#include <iostream.h>
#include <string.h>
class MyString
{
public:
MyString() {m_data = NULL;}
MyString(const char *str);
~MyString();
MyString operator-(const MyString &other);
MyString operator=(const MyString &other);
friend ostream &operator<<(ostream &stream, const MyString &str);
//重载输出运算符"<<"
private:
char *m_data;
};
#define NULL 0
MyString::~MyString()
{
if(m_data)
delete [] m_data;
m_data = NULL;
}
MyString::MyString(const char *str)
{
if(str == NULL)
{
m_data = new char[1];
*m_data = '\0';
}
else
{
int length = strlen(str);
m_data = new char[length+1];
strcpy(m_data, str);
}
}
MyString MyString::operator=(const MyString &other)
{
if(this==&other)
return *this;
delete m_data;
m_data=new char[strlen(other.m_data)+1];
strcpy(m_data,other.m_data);
return *this;
}
MyString MyString::operator-(const MyString &other)
{ int i,j,t=0,m;