// Massingill, Berna L.
// 2000 Apr 04
// CS1321

// Copyright notice added by:
// Oldham, Jeffrey D. 
// 2000 Apr 05

// Simple (?) example of use of Tree class.

// (c) 2000 Berna L. Massingill and Jeffrey D. Oldham
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//

#include <iostream>
#include <cassert>
#include "tree.h"
using namespace std;

typedef Tree<int> iTree;
typedef Tree<char> cTree;

// Function to print contents of tree -- root, then left subtree,
//   then right subtree, indented to show nesting.
// Pre:  indents is the number of tabs to print at the start of each
//         line (in addition to the ones used to show nesting).
// Post:  tree "t" printed to output stream "out".
template <typename ItemType>
void printTree(ostream & out, const Tree<ItemType> &t, 
	       const int indents = 0);

// Main program.
int main(void)
{
  iTree it0;			// empty tree of integers.
  assert (!it0);

  iTree it1(1);			// tree with a single node (1).
  assert (it1.left().empty());	// its left subtree is empty.
  assert (it1.right().empty());	// its right subtree is empty.
  assert (it1.item() == 1);	// its root item is 1.

  cout << "A simple tree of ints:\n";
  printTree(cout, it1);
  cout << endl;

  iTree itNonTriv(0,
		  iTree(1, iTree(2), iTree(3)),
		  iTree(4, 
			iTree(5, iTree(6), it0),
			iTree(7, it0, iTree(8))
			)
		  );		// moderately complicated tree.

  cout << "A moderately complicated tree of ints:\n";
  printTree(cout, itNonTriv);
  cout << endl;

  cout << "Its root item again:\n";
  cout << itNonTriv.item() << endl;
  cout << "Its left subtree again:\n";
  printTree(cout, itNonTriv.left());
  cout << "Its right subtree again:\n";
  printTree(cout, itNonTriv.right());
  cout << endl;

  cTree ct0;			// empty tree of characters.
  assert (ct0.empty());

  cTree ct1('a');		// tree with a single node ('a').
  assert (ct1.left().empty());	// its left subtree is empty.
  assert (ct1.right().empty());	// its right subtree is empty.
  assert (ct1.item() == 'a');	// its root item content is 'a'.

  cout << "A simple tree of chars:\n";
  printTree(cout, ct1);
  cout << endl;

  cTree ctNonTriv('a',
		  cTree('b', cTree('c'), cTree('d')),
		  cTree('e', 
			cTree('f', cTree('g'), ct0),
			cTree('h', ct0, cTree('i'))
			)
		  );		// moderately complicated tree.

  cout << "A moderately complicated tree of chars:\n";
  printTree(cout, ctNonTriv);
  cout << endl;

  cout << "Its root item again:\n";
  cout << ctNonTriv.item() << endl;
  cout << "Its left subtree again:\n";
  printTree(cout, ctNonTriv.left());
  cout << "Its right subtree again:\n";
  printTree(cout, ctNonTriv.right());
  cout << endl;

  cout << "\nThat's all, folks!\n";
  return 0;
}

// Function definitions.

// Helper function.
void printTabs(ostream & out, const int n)
{
  for (int i = 0; i < n; i++)
    out << '\t';
  return;
}

// Function to print tree.
template <typename ItemType>
void printTree(ostream & out, const Tree<ItemType> &t, 
	       const int indents)
{
  if (t.empty()) {
    printTabs(out, indents);
    out << "empty tree\n";
  }
  else {
    printTabs(out, indents);
    out << "root = " << t.item() << endl;
    printTabs(out, indents);
    out << "left subtree = \n";
    printTree(out, t.left(), indents+1);
    printTabs(out, indents);
    out << "right subtree = \n";
    printTree(out, t.right(), indents+1);
  }
  return;
}