Second time

1. String abbreviation

2. 139 Maximum Path Sum Binary Tree II

3. 639 Max Path Sum From Leaf To Root

4. 141 Binary Tree Path Sum To Target III

5. 140 Maximum Path Sum Binary Tree III

6. 523 Flatten Binary Tree to Linked List

7. 213 Reconstruct Binary Tree With Preorder And Inorder

Cross Training plan II

1. 135 Closest Number In Binary Search Tree

2. 89 Array Hopper II