum Cost for Cutting Cake II Array, Greedy, Sorting
3225 Maximum Score From Grid Operations Array, Dynamic Programming, Matrix, Prefix Sum
3229 Minimum Operations to Make Array Equal to Target Array, Dynamic Programming, Stack, Greedy, Monotonic Stack
3235 Check if the Rectangle Corner Is Reachable Array, Math, Depth-First Search, Breadth-First Search, Union Find, Geometry
3241 Time Taken to Mark All Nodes Dynamic Programming, Tree, Depth-First Search, Graph
3244 Shortest Distance After Road Addition Queries II Array, Greedy, Graph, Ordered Set
3245 Alternating Groups III Array, Binary Indexed Tree
3250 Find the Count of Monotonic Pairs I Array, Math, Dynamic Programming, Combinatorics, Prefix Sum
3251 Find the Count of Monotonic Pairs II Array, Math, Dynamic Programming, Combinatorics, Prefix Sum
3256 Maximum Value Sum by Placing Three Rooks I Array, Dynamic Programming, Matrix, Enumeration
3257 Maximum Value Sum by Placing Three Rooks II Array, Dynamic Programming, Matrix, Enumeration
3260 Find the Largest Palindrome Divisible by K Math, String, Dynamic Programming, Greedy, Number Theory
3261 Count Substrings That Satisfy K-Constraint II Array, String, Binary Search, Sliding Window, Prefix Sum
3266 Final Array State After K Multiplication Operations II Array, Heap (Priority Queue), Simulation
3267 Count Almost Equal Pairs II Array, Hash Table, Sorting, Counting, Enumeration
3272 Find the Count of Good Integers Hash Table, Math, Combinatorics, Enumeration
3273 Minimum Amount of Damage Dealt to Bob Array, Greedy, Sorting
3276 Select Cells in Grid With Maximum Score Array, Dynamic Programming, Bit Manipulation, Matrix, Bitmask
3277 Maximum XOR Score Subarray Queries Array, Dynamic Programming
3283 Maximum Number of Moves to Kill All Pawns Array, Math, Bit Manipulation, Breadth-First Search, Game Theory, Bitmask
3287 Find the Maximum Sequence Value of Array Array, Dynamic Programming, Bit Manipulation
3288 Length of the Longest Increasing Path Array, Binary Search, Sorting
3292 Minimum Number of Valid Strings to Form Target II Array, String, Binary Search, Dynamic Programming, Segment Tree, Rolling Hash, String Matching, Hash Function
3298 Count Substrings That Can Be Rearranged to Contain a String II Hash Table, String, Sliding Window
3303 Find the Occurrence of First Almost Equal Substring String, String Matching
3307 Find the K-th Character in String Game II Math, Bit Manipulation, Recursion
3311 Construct 2D Grid Matching Graph Layout Array, Hash Table, Graph, Matrix
3312 Sorted GCD Pair Queries Array, Hash Table, Math, Binary Search, Combinatorics, Counting, Number Theory, Prefix Sum
3317 Find the Number of Possible Ways for an Event Math, Dynamic Programming, Combinatorics
3320 Count The Number of Winning Sequences String, Dynamic Programming
3321 Find X-Sum of All K-Long Subarrays II Array, Hash Table, Sliding Window, Heap (Priority Queue)
3327 Check if DFS Strings Are Palindromes Array, Hash Table, String, Tree, Depth-First Search, Hash Function
3333 Find the Original Typed String II String, Dynamic Programming, Prefix Sum
3336 Find the Number of Subsequences With Equal GCD Array, Math, Dynamic Programming, Number Theory
3337 Total Characters in String After Transformations II Hash Table, Math, String, Dynamic Programming, Counting
3343 Count Number of Balanced Permutations Math, String, Dynamic Programming, Combinatorics
3347 Maximum Frequency of an Element After Performing Operations II Array, Binary Search, Sliding Window, Sorting, Prefix Sum
3348 Smallest Divisible Digit Product II Math, String, Backtracking, Greedy, Number Theory
3351 Sum of Good Subsequences Array, Hash Table, Dynamic Programming
