2-binary_tree_insert_right.c

#include "binary_trees.h"

/**
 * binary_tree_insert_right - inserts a node as the right-child of another node
 *
 * @parent: a pointer to the node to insert the right-child in
 * @value: the value to store in the new node.
 *
 * if parent already has a right-child, the new node must take its place,
 * and the old right-child must be set as the right-child of the new node.
 *
 * Return: a pointer to the created node, or NULL on failure,
 * or if parent is NULL
 */
binary_tree_t *binary_tree_insert_right(binary_tree_t *parent, int value)
{
	binary_tree_t *new_node;

	if (parent == NULL)
		return (NULL);
	new_node = binary_tree_node(parent, value);
	if (new_node == NULL)
		return (NULL);

	new_node->right = parent->right;
	if (parent->right != NULL)
		parent->right->parent = new_node;
	parent->right = new_node;
	return (NULL);
}