#include <stdio.h>
#include <string.h>

class String {
	char *str;
	int   size;
	int   len;

	// construtor privado
	String( int s ) { len = 0; size = s; str = new char[size]; }

 public:
	String( char * s = "" );
	~String() { delete str; }

	int lenght() { return len; }

	// comparacoes
	int operator==(String& s) { return strcmp(str, s.str) == 0; }
	int operator< (String& s) { return strcmp(str, s.str) <  0; }
	int operator<=(String& s) { return strcmp(str, s.str) <= 0; }
	int operator> (String& s) { return strcmp(str, s.str) >  0; }
	int operator>=(String& s) { return strcmp(str, s.str) >= 0; }

	// atribuicao
	String& operator=(String& s);

	// acesso aos caracteres:
	char& operator[](int i);

	// concatenação
	String operator+(String& s);

	// conversao para char*
	operator const char*() { return str; }
 };

String::String( char * s )
{
  len = strlen(s);
  size = len+1;
  str = new char[size];
  strcpy(str, s);
}

String& String::operator=(String& s)
{
	if (s.len > size+1)
	{
	  // realoca area de memoria
	  delete str;
	  size = s.len+1;
	  str = new char[size];
	}
	len = s.len;
	strcpy(str,s.str);
	return *this;
}

String String::operator+(String& s)
{
	String result(len + s.len + 1);
	strcpy(result.str,str);
	strcat(result.str,s.str);
	return result;
}

char& String::operator[](int i)
{
	if (i<0 || i>=len)
	{
		static char lixo;
		return lixo;
	}
	else return str[i];
}

int main()
{
	String s1, s2, s3;
	String s4("quarta string");
	String s5 = "string s5";

	printf("%s\n", (const char*)s5);
	// ((const char*)s5)[0] = 'X';
	printf("%s\n", (const char*)s5);

	s1 = "primeira";
	s2 = s1 + " " + s4;
	printf("%s\n", (const char*)s2);

	return 0;
}