| 1130 | Minimum Cost Tree From Leaf Values | Medium | 1759 | arraydynamic-programmingstack+2 |
| 1140 | Stone Game II | Medium | 2035 | arraymathdynamic-programming+2 |
| 1143 | Longest Common Subsequence | Medium | 1727 | stringdynamic-programming |
| 1161 | Maximum Level Sum of a Binary Tree | Medium | 1388 | treebfsbinary-tree |
| 1162 | As Far from Land as Possible | Medium | 1666 | arraydynamic-programmingbreadth-first-search+1 |
| 1201 | Ugly Number III | Medium | 2039 | mathbinary-searchcombinatorics+1 |
| 1209 | Remove All Adjacent Duplicates in String II | Medium | 1542 | stringstack |
| 1229 | Meeting Scheduler | Medium | 1423 | arraytwo-pointerssorting |
| 1233 | Remove Sub-Folders from the Filesystem | Medium | 1505 | arraystringtrie |
| 1234 | Replace the Substring for Balanced String | Medium | 1878 | stringsliding-windowtwo-pointers |
| 1239 | Maximum Length of a Concatenated String with Unique Characters | Medium | 1791 | arraystringbacktracking+1 |
| 1249 | Minimum Remove to Make Valid Parentheses | Medium | 1657 | stringstack |
| 1254 | Number of Closed Islands | Medium | 1659 | arraydepth-first-searchbreadth-first-search+2 |
| 1267 | Count Servers that Communicate | Medium | 1375 | arraydepth-first-searchbreadth-first-search+3 |
| 1268 | Search Suggestions System | Medium | 1573 | stringtriebinary-search+1 |
| 1272 | Remove Interval | Medium | 1535 | array |
| 1283 | Find the Smallest Divisor Given a Threshold | Medium | 1541 | arraybinary-search |
| 1286 | Iterator for Combination | Medium | 1591 | stringbacktrackingdesign+1 |
| 1288 | Remove Covered Intervals | Medium | 1375 | arraygreedysorting |
| 1305 | All Elements in Two Binary Search Trees | Medium | 1260 | treedepth-first-searchbinary-search-tree+2 |
| 1318 | Minimum Flips to Make a OR b Equal to c | Medium | 1476 | bit-manipulationmath |
| 1319 | Number of Operations to Make Network Connected | Medium | 1633 | depth-first-searchbreadth-first-searchunion-find+1 |
| 1334 | Find the City With the Smallest Number of Neighbors at a Threshold Distance | Medium | 1855 | dynamic-programminggraphshortest-path |
| 1343 | Number of Sub-arrays of Size K and Average Greater Than or Equal to Threshold | Medium | 1317 | arraysliding-window |
| 1348 | Tweet Counts Per Frequency | Medium | 2037 | hash-tablestringbinary-search+3 |
| 1352 | Product of the Last K Numbers | Medium | 1474 | arraymathdesign+2 |
| 1353 | Maximum Number of Events That Can Be Attended | Medium | 1786 | arraygreedysorting+1 |
| 1361 | Validate Binary Tree Nodes | Medium | 1465 | treedepth-first-searchbreadth-first-search+3 |
| 1372 | Longest ZigZag Path in a Binary Tree | Medium | 1713 | dynamic-programmingtreedepth-first-search+1 |
| 1376 | Time Needed to Inform All Employees | Medium | 1561 | treedepth-first-searchbreadth-first-search |
| 1382 | Balance a Binary Search Tree | Medium | 1541 | divide-and-conquergreedytree+3 |
| 1395 | Count Number of Teams | Medium | 1344 | arraydynamic-programmingbinary-indexed-tree+1 |
| 1396 | Design Underground System | Medium | 1465 | hash-tablestringdesign |
| 1405 | Longest Happy String | Medium | 1821 | stringgreedyheap-priority-queue |
| 1409 | Queries on a Permutation With Key | Medium | 1335 | arraybinary-indexed-treesimulation |
| 1423 | Maximum Points You Can Obtain from Cards | Medium | 1574 | arraysliding-windowprefix-sum |
| 1438 | Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit | Medium | 1672 | arrayqueuesliding-window+3 |
| 1443 | Minimum Time to Collect All Apples in a Tree | Medium | 1683 | hash-tabletreedepth-first-search+1 |
| 1448 | Count Good Nodes in Binary Tree | Medium | 1438 | treedepth-first-searchbreadth-first-search+1 |
| 1456 | Maximum Number of Vowels in a Substring of Given Length | Medium | 1263 | stringsliding-window |
| 1461 | Check If a String Contains All Binary Codes of Size K | Medium | 1504 | hash-tablestringbit-manipulation+2 |
| 1462 | Course Schedule IV | Medium | 1693 | depth-first-searchbreadth-first-searchgraph+1 |
| 1466 | Reorder Routes to Make All Paths Lead to the City Zero | Medium | 1634 | graphdfsbfs |
| 1472 | Design Browser History | Medium | 1454 | arraylinked-liststack+3 |
| 1493 | Longest Subarray of 1's After Deleting One Element | Medium | 1423 | sliding-windowarraydynamic-programming |
| 1498 | Number of Subsequences That Satisfy the Given Sum Condition | Medium | 2276 | arraytwo-pointersbinary-search+1 |
| 1514 | Path with Maximum Probability | Medium | 1846 | arraygraphheap-priority-queue+1 |
| 1545 | Find Kth Bit in Nth Binary String | Medium | 1479 | stringrecursionsimulation |
| 1557 | Minimum Number of Vertices to Reach All Nodes | Medium | 1512 | graph |
| 1584 | Min Cost to Connect All Points | Medium | 1605 | arrayunion-findgraph+1 |