if (the tree is not empty) { Do (recursively) an in-order traversal of the left sub-tree of the root ; Visit the root node ; Do (recursively) an in-order traversal of the right sub-tree of the root ; }
if (the tree is not empty) { Visit the root node ; Do (recursively) a pre-order traversal of the left sub-tree of the root ; Do (recursively) a pre-order traversal of the right sub-tree of the root ; }
if (the tree is not empty) { Do (recursively) a post-order traversal of the left sub-tree of the root ; Do (recursively) a post-order traversal of the right sub-tree of the root ; Visit the root node ; }