3352 Count K-Reducible Numbers Less Than N Math, String, Dynamic Programming, Combinatorics
3357 Minimize the Maximum Adjacent Element Difference Array, Binary Search, Greedy
3363 Find the Maximum Number of Fruits Collected Array, Dynamic Programming, Matrix
3367 Maximize Sum of Weights after Edge Removals Dynamic Programming, Tree, Depth-First Search
3373 Maximize the Number of Target Nodes After Connecting Trees II Tree, Depth-First Search, Breadth-First Search
3374 First Letter Capitalization II Database
3378 Count Connected Components in LCM Graph Array, Hash Table, Math, Union Find, Number Theory
3382 Maximum Area Rectangle With Point Constraints II Array, Math, Binary Indexed Tree, Segment Tree, Geometry, Sorting
3389 Minimum Operations to Make Character Frequencies Equal Hash Table, String, Dynamic Programming, Counting, Enumeration
3395 Subsequences with a Unique Middle Mode I Array, Hash Table, Math, Combinatorics
3398 Smallest Substring With Identical Characters I Array, Binary Search, Enumeration
3399 Smallest Substring With Identical Characters II String, Binary Search
3405 Count the Number of Arrays with K Matching Adjacent Elements Math, Combinatorics
3410 Maximize Subarray Sum After Removing All Occurrences of One Element Array, Dynamic Programming, Segment Tree
3414 Maximum Score of Non-overlapping Intervals Array, Binary Search, Dynamic Programming, Sorting
3420 Count Non-Decreasing Subarrays After K Operations Array, Stack, Segment Tree, Queue, Sliding Window, Monotonic Stack, Monotonic Queue
3425 Longest Special Path Array, Hash Table, Tree, Depth-First Search, Prefix Sum
3426 Manhattan Distances of All Arrangements of Pieces Math, Combinatorics
3430 Maximum and Minimum Sums of at Most Size K Subarrays Array, Math, Stack, Monotonic Stack
3435 Frequencies of Shortest Supersequences Array, String, Bit Manipulation, Graph, Topological Sort, Enumeration
3441 Minimum Cost Good Caption String, Dynamic Programming
3444 Minimum Increments for Target Multiples in an Array Array, Math, Dynamic Programming, Bit Manipulation, Number Theory, Bitmask
3445 Maximum Difference Between Even and Odd Frequency II String, Sliding Window, Enumeration, Prefix Sum
3448 Count Substrings Divisible By Last Digit String, Dynamic Programming
3449 Maximize the Minimum Game Score Array, Binary Search, Greedy
3451 Find Invalid IP Addresses Database
3454 Separate Squares II Array, Binary Search, Segment Tree, Line Sweep
3455 Shortest Matching Substring Two Pointers, String, Binary Search, String Matching
3459 Length of Longest V-Shaped Diagonal Segment Array, Dynamic Programming, Memoization, Matrix
3463 Check If Digits Are Equal in String After Operations II Math, String, Combinatorics, Number Theory
3464 Maximize the Distance Between Points on a Square Array, Binary Search, Greedy
3470 Permutations IV Array, Math, Combinatorics, Enumeration
3474 Lexicographically Smallest Generated String String, Greedy, String Matching
3480 Maximize Subarrays After Removing One Conflicting Pair Array, Segment Tree, Enumeration, Prefix Sum
3482 Analyze Organization Hierarchy Database
3485 Longest Common Prefix of K Strings After Removal Array, String, Trie
3486 Longest Special Path II Array, Hash Table, Tree, Depth-First Search, Prefix Sum
3490 Count Beautiful Numbers Dynamic Programming
3495 Minimum Operations to Make Array Elements Zero Array, Math, Bit Manipulation
3500 Minimum Cost to Divide Array Into Subarrays Array, Dynamic Programming, Prefix Sum
3501 Maximize Active Section with Trade II Array, String, Binary Search, Segment Tree
3504 Longest Palindrome After Substring Concatenation II Two Pointers, String, Dynamic Programming
