//Bai 23

//Lop doi tuong xau ky tu

#include<iostream>

#include<string.h>

using namespace std;

//Khai bao lop xau ky tu

class XString

{

private:

char* s;

long size;

public:

XString():s(new char[256]),size(256)

{ }

XString(char* str);

XString(const XString& s1);

void input();

void show();

XString& operator=(const XString& r);

XString& operator+(const XString& r);

int operator<(const XString& r);

int operator>(const XString& r);

int operator<=(const XString& r);

int operator>=(const XString& r);

int operator==(const XString& r);

int operator!=(const XString& r);

XString getLWord();

~XString()

{

delete [] s;

}

};

//nen dung ham chuan hoa' xau dung de cat bo dau cach o 2 dau cua xau do

//Ve nha lam them ham chong toan tu cin va cout

//==========CHUONG TRINH CHINH=========

int main()

{

int n,i,j;

XString tg;

cout<<"Nhap vao so luong ho ten: ";cin>>n;cin.ignore();

XString* ds=new XString[n];

cout<<"Nhap danh sach ho ten:

";

for(i=0;i<n;i++)

{

cout<<"\tHo ten nguoi thu "<<(i+1)<<": ";

ds[i].input();

}

//Sap xep

for(i=0;i<n-1;i++)

for(j=i+1;j<n;j++)

if(ds[j].getLWord()<ds[i].getLWord())

{

tg=ds[i];ds[i]=ds[j];ds[j]=tg;

}

cout<<"Danh sach ho ten da sap xep la:

";

cout.setf(ios::left);

cout.width(5);cout<<"STT";

cout.width(40);cout<<"Ho va ten"<<endl;

for(i=0;i<n;i++)

{

cout.width(5);cout<<(i+1);

cout.width(40);ds[i].show();

cout<<endl;

}

delete [] ds;

return 0;

}

//=======DINH NGHIA CAC HAM============

XString::XString(char* str)

{

size=strlen(str)+1;

s=new char[size];

strcpy(s,str);

}

XString::XString(const XString& s1)

{

size=strlen(s1.s)+1;

s=new char[size];

strcpy(s,s1.s);

}

void XString::input()

{

cin.get(s,size);cin.ignore();//sizeof()khong duoc dung. Neu dung se la do dai cua con tro xau ky tu ma khong phai la xau ky tu do, ma phai dung size thi moi dung

}

void XString::show()

{

cout<<s;

}

XString& XString::operator=(const XString& r)

{

delete [] s;

size=strlen(r.s)+1;

s=new char[size];

strcpy(s,r.s);

}

XString& XString::operator+(const XString& r)

{

if(strlen(s)+strlen(r.s)>=size)

{

cout<<"Vuot qua do dai cua xau => khong ghep duoc";

return *this;

}

else strcat(s,r.s);

return *this;

}

int XString::operator<(const XString& r)

{

if(strcmp(s,r.s)<0) return 1;

return 0;

}

int XString::operator>(const XString& r)

{

if(strcmp(s,r.s)>0) return 1;

return 0;

}

int XString::operator<=(const XString& r)

{

if(!strcmp(s,r.s)>0) return 1;

return 0;

}

int XString::operator>=(const XString& r)

{

if(!strcmp(s,r.s)<0) return 1;

return 0;

}

int XString::operator==(const XString& r)

{

if(strcmp(s,r.s)==0) return 1;

return 0;

}

int XString::operator!=(const XString& r)

{

if(strcmp(s,r.s)!=0) return 1;

return 0;

}

XString XString::getLWord()//Khi p chua tro vao ki tu dau tien thi con lui

{

char* p=s+strlen(s)-1;

while(*p!=' ' && p!=s) p--;

if(p!=s) p++;//vi phai kiem tra xem p da tro vao ki tu dau tien chua

return XString(p);//day la ham tao mot doi so voi cai tra ve la mot doi tuong

}