Hard LeetCode Problems: Page 2 of 4

Problems 201 to 400 of the 661 Hard-rated problems in this library, continuing the list on the Hard hub.

Page 2 of 4

Hard problems, page 2
No.	Problem	Topics
1293	Shortest Path in a Grid with Obstacles Elimination	Breadth-First Search, Array, Matrix
1298	Maximum Candies You Can Get from Boxes	Breadth-First Search, Graph, Array
1301	Number of Paths with Max Score	Array, Dynamic Programming, Matrix
1307	Verbal Arithmetic Puzzle	Array, Math, String +1
1312	Minimum Insertion Steps to Make a String Palindrome	String, Dynamic Programming
1316	Distinct Echo Substrings	Trie, String, Hash Function +1
1320	Minimum Distance to Type a Word Using Two Fingers	String, Dynamic Programming
1326	Minimum Number of Taps to Open to Water a Garden	Greedy, Array, Dynamic Programming
1330	Reverse Subarray To Maximize Array Value	Greedy, Array, Math
1335	Minimum Difficulty of a Job Schedule	Array, Dynamic Programming
1340	Jump Game V	Array, Dynamic Programming, Sorting
1345	Jump Game IV	Breadth-First Search, Array, Hash Table
1349	Maximum Students Taking Exam	Bit Manipulation, Array, Dynamic Programming +2
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	Greedy, Array, Math +2
1368	Minimum Cost to Make at Least One Valid Path in a Grid	Breadth-First Search, Graph, Array +3
1373	Maximum Sum BST in Binary Tree	Tree, Depth-First Search, Binary Search Tree +2
1377	Frog Position After T Seconds	Tree, Depth-First Search, Breadth-First Search +1
1383	Maximum Performance of a Team	Greedy, Array, Sorting +1
1388	Pizza With 3n Slices	Greedy, Array, Dynamic Programming +1
1392	Longest Happy Prefix	String, String Matching, Hash Function +1
1402	Reducing Dishes	Greedy, Array, Dynamic Programming +1
1406	Stone Game III	Array, Math, Dynamic Programming +1
1411	Number of Ways to Paint N × 3 Grid	Dynamic Programming
1420	Build Array Where You Can Find The Maximum Exactly K Comparisons	Dynamic Programming, Prefix Sum
1425	Constrained Subsequence Sum	Queue, Array, Dynamic Programming +3
1434	Number of Ways to Wear Different Hats to Each Other	Bit Manipulation, Array, Dynamic Programming +1
1439	Find the Kth Smallest Sum of a Matrix With Sorted Rows	Array, Binary Search, Matrix +1
1444	Number of Ways of Cutting a Pizza	Memoization, Array, Dynamic Programming +2
1449	Form Largest Integer With Digits That Add up to Target	Array, Dynamic Programming
1453	Maximum Number of Darts Inside of a Circular Dartboard	Geometry, Array, Math
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 +3
1473	Paint House III	Array, Dynamic Programming
1478	Allocate Mailboxes	Array, Math, Dynamic Programming +1
1483	Kth Ancestor of a Tree Node	Bit Manipulation, Tree, Depth-First Search +4
1489	Find Critical and Pseudo-Critical Edges in Minimum Spanning Tree	Union Find, Graph, Minimum Spanning Tree +2
1494	Parallel Courses II	Bit Manipulation, Graph, Dynamic Programming +1
1499	Max Value of Equation	Queue, Array, Sliding Window +2
1505	Minimum Possible Integer After at Most K Adjacent Swaps On Digits	Greedy, Binary Indexed Tree, Segment Tree +1
1510	Stone Game IV	Math, Dynamic Programming, Game Theory
1515	Best Position for a Service Centre	Geometry, Array, Math +1
1521	Find a Value of a Mysterious Function Closest to Target	Bit Manipulation, Segment Tree, Array +1
1526	Minimum Number of Increments on Subarrays to Form a Target Array	Stack, Greedy, Array +2
1531	String Compression II	String, Dynamic Programming
