///////////////////////////////////////////////////////////////
//  exmp2a.cpp - C string operations                         //
//                                                           //
//  Jim Fawcett, ELE591\791, Su'99                           //
//                                                           //
//  build: cl /GX exmp2a.cpp                                 //
///////////////////////////////////////////////////////////////

#include <iostream>
#include <cstring>
using namespace std;

//----< function reverses chars in string >--------------------

char* reverse(char *s) {

  int i, len = strlen(s);
  char *temp = new char[len+1];
  if(!temp)
    throw "\n  memory allocation failure\n\n";
  for(i=0; i<len; i++)
    temp[len-i-1] = s[i];
  temp[len] = '\0';
  return temp;
}

//----< test >-------------------------------------------------

void main() {

  cout << "\n  Demonstrating C Strings "
       << "\n =========================\n\n";

  char *str1 = "this is a C style string";

  cout << "\n  String before reversing: " << str1;
  char *str2 = reverse(str1);
  cout << "\n  String after reversing:  " << str2;

  cout << "\n\n  string comparison:\n";

  if(strcmp(str1,str2) == 0)
    cout << "\n  \"" << str1 << "\"\n\t equals \n\t\t\"" 
         << str2 << "\"\n\n";
  else if(strcmp(str1,str2) > 0)
    cout << "\n  \"" << str1 << "\"\n\t is greater than \n\t\t\"" 
         << str2 << "\"\n\n";
  else
    cout << "\n  \"" << str1 << "\"\n\t is less than \n\t\t\"" 
         << str2 << "\"\n\n";

  delete str2;
}