There are three typical ways of recursively traversing a binary tree. In each of these, the left sub-trees & right sub-trees are visited recursively and the distinguishing feature is when the element in the root is visited or processed.

Program, Program3 and Program 4 illustrated the inorder, preorder and postorder traversals of a Binary tree.

Program : Inorder traversal of a binary tree

struct NODE *left;

int value;     /* can take any data type */

struct NODE *right;

};

inorder(struct NODE *curr)

{

if(curr->left != NULL)

inorder(curr->left);

printf("%d", curr->value);

if(curr->right != NULL)

inorder(curr->right);

}