REPLACE WITH SUM OF GREATER NODES : Question unclear

#1

If the inorder traversal of bst is given, there are many bst structurally possible. Please explain the question.

#2

Basically, by default, if you look at the inorder traversal of any tree, it will always give u a sorted array only, so u need to use the concept of building tree using sorted array, thus u will use the concept of mid-point and check,
int mid=(start+end)/2;
node *root=new node(ar[mid]);
root->left=arr2BST(ar,start,mid-1);
root->right=arr2BST(ar,mid+1,end);
based on this recursive approach, you tree will be build on easily.