Question

Implement the function for the prototype below. Document your code. You do not have access to authors helper functions, only the binary_tree_node class.

template size_t count(binary_tree_node * root_ptr, Item value)

// Precondition: root_ptr is the root pointer of a binary tree (which may be empty).

// Postcondition: The number of nodes that contain value in the tree is returned.

Answer 1

size_t count(binary_tree_node * root_ptr, Item value)

{

    // if the current subtree is empty

    if( !root_ptr )

        return 0;

   

    // if the current node has the value 'value'

    if( root_ptr->data == value )

        // recursively find the number of nodes in left and right subtree

        return 1 + count( root_ptr->left, value ) + count( root_ptr->right, value );

    else

        // recursively find the number of nodes in left and right subtree

        return count( root_ptr->left, value ) + count( root_ptr->right, value );

}