C++ Programming Hoimework 4 Solution

● (80 points) Re-write the String class from homework 3, but use a singly-linked list as the representation. Like last week, these strings will be of varying lengths and must grow and shrink as necessary. Implement all the appropriate methods given below.
● Class String declaration:
class String
{
public:
/// Both constructors should construct
/// from the parameter s
String( const char * s = "");
String( const String & s );
String operator = ( const String & s );
char & operator [] ( const int index );
int length() const;
int indexOf( char c ) const;
bool operator == ( const String & s ) const;
/// concatenates this and s
String operator + ( const String & s ) const;
/// concatenates s onto end of this
String operator += ( const String & s );
void print( ostream & out );
void read( istream & in );
~String();
private:
bool inBounds( int i )
{
return i = 0 && i < length();
}
struct ListNode
{
char info;
ListNode * next;
ListNode(char newInfo, ListNode * newNext)
: info( newInfo ), next( newNext )
{
}
};
ListNode * head; // no other data members!!
};
ostream & operator << ( ostream & out, String str );
istream & operator ( istream & in, String & str );
● (10 points) Write a main function which tests each function defined in your class
String. You may use the same one from last week if you like, but notice I deleted
some of the methods.
● (10 points) Give an estimate of the relative efficiency of each of the following two
assignments (I mean how many function calls, how many copies are made, etc):
String s("Hello");
String t("There");
s = s + t;
s += t;