| 1227 | Airplane Seat Assignment Probability | MathDynamic ProgrammingBrainteaser+1 | Medium |
| 1232 | Check If It Is a Straight Line | ArrayMathGeometry | Easy |
| 1233 | Remove Sub-Folders from the Filesystem | ArrayStringDepth-First Search+1 | Medium |
| 1234 | Replace the Substring for Balanced String | StringSliding Window | Medium |
| 1235 | Maximum Profit in Job Scheduling | ArrayBinary SearchDynamic Programming+1 | Hard |
| 1237 | Find Positive Integer Solution for a Given Equation | MathTwo PointersBinary Search+1 | Medium |
| 1238 | Circular Permutation in Binary Representation | MathBacktrackingBit Manipulation | Medium |
| 1239 | Maximum Length of a Concatenated String with Unique Characters | ArrayStringBacktracking+1 | Medium |
| 1240 | Tiling a Rectangle with the Fewest Squares | Backtracking | Hard |
| 1247 | Minimum Swaps to Make Strings Equal | MathStringGreedy | Medium |
| 1248 | Count Number of Nice Subarrays | ArrayHash TableMath+2 | Medium |
| 1249 | Minimum Remove to Make Valid Parentheses | StringStack | Medium |
| 1250 | Check If It Is a Good Array | ArrayMathNumber Theory | Hard |
| 1251 | Average Selling Price | Database | Easy |
| 1252 | Cells with Odd Values in a Matrix | ArrayMathSimulation | Easy |
| 1253 | Reconstruct a 2-Row Binary Matrix | ArrayGreedyMatrix | Medium |
| 1254 | Number of Closed Islands | ArrayDepth-First SearchBreadth-First Search+2 | Medium |
| 1255 | Maximum Score Words Formed by Letters | ArrayStringDynamic Programming+3 | Hard |
| 1260 | Shift 2D Grid | ArrayMatrixSimulation | Easy |
| 1261 | Find Elements in a Contaminated Binary Tree | Hash TableTreeDepth-First Search+3 | Medium |
| 1262 | Greatest Sum Divisible by Three | ArrayDynamic ProgrammingGreedy+1 | Medium |
| 1263 | Minimum Moves to Move a Box to Their Target Location | ArrayBreadth-First SearchHeap (Priority Queue)+1 | Hard |
| 1266 | Minimum Time Visiting All Points | ArrayMathGeometry | Easy |
| 1267 | Count Servers that Communicate | ArrayDepth-First SearchBreadth-First Search+3 | Medium |
| 1268 | Search Suggestions System | ArrayStringBinary Search+3 | Medium |
| 1269 | Number of Ways to Stay in the Same Place After Some Steps | Dynamic Programming | Hard |
| 1275 | Find Winner on a Tic Tac Toe Game | ArrayHash TableMatrix+1 | Easy |
| 1276 | Number of Burgers with No Waste of Ingredients | Math | Medium |
| 1277 | Count Square Submatrices with All Ones | ArrayDynamic ProgrammingMatrix | Medium |
| 1278 | Palindrome Partitioning III | StringDynamic Programming | Hard |
| 1280 | Students and Examinations | Database | Easy |
| 1281 | Subtract the Product and Sum of Digits of an Integer | Math | Easy |
| 1282 | Group the People Given the Group Size They Belong To | ArrayHash TableGreedy | Medium |
| 1283 | Find the Smallest Divisor Given a Threshold | ArrayBinary Search | Medium |
| 1284 | Minimum Number of Flips to Convert Binary Matrix to Zero Matrix | ArrayHash TableBit Manipulation+2 | Hard |
| 1286 | Iterator for Combination | StringBacktrackingDesign+1 | Medium |
| 1287 | Element Appearing More Than 25% In Sorted Array | Array | Easy |
| 1288 | Remove Covered Intervals | ArraySorting | Medium |
| 1289 | Minimum Falling Path Sum II | ArrayDynamic ProgrammingMatrix | Hard |
| 1290 | Convert Binary Number in a Linked List to Integer | Linked ListMath | Easy |
| 1291 | Sequential Digits | Enumeration | Medium |
| 1292 | Maximum Side Length of a Square with Sum Less than or Equal to Threshold | ArrayBinary SearchMatrix+1 | Medium |
| 1293 | Shortest Path in a Grid with Obstacles Elimination | ArrayBreadth-First SearchMatrix | Hard |
| 1295 | Find Numbers with Even Number of Digits | ArrayMath | Easy |
| 1296 | Divide Array in Sets of K Consecutive Numbers | ArrayHash TableGreedy+1 | Medium |
| 1297 | Maximum Number of Occurrences of a Substring | Hash TableStringSliding Window | Medium |
| 1298 | Maximum Candies You Can Get from Boxes | ArrayBreadth-First SearchGraph | Hard |
| 1299 | Replace Elements with Greatest Element on Right Side | Array | Easy |
| 1300 | Sum of Mutated Array Closest to Target | ArrayBinary SearchSorting | Medium |
| 1301 | Number of Paths with Max Score | ArrayDynamic ProgrammingMatrix | Hard |