Write a Program to overload operators

Write a Program to overload operators like *, <<, >> using friend function. The following overloaded operators should work for a class vector. 

#include<iostream.h>
#include<conio.h>
const size = 3;
class vector
{
int v[size];
public:
vector();
vector(int *x);
friend vector operator *(int a, vector b);
friend vector operator *(vector b, int a);  
friend istream & operator >>(istream &, vector &);
friend ostream & operator <<(ostream &, vector &);
};
vector ::vector()
{
for(int i=0;i<size;i++)
v[i]=0;
}
vector :: vector(int *x)
{
for(int i=0; i<size; i++)
v[i] = x[i];
}
vector operator *(int a, vector b)
{
vector c;
for(int i=0; i<size; i++)
c.v[i] = a * b.v[i];
return c;
}
vector operator *(vector b, int a)
{
vector c;
for(int i=0; i<size; i++)
c.v[i] = b.v[i] * a;  return c;
}
istream & operator >> (istream &din, vector &b)
{
for(int i=0; i<size; i++)
din>>b.v[i];
return(din);
}


ostream & operator << (ostream &dout, vector &b)
{
dout<<"("<<b.v [0];
for(int i=1; i<size; i++)
dout<<","<<b.v[i];
dout<<")";
return(dout);
}
int x[size] = {2,4,6};
int main()
{   
vector m;
vector n = x;
cout<<"Enter Elements of vector m"<<"\n";
cin>>m;
cout<<"\n";
cout<<"m="<<m<<"\n";
vector p,q;
p = 2 * m;
q = n * 2;
cout<<"\n";
cout<<"p="<<p<<"\n";
cout<<"q="<<q<<"\n"; 
return 0;
}