1537	Get the Maximum Score	Greedy, Array, Two Pointers +1
1542	Find Longest Awesome Substring	Bit Manipulation, Hash Table, String
1547	Minimum Cost to Cut a Stick	Array, Dynamic Programming, Sorting
1553	Minimum Number of Days to Eat N Oranges	Memoization, Dynamic Programming
1563	Stone Game V	Array, Math, Dynamic Programming +1
1568	Minimum Number of Days to Disconnect Island	Depth-First Search, Breadth-First Search, Array +2
1569	Number of Ways to Reorder Array to Get Same BST	Tree, Union Find, Binary Search Tree +7
1575	Count All Possible Routes	Memoization, Array, Dynamic Programming
1579	Remove Max Number of Edges to Keep Graph Fully Traversable	Union Find, Graph
1585	Check If String Is Transformable With Substring Sort Operations	Greedy, String, Sorting
1595	Minimum Cost to Connect Two Groups of Points	Bit Manipulation, Array, Dynamic Programming +2
1601	Maximum Number of Achievable Transfer Requests	Bit Manipulation, Array, Backtracking +1
1606	Find Servers That Handled Most Number of Requests	Array, Ordered Set, Simulation +1
1610	Maximum Number of Visible Points	Geometry, Array, Math +2
1611	Minimum One Bit Operations to Make Integers Zero	Bit Manipulation, Memoization, Dynamic Programming
1617	Count Subtrees With Max Distance Between Cities	Bit Manipulation, Tree, Dynamic Programming +2
1622	Fancy Sequence	Design, Segment Tree, Math
1627	Graph Connectivity With Threshold	Union Find, Array, Math +1
1632	Rank Transform of a Matrix	Union Find, Graph, Topological Sort +3
1639	Number of Ways to Form a Target String Given a Dictionary	Array, String, Dynamic Programming
1643	Kth Smallest Instructions	Array, Math, Dynamic Programming +1
1649	Create Sorted Array through Instructions	Binary Indexed Tree, Segment Tree, Array +4
1655	Distribute Repeating Integers	Bit Manipulation, Array, Dynamic Programming +2
1659	Maximize Grid Happiness	Bit Manipulation, Memoization, Dynamic Programming +1
1665	Minimum Initial Energy to Finish Tasks	Greedy, Array, Sorting
1671	Minimum Number of Removals to Make Mountain Array	Greedy, Array, Binary Search +1
1675	Minimize Deviation in Array	Greedy, Array, Ordered Set +1
1681	Minimum Incompatibility	Bit Manipulation, Array, Dynamic Programming +1
1687	Delivering Boxes from Storage to Ports	Segment Tree, Queue, Array +4
1691	Maximum Height by Stacking Cuboids	Array, Dynamic Programming, Sorting
1697	Checking Existence of Edge Length Limited Paths	Union Find, Graph, Array +2
1703	Minimum Adjacent Swaps for K Consecutive Ones	Greedy, Array, Prefix Sum +1
1707	Maximum XOR With an Element From Array	Bit Manipulation, Trie, Array
1713	Minimum Operations to Make a Subsequence	Greedy, Array, Hash Table +1
1719	Number Of Ways To Reconstruct A Tree	Tree, Graph
1723	Find Minimum Time to Finish All Jobs	Bit Manipulation, Array, Dynamic Programming +2
1728	Cat and Mouse II	Graph, Topological Sort, Memoization +5
1735	Count Ways to Make Array With Product	Array, Math, Dynamic Programming +2
1739	Building Boxes	Greedy, Math, Binary Search
1745	Palindrome Partitioning IV	String, Dynamic Programming
1751	Maximum Number of Events That Can Be Attended II	Array, Binary Search, Dynamic Programming +1
1755	Closest Subsequence Sum	Bit Manipulation, Array, Two Pointers +3
1761	Minimum Degree of a Connected Trio in a Graph	Graph, Enumeration
1766	Tree of Coprimes	Tree, Depth-First Search, Array +2
1770	Maximum Score from Performing Multiplication Operations	Array, Dynamic Programming
