Program for demonstration of Tree Operations - INSERTION, INORDER .

# include
# include
# include

struct node
{
struct node *left;
int data;
struct node *right;
};

void main()
{
void insert(struct node **,int);
void inorder(struct node *);
void postorder(struct node *);
void preorder(struct node *);
struct node *ptr;
int will,i,num;
ptr = NULL;
ptr->data=NULL;
clrscr();

printf("Enter the number of terms you want to add to the tree.");
scanf("%d",&will);

/* Getting Input */
for(i=0;i {
printf("Enter the item");
scanf("%d",&num);
insert(&ptr,num);
}

getch();
printf("INORDER TRAVERSAL");
inorder(ptr);
getch();
printf("PREORDER TRAVERSAL");
preorder(ptr);
getch();
printf("POSTORDER TRAVERSAL");
postorder(ptr);
getch();
}



void insert(struct node **p,int num)
{


if((*p)==NULL)
{ printf("Leaf node created.");
(*p)=malloc(sizeof(struct node));
(*p)->left = NULL;
(*p)->right = NULL;
(*p)->data = num;
return;
}
else
{ if(num==(*p)->data)
{
printf("REPEATED ENTRY ERROR
VALUE REJECTED");
return;
}
if(num<(*p)->data)
{
printf("
Directed to left link.");
insert(&((*p)->left),num);
}
else
{
printf("Directed to right link.");
insert(&((*p)->right),num);
}
}
return;
}


void inorder(struct node *p)
{
if(p!=NULL)
{
inorder(p->left);
printf("Data :%d",p->data);
inorder(p->right);
}
else
return;
}


void preorder(struct node *p)
{
if(p!=NULL)
{
printf("Data :%d",p->data);
preorder(p->left);
preorder(p->right);
}
else
return;
}


void postorder(struct node *p)
{
if(p!=NULL)
{
postorder(p->left);
postorder(p->right);
printf("
Data :%d",p->data);
}
else
return;
}