2.4 / main

#include <iostream>
#include <conio.h>
#include <math.h>

using namespace std;

class vector
 {
  public:	
 	
	double xx;  
 	double yy;  
 
 	vector()  { xx=yy=0; } 
 	vector(double x, double y) 
 	 {
 	 	xx=x; yy=y;
	  }
	
 	
	vector operator+=(const vector &op2)
 	{
		xx=xx+op2.xx;
 		yy=yy+op2.yy;
 		vector s(xx, yy);
 		return s;
	 }


	friend vector operator+(const vector &op1, const vector &op2);
	friend vector operator-(const vector &op1, const vector &op2);
	        friend istream &operator>>(istream &in, vector &A);
        	friend ostream &operator<<(ostream &out, vector &A);

 };


 	vector operator+(const vector &op1, const vector &op2)
 	{
 		vector s;
 		s.xx=op1.xx + op2.xx;
 		s.yy=op1.yy + op2.yy;
 		return s;
	 }
	 
 	vector operator+(const vector &op1, const int &op2)
 	{
 		vector s;
 		s.xx=op1.xx + op2;
 		s.yy=op1.yy + 0;
 		return s;
	 }

 	
	 vector operator*(const vector &op1, const vector &op2)
 	{
 		vector s;
 		s.xx=op1.xx*op2.xx + op1.yy*op2.yy;
 		s.yy=0;
 		return s;
	 }
	
    istream &operator>>(istream &in, vector &A)
    {
    	cout <<"\nВведите х ->";
        in >> A.xx;
        cout <<"\nВведите у ->";
        in >> A.yy;
        return in;
    }

   
    ostream& operator<<(ostream &out, vector &A)
    {
        out << A.xx << " ; " << A.yy ;
        return out;
    }
    
////////////////////////////////////////////////////////////////    
int main(int argc, char** argv) {
//.............................................
	int choice=0;
	vector v1, v2, v3;
    double a;
	setlocale(0,"");

	while(1)
	{
	cout<<"\n\n1. Enter number\n2. Out number \n3. Sum 2 Vect \n4. Mul 2 vect \n5. Exit";
	choice=getch();
	  switch(choice)
	  {
	  	case '1':
			cout<<"\nEnter-> ";
			cin>>v1;
	  		break;
	  		
	  	case '2':
	  		cout<<"\nC="<<v1;
	  		break;
	  		
	  	case '3':
			{
			cout<<"\nEnter v1-> "; 
				cin>>v1;
			cout<<"\nEnter v2-> "; 
				cin>>v2;
			v3=v1+v2;	
			cout<<"\nv1+v2 = " << v3;   
			break;}
			
			
			case '4':
			{
			cout<<"\nEnter v1-> "; 
				cin>>v1;
			cout<<"\nEnter v2-> "; 
				cin>>v2;
			v3=v1*v2;	
			cout<<"\nv1*v2 = " << v3;   
			break;}
			
	  	default: 
	  	goto mEnd;	
	  	break;
	  } // end swtch
	}// end while
	mEnd:
	return 0;
}