1771	Maximize Palindrome Length From Subsequences	String, Dynamic Programming
1776	Car Fleet II	Stack, Array, Math +2
1782	Count Pairs Of Nodes	Graph, Array, Hash Table +4
1787	Make the XOR of All Segments Equal to Zero	Bit Manipulation, Array, Dynamic Programming
1793	Maximum Score of a Good Subarray	Stack, Array, Two Pointers +2
1799	Maximize Score After N Operations	Bit Manipulation, Array, Math +4
1803	Count Pairs With XOR in a Range	Bit Manipulation, Trie, Array
1808	Maximize Number of Nice Divisors	Recursion, Math, Number Theory
1815	Maximum Number of Groups Getting Fresh Donuts	Bit Manipulation, Memoization, Array +2
1819	Number of Different Subsequences GCDs	Array, Math, Counting +1
1825	Finding MK Average	Design, Queue, Data Stream +2
1830	Minimum Number of Operations to Make String Sorted	Math, String, Combinatorics
1835	Find XOR Sum of All Pairs Bitwise AND	Bit Manipulation, Array, Math
1840	Maximum Building Height	Array, Math, Sorting
1847	Closest Room	Array, Binary Search, Ordered Set +1
1851	Minimum Interval to Include Each Query	Array, Binary Search, Sorting +2
1857	Largest Color Value in a Directed Graph	Graph, Topological Sort, Memoization +3
1862	Sum of Floored Pairs	Array, Math, Binary Search +1
1866	Number of Ways to Rearrange Sticks With K Sticks Visible	Math, Dynamic Programming, Combinatorics
1872	Stone Game VIII	Array, Math, Dynamic Programming +2
1879	Minimum XOR Sum of Two Arrays	Bit Manipulation, Array, Dynamic Programming +1
1883	Minimum Skips to Arrive at Meeting On Time	Array, Dynamic Programming
1889	Minimum Space Wasted From Packaging	Array, Binary Search, Prefix Sum +1
1900	The Earliest and Latest Rounds Where Players Compete	Memoization, Dynamic Programming
1912	Design Movie Rental System	Design, Array, Hash Table +2
1916	Count Ways to Build Rooms in an Ant Colony	Tree, Graph, Topological Sort +3
1923	Longest Common Subpath	Array, Binary Search, Suffix Array +2
1928	Minimum Cost to Reach Destination in Time	Graph, Array, Dynamic Programming
1931	Painting a Grid With Three Different Colors	Dynamic Programming
1944	Number of Visible People in a Queue	Stack, Array, Monotonic Stack
1948	Delete Duplicate Folders in System	Trie, Array, Hash Table +2
1955	Count Number of Special Subsequences	Array, Dynamic Programming
1960	Maximum Product of the Length of Two Palindromic Substrings	String, Hash Function, Rolling Hash
1964	Find the Longest Valid Obstacle Course at Each Position	Binary Indexed Tree, Array, Binary Search
1970	Last Day Where You Can Still Cross	Depth-First Search, Breadth-First Search, Union Find +3
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	Bit Manipulation, Array, Hash Table +5
1998	GCD Sort of an Array	Union Find, Array, Math +2
2003	Smallest Missing Genetic Value in Each Subtree	Tree, Depth-First Search, Union Find +1
2009	Minimum Number of Operations to Make Array Continuous	Array, Hash Table, Binary Search +1
2014	Longest Subsequence Repeated k Times	Greedy, String, Backtracking +2
2019	The Score of Students Solving Math Expression	Stack, Memoization, Array +4
2025	Maximum Number of Ways to Partition an Array	Array, Hash Table, Counting +2
2035	Partition Array Into Two Arrays to Minimize Sum Difference	Bit Manipulation, Array, Two Pointers +4
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	Graph, Topological Sort, Array +1
2056	Number of Valid Move Combinations On Chessboard	Array, String, Backtracking +1
2060	Check if an Original String Exists Given Two Encoded Strings	String, Dynamic Programming
