// Program to overload arithmatic operators for Vectors.
// Assignment-25
// vectoo.cpp, Author - Krishna Kumar Khatri.

// Uncomment ONLY the following line if you are using Turbo/Borland compiler.
//#define TC
#ifdef TC
	#include <iostream.h>
	#include <iomanip.h>
#else
	#include <iostream>
	#include <iomanip>
	using namespace std;
#endif
#include <conio.h>  // For getch.
const int MAXSIZE = 500;
const int null = 0;

class Vector
{
        int vect[MAXSIZE];
        int sz;
    public:
        Vector(const int&);
		Vector operator+(const Vector&);
		Vector operator+(const int&);
		Vector operator++();      // Pre.
		Vector operator++(int);   // Post.
		Vector operator-(const Vector&);
		Vector operator-(const int&);
		Vector operator--();      // Pre.
		Vector operator--(int);   // Post.
		friend ostream& operator<<(ostream&, const Vector&);
};

Vector::Vector(const int& empty)
{
	int i, inpt;

	// If the user is not supposed to fill up the vector (initialize)
	// empty is true (1), false (0) otherwise.
	if (empty == 0) {
		cout << endl << "Enter -1 to terminate the input." << endl;
		cout << "Max no. of elements allowed " << MAXSIZE << ": ";
		for (i = 0; i < MAXSIZE; i++) {
			cin >> inpt;
			if (inpt != -1)
				vect[i] = inpt;
			else
				break;
		}
		sz = i;
	} else
		sz = 0;
}

Vector Vector::operator+(const Vector& sparam)
{
	Vector res(1);  // This vector must initially be empty.
	int i;

	if (this->sz == sparam.sz) {
		res.sz = sparam.sz; // Reinitialize the resultant vector's sz.
		for (i = 0; i < sparam.sz; i++)
			res.vect[i] = this->vect[i] + sparam.vect[i];
	}
	else
		cout << endl << endl << "Vector size mismatch!";
    return res;	
}

Vector Vector::operator+(const int& inc)
{
    Vector res(1);
    int i;
    
    res.sz = this->sz;
	for (i = 0; i < this->sz; i++)
		res.vect[i] = this->vect[i] + inc;

    return res;
}

Vector Vector::operator++()
{ 
    *this = *this + 1; 
    return *this;
}

Vector Vector::operator++(int dummy)
{
    Vector save(1);
    save = *this;
    *this = *this + 1; 
    return save;
}

Vector Vector::operator-(const Vector& sparam)
{
	Vector res(1);  // This vector must initially be empty.
	int i;

	if (this->sz == sparam.sz) {
		res.sz = sparam.sz; // Reinitialize the resultant vector's sz.
		for (i = 0; i < sparam.sz; i++)
			res.vect[i] = this->vect[i] - sparam.vect[i];
	}
	else
		cout << endl << endl << "Vector size mismatch!";
	return res;
}

Vector Vector::operator-(const int& dec)
{
    Vector res(1);
    int i;
    
    res.sz = this->sz;
	for (i = 0; i < this->sz; i++)
		res.vect[i] = this->vect[i] - dec;

    return res;
}

Vector Vector::operator--()
{ 
    *this = *this - 1; 
    return *this;
}

Vector Vector::operator--(int dummy)
{
    Vector save(1);
    save = *this;
    *this = *this - 1; 
    return save;
}

ostream& operator<<(ostream& os, const Vector& v)
{
	int sz = v.sz;
	int i;

	if (v.sz != 0) {
        for (i = 0; i < sz; i++)
		  (i + 1) < sz ? os << setw(3) << v.vect[i] << ", " :
                         os << setw(3) << v.vect[i];
    } else
        os << "NULL Vector.";
    return os;
}

int main()
{
    #ifdef TC
        clrscr();
    #endif
    int i, n;
    char choice;
	Vector res(1);  // This vector must initially be empty.
    
    cout << "Enter data for first vector: ";
    Vector vect1(0);
    cout << endl << "Enter data for second vector: ";
    Vector vect2(0);
    
	res = vect1 + vect2;
	cout << endl << "Vector + > ";
	cout << res;

	res = vect1 - vect2;
	cout << endl << "Vector - > ";
	cout << res;

	++vect1;
	cout << endl << endl << "Vector-1 ++ > ";
	cout << vect1;
	
	--vect2;
	cout << endl << "Vector-2 -- > ";
	cout << vect2;

	cout << endl << endl << "Program over. Press any key to exit...";
	getch();
	return 0; // Successful termination.
}