# include <iostream.h>
# include <stdlib.h>
# include "string.h"

void  strcopy(string& dest,string& src)
{
 int i=0;
 while(src.st[i]!='\0')
 {
   dest.st[i]=src.st[i];
   i++;
 }
 dest.st[i]=src.st[i];
 dest.len=src.len;
}


string::string(char *str)
{
 if(strlen(str)<1000)
 {
   len=strlen(str);
   st=new char[len+1];
   strcpy(st,str);
 }
 else
   cout<<"There is not  enough memory\n";
}

void  string:: change(char *str)
{

 if(strlen(str)<1000)
  {
   delete [len+1]st;
   len=strlen(str);
   st=new char[len+1];
   strcpy(st,str);
  }
 else
   cout<<"There is not  enough memory\n";
}



void string::show()
{
  cout<<st<<"\n";
}

char* string::strcats(char* p)
{
  char tmp[1000];
  strcpy(tmp,st);
  delete []st;
  st=new char[strlen(p)+strlen(tmp)+1];
  strcpy(st,tmp);
  strcat(st,p);
  return st;
}


char& string::operator[](int i)
{
  if( i>=0 && i<len )
    return st[i];
  else
  {
    cerr<<"Overflow in string\n";
    exit(1);
  }

}

istream& operator>>(istream& in, string& s)
{
 char buffer[302];
 in.getline(buffer,300);
 s.change(buffer);
 return in;
}

string&  string:: operator=(const string& rhs)
{
 if(this==&rhs) return *this;

 this->len=rhs.len;
 this->change(rhs.st);
 return *this;
}

string string::operator+(const string& rhs)
{
 string tmp;
 tmp.len=this->len +rhs.len+1;
 tmp.change(this->getst());
 tmp+=rhs;
 return tmp;
}

string& string::operator+=(const string& rhs)
{
    this->strcats(rhs.getst());
}