910 
Smallest Range II 
Medium 

919 
Complete Binary Tree Inserter 
Medium 
Tree

921 
Minimum Add to Make Parentheses Valid 
Medium 

927 
Three Equal Parts 
Hard 

928 
Minimize Malware Spread II 
Hard 

936 
Stamping The Sequence 
Hard 

937 
Reorder Data in Log Files 
Easy 

938 
Range Sum of BST 
Easy 
Tree

Recursion

944 
Delete Columns to Make Sorted 
Easy 

948 
Bag of Tokens 
Medium 

951 
Flip Equivalent Binary Trees 
Medium 
Tree

955 
Delete Columns to Make Sorted II 
Medium 

957 
Prison Cells After N Days 
Medium 

958 
Check Completeness of a Binary Tree 
Medium 
Tree

959 
Regions Cut By Slashes 
Medium 

965 
Univalued Binary Tree 
Easy 
Tree

968 
Binary Tree Cameras 
Hard 
Dynamic Programming

Tree

Depthfirst Search

971 
Flip Binary Tree To Match Preorder Traversal 
Medium 
Tree

Depthfirst Search

973 
K Closest Points to Origin 
Medium 

979 
Distribute Coins in Binary Tree 
Medium 
Tree

Depthfirst Search

984 
String Without AAA or BBB 
Medium 

987 
Vertical Order Traversal of a Binary Tree 
Hard 
Hash Table 
Tree

988 
Smallest String Starting From Leaf 
Medium 
Tree

Depthfirst Search

990 
Satisfiability of Equality Equations 
Medium 

991 
Broken Calculator 
Medium 

993 
Cousins in Binary Tree 
Easy 
Tree

Breadthfirst Search

996 
Number of Squareful Arrays 
Hard 

997 
Find the Town Judge 
Easy 

998 
Maximum Binary Tree II 
Medium 
Tree