2065	Maximum Path Quality of a Graph	Graph, Array, Backtracking
2071	Maximum Number of Tasks You Can Assign	Greedy, Queue, Array +4
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 +2
2102	Sequentially Ordinal Rank Tracker	Design, Data Stream, Ordered Set +1
2106	Maximum Fruits Harvested After at Most K Steps	Array, Binary Search, Prefix Sum +1
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 +2
2127	Maximum Employees to Be Invited to a Meeting	Depth-First Search, Graph, Topological Sort
2132	Stamping the Grid	Greedy, Array, Matrix +1
2136	Earliest Possible Day of Full Bloom	Greedy, Array, Sorting
2141	Maximum Running Time of N Computers	Greedy, Array, Binary Search +1
2147	Number of Ways to Divide a Long Corridor	Math, String, Dynamic Programming
2151	Maximum Good People Based on Statements	Bit Manipulation, Array, Backtracking +1
2156	Find Substring With Given Hash Value	String, Sliding Window, Hash Function +1
2157	Groups of Strings	Bit Manipulation, Union Find, String
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	Bit Manipulation, Array, Dynamic Programming +1
2179	Count Good Triplets in an Array	Binary Indexed Tree, Segment Tree, Array +4
2188	Minimum Time to Finish the Race	Array, Dynamic Programming
2193	Minimum Number of Moves to Make Palindrome	Greedy, Binary Indexed Tree, Two Pointers +1
2197	Replace Non-Coprime Numbers in Array	Stack, Array, Math +1
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	Segment Tree, Array, String +1
2218	Maximum Value of K Coins From Piles	Array, Dynamic Programming, Prefix Sum
2227	Encrypt and Decrypt Strings	Design, Trie, Array +2
2234	Maximum Total Beauty of the Gardens	Greedy, Array, Two Pointers +4
2242	Maximum Score of a Node Sequence	Graph, Array, Enumeration +1
2246	Longest Path With Different Adjacent Characters	Tree, Depth-First Search, Graph +3
2251	Number of Flowers in Full Bloom	Array, Hash Table, Binary Search +3
2258	Escape the Spreading Fire	Breadth-First Search, Array, Binary Search +1
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	Stack, Array, Prefix Sum +1
2286	Booking Concert Tickets in Groups	Design, Binary Indexed Tree, Segment Tree +1
2290	Minimum Obstacle Removal to Reach Corner	Breadth-First Search, Graph, Array +3
2296	Design a Text Editor	Stack, Design, Linked List +3
2301	Match Substring After Replacement	Array, Hash Table, String +1
2302	Count Subarrays With Score Less Than K	Array, Binary Search, Prefix Sum +1
2306	Naming a Company	Bit Manipulation, Array, Hash Table +2
2312	Selling Pieces of Wood	Memoization, Array, Dynamic Programming
2318	Number of Distinct Roll Sequences	Memoization, Dynamic Programming
2321	Maximum Score Of Spliced Array	Array, Dynamic Programming
2322	Minimum Score After Removals on a Tree	Bit Manipulation, Tree, Depth-First Search +1
2328	Number of Increasing Paths in a Grid	Depth-First Search, Breadth-First Search, Graph +5
2334	Subarray With Elements Greater Than Varying Threshold	Stack, Union Find, Array +1
2338	Count the Number of Ideal Arrays	Math, Dynamic Programming, Combinatorics +1
2344	Minimum Deletions to Make Array Divisible	Array, Math, Number Theory +2
2350	Shortest Impossible Sequence of Rolls	Greedy, Array, Hash Table
2354	Number of Excellent Pairs	Bit Manipulation, Array, Hash Table +1

Problems with a complete Python solution are listed first, then by ascending problem number. Or go by technique instead: all LeetCode patterns.