#include <iostream.h> #include <math.h> class vector { public: double x; double y; vector (double = 0, double = 0); vector operator + (vector); vector operator - (vector); vector operator - (); vector operator * (double a); double module(); void set_length (double = 1); }; vector::vector (double a, double b) { x = a; y = b; } vector vector::operator + (vector a) { return vector (x + a.x, y + a.y); } vector vector::operator - (vector a) { return vector (x - a.x, y - a.y); } vector vector::operator - () { return vector (-x, -y); } vector vector::operator * (double a) { return vector (x * a, y * a); } double vector::module() { return sqrt (x * x + y * y); } void vector::set_length (double a) { double length = this->module(); x = x / length * a; y = y / length * a; } ostream& operator << (ostream& o, vector a) { o << "(" << a.x << ", " << a.y << ")"; return o; } void main () { vector a; vector b; vector c (3, 5); a = c * 3; a = b + c; c = b - c + a + (b - a) * 7; c = -c; cout << "The module of vector c : " << c.module() << endl; cout << "The content of vector a : " << a << endl; cout << "The oposite of vector a : " << -a << endl; c.set_length(2); // Transforms c in a vector of size 2. a = vector (56, -3); b = vector (7, c.y); b.set_length(); // Transforms b in an unitary vector. cout << "The content of vector b : " << b << endl; double k; k = vector(1, 1).module(); // k will contain 1.4142. cout << "k contains : " << k << endl; }