1-binary_tree_insert_left.c

#include "binary_trees.h"

/**
* binary_tree_insert_left - inserts a node as the left-child of another node
* @parent: pointer to the node to insert the left-child in
* @value: the value to store in the new node
* Return: pointer to the created node, or NULL on failure or if parent is NULL
*/
#include "binary_trees.h"
/**
 * binary_tree_insert_left - add a node in the left of the parent
 * if it exists it move down one level and add the new node first
 * @parent: parent of the specified node
 * @value: value of the node
 * Return: NULL if it fails or the new node
 */
binary_tree_t *binary_tree_insert_left(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);
	}
	if (parent->left != NULL)
	{
		new_node->left = parent->left;
		parent->left->parent = new_node;
	}
	parent->left = new_node;
	return (new_node);
}