| 899 | Orderly Queue | Hard |
| 902 | Numbers At Most N Given Digit Set | Hard |
| 903 | Valid Permutations for DI Sequence | Hard |
| 906 | Super Palindromes | Hard |
| 913 | Cat and Mouse | Hard |
| 920 | Number of Music Playlists | Hard |
| 924 | Minimize Malware Spread | Hard |
| 927 | Three Equal Parts | Hard |
| 928 | Minimize Malware Spread II | Hard |
| 936 | Stamping The Sequence | Hard |
| 940 | Distinct Subsequences II | Hard |
| 943 | Find the Shortest Superstring | Hard |
| 964 | Least Operators to Express Number | Hard |
| 968 | Binary Tree Cameras | Hard |
| 972 | Equal Rational Numbers | Hard |
| 975 | Odd Even Jump | Hard |
| 980 | Unique Paths III | Hard |
| 982 | Triples with Bitwise AND Equal To Zero | Hard |
| 987 | Vertical Order Traversal of a Binary Tree | Hard |
| 989 | Largest Component Size by Common Factor | Hard |
| 992 | Subarrays with K Different Integers | Hard |
| 993 | Tallest Billboard | Hard |
| 995 | Minimum Number of K Consecutive Bit Flips | Hard |
| 996 | Number of Squareful Arrays | Hard |
| 1000 | Minimum Cost to Merge Stones | Hard |
| 1000 | Delete Columns to Make Sorted III | Hard |
| 1001 | Grid Illumination | Hard |
| 1012 | Numbers With Repeated Digits | Hard |
| 1028 | Recover a Tree From Preorder Traversal | Hard |
| 1032 | Stream of Characters | Hard |