// CS11 Laboratory #4: First Looks
// Description:  This program provides some demonstrations of the
//      IF statement.

// Program expects as input three numbers in non-decreasing order. It then
// determines whether the numbers correspond to lengths of sides of a triangle
#include <iostream.h>

int main()
{
  int Side1, Side2, Side3;

  // prompt use to type 3 numbers in non-decreasing order

  cout << "\n\n"
		 << "Please type in lengths of sides of your possible triangle.\n"
		 << "We require that the numbers be in non-decreasing order.\n"
		 << "That is, first number <= second number <= third number.\n\n";

  cout << "First number: ";
  cin  >> Side1;

  cout << "Second number: ";
  cin  >> Side2;

  cout << "Third number: ";
  cin  >> Side3;

  cout << "\n";

  ////////////////////////////////////
  // make sure user followed our rules
  ////////////////////////////////////

  if ( (Side1 > Side2) || (Side2 > Side3) )
  {
	 cout << "Bad numbers. Program quits.\n";
	 return 0;
  }

  //////////////////////////////////////////////////////////////////////
  // Check to see whether numbers do form sides of a triangle or not. //
  // There are 4 possibilities:                                       //
  // 1.  The numbers cannot form a triangle                           //
  // 2.  Equilateral triangle  (all sides equal)                      //
  // 3.  Isosceles triangle    (two sides equal)                      //
  // 4.  Scalene triangle       (no sides equal)                      //
  //////////////////////////////////////////////////////////////////////
  if (Side1 + Side2 <= Side3)
  {
	 cout << "Numbers are not the sides of a triangle.\n";
  }
  else if (Side1 == Side3)
  {
	 cout << "Numbers are the sides of an equilateral triangle.\n";
  }
  else if ( (Side1 == Side2) || (Side2 == Side3) )
  {
	 cout << "Numbers are the sides of an isosceles triangle.\n";
  }
  else
  {
	 cout  << "Numbers are the sides of a scalene triangle.\n";
  }

  return 0;
}