C Programming

#include
#include
#include

struct tree
{
int te;
struct tree *lc;
struct tree *rc;
};
typedef struct tree node;
node *tree_ptr,*ptr;
node *create_tree(int te,node *tree_ptr);
void preorder_traversal(node *ptr);
void postorder_traversal(node *ptr);
void inorder_traversal(node *ptr);
void traversal(node *ptr);

void main()
{
clrscr();
int te,a,n,key_item;
char ch;
int key_element;
node *tree_ptr=NULL;
do
{
printf("\n\n Menue\n");
printf("===============================\n\n");
printf("1.(C)Create a tree by inserting node.\n");
printf("2.(P)Traverse tree in preorder.\n");
printf("3.(I)Traverse tree in preorder.\n");
printf("4.(O)Traverse tree in preorder.\n");
printf("5.(E)xit\n");
printf("\nEnter your choice:");
ch=getche();
if(ch=='C'||ch=='c')
{
printf("\n\nHow many number do you want to enter?:");
scanf("%d",&n);
for(a=0;ate=te;
tree_ptr->lc=NULL;
tree_ptr->rc=NULL;
return (tree_ptr);
}

if(te<>te)
tree_ptr->lc=create_tree(te,tree_ptr->lc);

if(te> tree_ptr->te)
tree_ptr->rc=create_tree(te,tree_ptr->rc);

return (tree_ptr);

}

void preorder_traversal(node *ptr)
{
if(ptr)
{
printf("%d ",ptr->te);
preorder_traversal(ptr->lc);
preorder_traversal(ptr->rc);
}
}


void postorder_traversal(node *ptr)
{
if(ptr)
{
postorder_traversal(ptr->lc);
postorder_traversal(ptr->rc);
printf("%d ",ptr->te);
}
}

void inorder_traversal(node *ptr)
{
if(ptr)
{
inorder_traversal(ptr->lc);
printf("%d ",ptr->te);
inorder_traversal(ptr->rc);
}
}