#include <iostream>
using namespace std;
class mystring
{
public:
mystring();
~mystring(){}
mystring(const char *str);
mystring(mystring &str);
mystring& operator =(const mystring& str);
mystring& operator =(const char *c_str);
char operator [](const unsigned int index);
mystring strcat (const mystring& str);
mystring strcat (const char *c_str);
mystring substring(int i,int j);//截取子链
mystring substring(int i);
bool operator >(const mystring& str);
bool operator >(const char *c_str);
bool operator >=(const mystring& str);
bool operator >=(const char *c_str);
bool operator <(const mystring& str);
bool operator <(const char *c_str);
bool operator <=(const mystring& str);
bool operator <=(const char *c_str);
mystring strcopy(mystring src);
mystring strcopy(char *str);
char *getstring();
int length();
void clear();
private:
char *m_string;
unsigned int m_size;
public:
friend ostream& operator <<(ostream& ostr,mystring& str)
{
ostr<<str.getstring();
return ostr;
}
friend istream& operator >>(istream& istr,mystring& str)
{
char temp[255];
istr>>temp;
str=temp;
return istr;
}
};
mystring::mystring()
{
m_string=NULL;
m_size=0;
}
mystring::mystring(const char *str)
{
int i=0;
char *strings;
m_size=0;
while (str[m_size]!='\0')
{
m_size++;
}
m_string=new char[m_size+1];
strings=m_string;
while(str[i]!='\0')
{
*strings=str[i];
strings++;
i++;
}
*strings='\0';
}
mystring::mystring(mystring &str)
{
char *strings,*strings1;
strings1=str.m_string;
m_size=str.m_size;
strings=new char[m_size];
m_string=strings;
while(*strings1!='\0')
{
*strings=*strings1;
strings1++;
strings++;
}
*strings='\0';
}
char *mystring::getstring()
{
return m_string;
}
int mystring::length()
{
return m_size;
}
void mystring::clear()
{
if( !m_string )
{
delete []m_string;
m_string = NULL;
}
m_size = 0;
}
mystring& mystring::operator =(const mystring& str)
{
int i=0;
char *strings;
clear();
m_size=str.m_size;
strings=new char[m_size];
m_string=strings;
while(str.m_string[i]!='\0')
{
*strings=str.m_string[i++];
strings++;
}
*strings='\0';
return *this;
}
mystring& mystring::operator =(const char *c_str)
{
int i=0;
char *mm_string;
cout<<c_str;
while (c_str[i]!='\0')
i++;
clear();
m_string=new char[i];
mm_string=m_string;
while (c_str[i]!='\0')
{
*mm_string=c_str[i];
i++;
mm_string++;
}
*mm_string='\0';
return *this;
}
char mystring::operator [](const unsigned int index)
{
return(m_string[index]);
}
mystring mystring::strcat (const mystring& str)
{
int i,j=0;
char *strings1,*strings2;
i=str.m_size+m_size;
strings1=new char[i+1];
strings2=strings1;
while (m_string[j]!='\0')
{
*strings1=m_string[j];
strings1++;
j++;
}
j=0;
while(str.m_string[j]!='\0')
{
*strings1=str.m_string[j];
strings1++;
j++;
}
*strings1='\0';
return mystring(strings2);
}
mystring mystring::strcat (const char *c_str)
{
int i=0,j=0;
char *strings1,*strings2;
while(c_str[i++]!='\0');
i+=m_size;
strings1=new char[i+1];
strings2=strings1;
while (m_string[j]!='\0')
{
*strings1=m_string[j];
strings1++;
j++;
}
j=0;
while(c_str[j]!='\0')
{
*strings1=c_str[j];
strings1++;
j++;
}
*strings1='\0';
return mystring(strings2);
}
mystring mystring::substring(int i,int j)
{
char *strings=new char[j];
int k=0;
while (k<=j-1)
strings[k++]=m_string[i];
strings[k]='\0';
return mystring(strings);
}
mystring mystring::substring(int i)
{
return substring(i,m_size-i+1);
}
bool mystring::operator >(const char *c_str)
{
unsigned int i=0;
bool flag;
while(m_string[i]!='\0'&&c_str[i]!='\0')
{
if (m_string[i]==c_str[i])
{
i++;
continue;
}
else if (m_string[i]>c_str[i])
{
flag=true;
break;
}
else
{
flag=false;
break;
}
}
if (i>=m_size) flag=false;
else flag=m_string[i]>c_str[i];
return flag;
}
bool mystring::operator >(const mystring& str)
{
mystring a(m_string);
return (a>str.m_string);
}
bool mystring::operator >=(const char *c_str)
{
unsigned int i=0;
bool flag;
while(m_string[i]!='\0'&&c_str[i]!='\0')
{
if (m_string[i]==c_str[i])
{
i++;
continue;
}
else if (m_string[i]>c_str[i])
{
flag=true;
break;
}
else
{
flag=false;
break;
}
}
if (m_string[i]=='\0'&&c_str[i]=='\0') flag=true;
else flag=m_string[i]>c_str[i];
return flag;
}
bool mystring::operator >=(const mystring& str)
{
mystring a(m_string);
return (a>=str.m_string);
}
bool mystring::operator <(const char *c_str)
{
mystring a(m_string);
return !(a>=c_str);
}
bool mystring::operator <(const mystring& str)
{
mystring a(m_string);
return !(a>=str.m_string);
}
bool mystring::operator <=(const mystring& str)
{
mystring a(m_string);
return !(a>str.m_string);
}
bool mystring::operator <=(const char *c_str)
{
mystring a(m_string);
return !(a>c_str);
}
mystring mystring::strcopy(char *str)
{
clear();
int i=0;
while (str[i]!='\0')
{
m_string[i]=str[i];
i++;
}
m_string[i]='\0';
m_size=i;
return *this;
}
mystring mystring::strcopy(mystring src)
{
clear();
int i=0;
while (src.m_string[i]!='\0')
{
m_string[i]=src.m_string[i];
i++;
}
m_string[i]='\0';
m_size=i;
return *this;
}
int main()
{
char asds[]="mmmm",bsd[]="mmmmmmmmm";
mystring a(asds);
mystring b(bsd);
a.strcopy(b);
cout<<a;
return 0;
}
