binary search:please tell me whats wrong here - error-handling

Question

I tried binary tree data structure but found it to be not working and giving an error. Please correct my code. Thanks!
It gives warning but with the inputs in main it stops running .
#include<stdlib.h>
#include<stdio.h>
typedef struct
{
int item;
struct node * leftc;
struct node * rightc;
}node;
void create(int key, node **tree )
{
if(*tree ==0)
{
(*tree)= (node *)malloc(sizeof(node *));
(*tree)->item=key;
(*tree)->leftc=((*tree)->rightc)=NULL;
}
else
{
if(key >= (*tree)->item )
{
create(key, &((*tree)->rightc));
}
else if(key<(*tree)->item)
{
create(key, &((*tree)->leftc));
}
}
}
node * search(int key, node * tree)
{
if(tree !=NULL)
{
if(key == tree->item)
return tree;
else if(key > tree->item)
search(key, tree->rightc);
else
search(key, tree->leftc);
}
return NULL;
}
void cut(node * tree)
{
if(tree != NULL)
{
cut(tree->leftc);
cut(tree->rightc);
free(tree);
}
}
void print_preorder(node * tree)
{
if (tree) {
printf("%d\n",tree->item);
print_preorder(tree->leftc);
print_preorder(tree->rightc);
}
}
int main()
{
node * root=NULL;
create(9,&root);
create(16,&root);
create(24,&root);
create(6,&root);
return 0;
}

Answer 1

Change
typedef struct
{
int item;
struct node * leftc;
struct node * rightc;
}node;
to
typedef struct node
{
int item;
struct node * leftc;
struct node * rightc;
}node;
Within your structure you refer to 'struct node' so you need the name in order for it to properly reference itself. Of course, after the typedef then you can just refer to it as node.
The test program compiled and ran fine with the code given otherwise.

Answer 2

I know this doesn't answer your question about the error, but I noticed a major problem with your search() function. You only return the node you're looking for if it's the first one that is put into the function. The recursive calls to search() do not return anything. The function should look something like this:
node * search(int key, node * tree)
{
if (tree !=NULL)
{
if (key == tree->item) {
return tree;
} else if (key > tree->item) {
return search(key, tree->rightc);
} else if (key < tree->item) {
return search(key, tree->leftc);
}
}
return NULL;
}
Also, in your create() function, did you mean to check if (*tree == NULL) instead of if (*tree == 0)?