BST Traversal

Given a Binary Search Tree, Traverse the tree in Preorder, Postorder, and inorder traversal.

Consider the following Binary Tree

Binary Search Tree
                10
              /   \
            5       18
          /   \       \
        1       7      21

Preorder Traversal

When you traverse a tree in root->left->right fashion, it is called a preorder traversal. In the above example, the preorder traversal of the tree will be

10 5 1 7 18 21

Postorder Traversal

Here, the traversal order will be left->right->root. That is, left subtree is traversed first, then the the right subtree is traversed, and finally the root value is printed.

The postorder traversal of the above tree will be

1 7 5 21 20 18 10 

Inorder Traversal

Here, the traversal order will be left->root->right. That is, left subtree is traversed first, then the root value is printed, and finally the right subtree is printed.

The postorder traversal of the above tree will be

1 5 7 10 18 21 

The inorder traversal of a BST always returns value in a sorted order.

Constraints

0 <= N <=1000;
N = Node value in a Binary Tree.