3505 Minimum Operations to Make Elements Within K Subarrays Equal Array, Hash Table, Math, Dynamic Programming, Sliding Window, Heap (Priority Queue)
3509 Maximum Product of Subsequences With an Alternating Sum Equal to K Array, Hash Table, Dynamic Programming
3510 Minimum Pair Removal to Sort Array II Array, Hash Table, Linked List, Heap (Priority Queue), Simulation, Doubly-Linked List, Ordered Set
3515 Shortest Path in a Weighted Tree Array, Tree, Depth-First Search, Binary Indexed Tree, Segment Tree
3518 Smallest Palindromic Rearrangement II Hash Table, Math, String, Combinatorics, Counting
3519 Count Numbers with Non-Decreasing Digits Math, String, Dynamic Programming
3525 Find X Value of Array II Array, Math, Segment Tree
3530 Maximum Profit from Valid Topological Order in DAG Array, Dynamic Programming, Bit Manipulation, Graph, Topological Sort, Bitmask
3533 Concatenated Divisibility Array, Dynamic Programming, Bit Manipulation, Bitmask
3534 Path Existence Queries in a Graph II Array, Binary Search, Greedy, Graph, Sorting
3538 Merge Operations for Minimum Travel Time Array, Dynamic Programming, Prefix Sum
3539 Find Sum of Array Product of Magical Sequences Array, Math, Dynamic Programming, Bit Manipulation, Combinatorics, Bitmask
3544 Subtree Inversion Sum Array, Dynamic Programming, Tree, Depth-First Search
3547 Maximum Sum of Edge Values in a Graph Greedy, Depth-First Search, Graph, Sorting
3548 Equal Sum Grid Partition II Array, Hash Table, Matrix, Enumeration, Prefix Sum
3553 Minimum Weighted Subgraph With the Required Paths II Array, Tree, Depth-First Search
3554 Find Category Recommendation Pairs Database
3559 Number of Ways to Assign Edge Weights II Array, Math, Dynamic Programming, Tree, Depth-First Search
3562 Maximum Profit from Trading Stocks with Discounts Array, Dynamic Programming, Tree, Depth-First Search
3563 Lexicographically Smallest String After Adjacent Removals String, Dynamic Programming
3569 Maximize Count of Distinct Primes After Split Array, Math, Segment Tree, Number Theory
3574 Maximize Subarray GCD Score Array, Math, Enumeration, Number Theory
3575 Maximum Good Subtree Score Array, Dynamic Programming, Bit Manipulation, Tree, Depth-First Search, Bitmask
3579 Minimum Steps to Convert String with Operations String, Dynamic Programming, Greedy
3585 Find Weighted Median Node in Tree Array, Binary Search, Dynamic Programming, Tree, Depth-First Search
3590 Kth Smallest Path XOR Sum Array, Tree, Depth-First Search, Ordered Set
3594 Minimum Time to Transport All Individuals Array, Dynamic Programming, Bit Manipulation, Graph, Heap (Priority Queue), Shortest Path, Bitmask
3600 Maximize Spanning Tree Stability with Upgrades Binary Search, Greedy, Union Find, Graph, Minimum Spanning Tree
3605 Minimum Stability Factor of Array Array, Math, Binary Search, Greedy, Segment Tree, Number Theory
3609 Minimum Moves to Reach Target in Grid Math
3614 Process String with Special Operations II String, Simulation
3615 Longest Palindromic Path in Graph String, Dynamic Programming, Bit Manipulation, Graph, Bitmask
3617 Find Students with Study Spiral Pattern -
3620 Network Recovery Pathways Array, Binary Search, Dynamic Programming, Graph, Topological Sort, Heap (Priority Queue), Shortest Path
3621 Number of Integers With Popcount-Depth Equal to K I Math, Dynamic Programming, Combinatorics
3624 Number of Integers With Popcount-Depth Equal to K II Array, Segment Tree
3625 Count Number of Trapezoids II Array, Hash Table, Math, Geometry
3630 Partition Array for Maximum XOR and AND Array, Math, Greedy, Enumeration
3636 Threshold Majority Queries -
3640 Trionic Array II -