| 1591 | Strange Printer II | Hard | 2291 | arraygraphtopological-sort+1 |
| 1606 | Find Servers That Handled Most Number of Requests | Hard | 2276 | arrayheap-priority-queuesimulation+1 |
| 1622 | Fancy Sequence | Hard | 2476 | mathdesignsegment-tree |
| 1627 | Graph Connectivity With Threshold | Hard | 2221 | arraymathunion-find+1 |
| 1632 | Rank Transform of a Matrix | Hard | 2530 | arrayunion-findgraph+3 |
| 1639 | Number of Ways to Form a Target String Given a Dictionary | Hard | 2082 | arraystringdynamic-programming |
| 1649 | Create Sorted Array through Instructions | Hard | 2208 | arraybinary-searchdivide-and-conquer+4 |
| 1655 | Distribute Repeating Integers | Hard | 2307 | arrayhash-tabledynamic-programming+4 |
| 1675 | Minimize Deviation in Array | Hard | 2091 | arraygreedyheap-priority-queue+1 |
| 1687 | Delivering Boxes from Storage to Ports | Hard | 2610 | arraydynamic-programmingsegment-tree+4 |
| 1697 | Checking Existence of Edge Length Limited Paths | Hard | 2300 | arraytwo-pointersunion-find+2 |
| 1707 | Maximum XOR With an Element From Array | Hard | 2359 | arraybit-manipulationtrie |
| 1719 | Number Of Ways To Reconstruct A Tree | Hard | 3018 | arrayhash-tabletree+2 |
| 1728 | Cat and Mouse II | Hard | 2849 | arraymathdynamic-programming+5 |
| 1735 | Count Ways to Make Array With Product | Hard | 2500 | arraymathdynamic-programming+2 |
| 1776 | Car Fleet II | Hard | 1863 | arraymathstack+2 |
| 1782 | Count Pairs Of Nodes | Hard | 2457 | arrayhash-tabletwo-pointers+4 |
| 1799 | Maximize Score After N Operations | Hard | 2073 | arraymathdynamic-programming+4 |
| 1808 | Maximize Number of Nice Divisors | Hard | 2070 | mathrecursionnumber-theory |
| 1819 | Number of Different Subsequences GCDs | Hard | 2540 | arraymathcounting+1 |
| 1825 | Finding MK Average | Hard | 2396 | designqueueheap-priority-queue+2 |
| 1830 | Minimum Number of Operations to Make String Sorted | Hard | 2620 | hash-tablemathstring+2 |
| 1851 | Minimum Interval to Include Each Query | Hard | 2286 | arraybinary-searchsorting+1 |
| 1857 | Largest Color Value in a Directed Graph | Hard | 2313 | hash-tablestringdynamic-programming+4 |
| 1866 | Number of Ways to Rearrange Sticks With K Sticks Visible | Hard | 2333 | mathdynamic-programmingcombinatorics |
| 1912 | Design Movie Rental System | Hard | 2182 | arrayhash-tabledesign+2 |
| 1916 | Count Ways to Build Rooms in an Ant Colony | Hard | 2486 | arraymathdynamic-programming+5 |
| 1944 | Number of Visible People in a Queue | Hard | 2105 | arraystackmonotonic-stack |
| 1964 | Find the Longest Valid Obstacle Course at Each Position | Hard | 1933 | arraybinary-searchbinary-indexed-tree |
| 1994 | The Number of Good Subsets | Hard | 2465 | arrayhash-tablemath+5 |
| 1998 | GCD Sort of an Array | Hard | 2429 | arraymathunion-find+2 |
| 2014 | Longest Subsequence Repeated k Times | Hard | 2558 | hash-tabletwo-pointersstring+3 |
| 2045 | Second Minimum Time to Reach Destination | Hard | 2202 | breadth-first-searchgraphshortest-path |
| 2050 | Parallel Courses III | Hard | 2084 | arraydynamic-programminggraph+1 |
| 2056 | Number of Valid Move Combinations On Chessboard | Hard | 2611 | arraystringbacktracking+1 |
| 2065 | Maximum Path Quality of a Graph | Hard | 2178 | arraybacktrackinggraph |
| 2071 | Maximum Number of Tasks You Can Assign | Hard | 2648 | arraytwo-pointersbinary-search+4 |
| 2076 | Process Restricted Friend Requests | Hard | 2131 | union-findgraph |
| 2092 | Find All People With Secret | Hard | 2004 | depth-first-searchbreadth-first-searchunion-find+2 |
| 2102 | Sequentially Ordinal Rank Tracker | Hard | 2159 | designheap-priority-queuedata-stream+1 |
| 2127 | Maximum Employees to Be Invited to a Meeting | Hard | 2449 | arraydynamic-programmingdepth-first-search+2 |
| 2163 | Minimum Difference in Sums After Removal of Elements | Hard | 2175 | arraydynamic-programmingheap-priority-queue |
| 2179 | Count Good Triplets in an Array | Hard | 2272 | arraybinary-searchdivide-and-conquer+4 |
| 2183 | Count Array Pairs Divisible by K | Hard | 2246 | arrayhash-tablemath+2 |
| 2203 | Minimum Weighted Subgraph With the Required Paths | Hard | 2364 | graphheap-priority-queueshortest-path |
| 2218 | Maximum Value of K Coins From Piles | Hard | 2158 | arraydynamic-programmingprefix-sum |
| 2227 | Encrypt and Decrypt Strings | Hard | 1945 | arrayhash-tablestring+2 |
| 2276 | Count Integers in Intervals | Hard | 2222 | designsegment-treeordered-set |
| 2282 | Number of People That Can Be Seen in a Grid | Hard | 1980 | arraystackmatrix+2 |
| 2286 | Booking Concert Tickets in Groups | Hard | 2470 | binary-searchdesignbinary-indexed-tree+1 |