#include<conio.h>
#include<iostream.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<iomanip.h>


class alphabet {private: int n;char c[100];
	 public:alphabet();
		alphabet(int,int);
		alphabet(char*);
	friend istream& operator>>(istream& in,alphabet& p);
	friend ostream& operator<<(ostream& on,alphabet& p);
	alphabet& operator+(alphabet&);
	alphabet& operator+=(char);
	char* cipher(char*,int);
	char* decipher(char*,int);
	int check (char);
	int checkall(char*);
	int over();
	};

 alphabet::alphabet(){n=0;c[0]=NULL;}

 alphabet::alphabet(int c0,int k){int i;
	n=k;
	for(i=0;i<n;i++)c[i]=c0+i;c[n]=0;}

 alphabet::alphabet(char* s){int i;n=strlen(s);
	strcpy(c,s);}

 int alphabet::over(){int i,j;for(i=0;i<n-1;i++)
	for(j=i+1;j<n;j++)
	if(c[i]==c[j])
	return 0;
	return 1;}

 istream& operator>>(istream& in,alphabet& s){int i;
       cout<<"Enter String=";in.getline(s.c,80);
       s.n=strlen(s.c);
       return in;}

ostream& operator<<(ostream& on,alphabet& s){int i;
	on<<"You See Current Alphabet of "<<s.n<<" characters : "<<endl;
	on<<s.c;return on;}

alphabet& alphabet:: operator+(alphabet& b){
strcat(c,b.c);n=n+b.n;
	return *this;}

alphabet& alphabet::operator+=(char s){
	if(check(s)){cout<<"Symbol Alredy Exists,";return *this;}
	c[n]=s;c[n+1]=0;n++;
	return *this;}


int alphabet::check(char t){int i; for(i=0;i<n;i++)
	if(t==c[i])return 1;return 0;}

int alphabet::checkall(char*t){int i,j;
	for(j=0;j<strlen(t);j++){
	for(i=0;i<n;i++)
	if(!check(t[j]))return 0;}
	return 1;}

char* alphabet::cipher(char*s,int t){int i;
	for(i=0;i<strlen(s);i++)
	s[i]=s[i]+t;
	return s;};

char* alphabet::decipher(char*s,int t){
	int i;for(i=0;i<strlen(s);i++)
	s[i]=s[i]-t;return s;};

void main(){alphabet my;int key,c0,k;char tst[100];char t;
	textmode(C80);
	do{ textattr(0x1F);
	clrscr();
	cprintf("1-Make1,2-Make2,3-Make3,4-Enter,5-Show,6-Sum,Esc-Quit\n\r");
	cprintf("7-Add,8-Cipher,9-Decipher\n\r");
	switch(getch()){
case'1':cout<<my;break;
case'2':cout<<"C0=";cin>>c0;cout<<"K=";cin>>k;
	alphabet my(c0,k);cout<<my;break;
case'3':cout<<"Enter String=";cin>>tst;cin.ignore();
	alphabet b(tst);cout<<b;
	if(!(b.over()))
	cout<<"\nAlphabet Not Correct!";break;
case'4':cin>>my;
	cout<<my;
	if(!(my.over()))
	cout<<"\nAlphabet Not Correct!";break;
case'5':cout<<my;break;
case'6':cout<<"Enter Alphabet N2,";cin>>b;cout<<(my=my+b);
	if(!(my.over()))
	cout<<"\nAlphabet Not Correct!";break;
case'7':cout<<"Enter Character=";cin>>t;cout<<(my+=t);
	break;
case'8':cout<<"Enter String=";cin>>tst;cout<<"Enter Key=";cin>>key;
	if (my.checkall(tst))cout<<my.cipher(tst,key);
	else {cout<<"String Incorrect!";break;}
	if (!(my.checkall(tst)) )
	cout<<"\nString Is Not In Alphabet";
	break;
case'9':cout<<"Enter Key=";cin>>key;cout<<my.decipher(tst,key);break;
case 27:exit(0);
 }
getch();}
while(1);
}