matrix.cpp

VC矩阵类的编写

#include<iostream.h>
class matrix
{
	short rows,cols;
	double * elems;
public:
	matrix(short rows,short cols);
	~matrix();
	double operator () (short row,short col);
	void setelem(short row,short col,double val);
	friend matrix operator + (matrix p,matrix q);
	friend matrix operator - (matrix p,matrix q);
	friend matrix operator * (matrix p,matrix q);
	void print();
};

matrix::matrix(short rows,short cols)
{
	matrix::rows=rows;
	matrix::cols=cols;
    elems=new double[rows * cols];
}
inline matrix::~matrix()
{
//	delete []elems;
}
double matrix::operator () (short row,short col)
{
	return (row>=1 && row<=rows && col>=1 && col<=cols) ? elems[(row-1)*cols+(col-1)] : 0.0;
}
void matrix::setelem(short row,short col,double val)
{
	if(row>=1 && row<=rows && col>=1 && col<=cols)
		elems[(row-1)*cols+(col-1)]=val;
}
matrix operator + (matrix p,matrix q)
{
	matrix m(p.rows,p.cols);
	if(p.rows!=q.rows || p.cols!=q.cols)
		return m;
	for(int r=1;r<=p.rows;r++)
		for(int c=1;c<=p.cols;c++)
			m.setelem(r,c,p(r,c)+q(r,c));
		return m;
}
matrix operator - (matrix p,matrix q)
{
	matrix m(p.rows,p.cols);
	if(p.rows!=q.rows || p.cols!=q.cols)
		return m;
	for(int r=1;r<=p.rows;r++)
		for(int c=1;c<=p.cols;c++)
			m.setelem(r,c,p(r,c)-q(r,c));
		return m;
}
matrix operator * (matrix p,matrix q)
{
	matrix m(p.rows,q.cols);
    if(p.cols!=q.rows)
		return m;
	for(int r=1;r<=p.rows;r++)
		for(int c=1;c<=q.cols;c++)
		{
			m.setelem(r,c,0.0);
			for(int i=1;i<=p.cols;i++)
				m.setelem(r,c,m(r,c)+p(r,i)*q(i,c));
		}
	return m;
}
void matrix::print()
{
	for(int r=1;r<=this->rows;++r)
	{
		for(int c=1;c<=this->cols;c++)
		cout<<(*this)(r,c)<<" ";
		cout<<endl;
	}
}
main()
{
	matrix a(2,3),b(2,3),c(3,2),d(2,3),e(2,2);
	a.setelem(1,1,1.0);
    a.setelem(1,2,2.0);
    a.setelem(1,3,3.0);
	a.setelem(2,1,4.0);
	a.setelem(2,2,5.0);
	a.setelem(2,3,6.0);
	b.setelem(1,1,1.0);
	b.setelem(1,2,2.0);
	b.setelem(1,3,3.0);
	b.setelem(2,1,4.0);
	b.setelem(2,2,5.0);
	b.setelem(2,3,6.0);
	c.setelem(1,1,1.0);
	c.setelem(1,2,4.0);
	c.setelem(2,1,2.0);
	c.setelem(2,2,5.0);
	c.setelem(3,1,3.0);
	c.setelem(3,2,6.0);
	a.print();
	b.print();
	c.print();
	d=a + b;
	d.print();
	d=a - b;
	d.print();   
	e=a * c;
	e.print();   
	return 1;
}