// file tree.cpp

// methods for class Tree

#include <assert.h>

#include <stdlib.h>

#include <iostream.h>

#include "tree.h"

Tree::Tree()

{

root = NULL;

}

Tree::Tree(Type x)

{

root = new Tnode;

assert(root);

root->setinfo(x);

}

void Tree::makeroot(Type x)

{

root = new Tnode;

assert(root);

root->setinfo(x);

}

Tree::~Tree()

{

if (isempty()) return;

clear(root);

}

void Tree::clear (Tnode *t)

{

if (t==NULL) return;

clear(t->getleft());

clear(t->getright());

delete t;

}

int Tree::isempty()

{

return (root==NULL);

}

Tnode *Tree::getroot()

{

return root;

}

Type Tree::getdata()

{

assert(root);

return root->getinfo();

}

Tnode *Tree::getleft()

{

assert(root);

return root->getleft();

}

Tnode *Tree::getright()

{

assert(root);

return root->getright();

}

void Tree::setdata(Type x)

{

assert(root);

root->setinfo(x);

}

void Tree::insertleft(Tnode *p, Type x)

{

Tnode *q;

assert(p);

assert(!(p->getleft()));

q = new Tnode;

assert(q);

p->setleft(q);

q->setinfo(x);

}

void Tree::insertright(Tnode *p, Type x)

{

Tnode *q;

assert(p);

assert(!(p->getright()));

q = new Tnode;

assert(q);

p->setright(q);

q->setinfo(x);

}

void Tree::print(int mode)

{

assert(mode>=1 && mode<=3);

if (mode==1) pretrav();

if (mode==2) intrav();

if (mode==3) postrav();

}

void Tree::pretrav()

{

if (isempty()) return;

pretrav(root);

cout<<endl<<endl;

}

void Tree::pretrav(Tnode *t)

{

if (t==NULL) return;

cout<<t->getinfo()<<' ';

pretrav(t->getleft());

pretrav(t->getright());

}

void Tree::intrav()

{

if (isempty()) return;

intrav(root);

cout<<endl<<endl;

}

void Tree::intrav(Tnode *t)

{

if (t==NULL) return;

intrav(t->getleft());

cout<<t->getinfo()<<' ';

intrav(t->getright());

}

void Tree::postrav()

{

if (isempty()) return;

postrav(root);

cout<<endl<<endl;

}

void Tree::postrav(Tnode *t)

{

if (t==NULL) return;

postrav(t->getleft());

postrav(t->getright());

cout<<t->getinfo()<<' ';

}