c++矩阵

这里讲的矩阵有创建矩阵，矩阵加法，矩阵乘法，输出矩阵这些功能。

#include<iostream>

using namespace std;

template<class T>

class matrix       //矩阵节点

{

public:

matrix(int theRows = 0, int theColumns = 0);

matrix(const matrix<T>&);

~matrix() { delete[] element; };

int rows()const { return theRows; };

int cols()const { return theColumns; };

T& operator()(int i, int j)const;

matrix<T>& operator=(const matrix<T>&);

matrix<T> operator+()const;

matrix<T> operator+(const matrix<T>&)const;

matrix<T> operator-()const;

matrix<T> operator-(const matrix<T>&)const;

matrix<T> operator*(const matrix<T>&)const;

matrix<T>& operator+=(const T&);

void Input();

void Output();

private:

int theRows;

int theColumns;

T* element;             //元素

};

template<class T>

matrix<T>::matrix(int theRows, int theColumns)

{

if (theColumns < 0 || theRows < 0)

{

cout<<"Rows and Cols must be >= 0 ";

}

if ((theColumns == 0 || theRows == 0) && (theColumns != 0 || theRows != 0))

{

cout<<"Either both or neither rows and columns should be zero ";

}

this->theColumns = theColumns;

this->theRows = theRows;

element = new T[theColumns * theRows];

}

template<class T>

matrix<T>::matrix(const matrix<T>& m)

{

theColumns = m.theColumns;

theRows = m.theRows;

size_t number = theColumns * theRows;

element = new T[number];

copy(m.element, m.element + number, element);

}

template<class T>

matrix<T>& matrix<T>::operator=(const matrix<T>& m)

{

if (this != &m)

{

delete[] element;

theColumns = m.theColumns;

theRows = m.theRows;

size_t number = theColumns * theRows;

element = new T[number];

copy(m.element, m.element + number, element);

}

return *this;

}

template<class T>

T& matrix<T>::operator()(int i, int j) const

{

if (i<1 || i>theRows || j<1 || j>theColumns)

{

cout<<"Matrix Index Out Of Bounds ";

}

return element[(i - 1)*theColumns + j - 1];

}

//矩阵相加

template<class T>

matrix<T> matrix<T>::operator+(const matrix<T>& m)const

{

if (theRows != m.theRows || theColumns != m.theColumns)

{

cout<< "Matrix Size is Out of batch ";

}

matrix<T> w(theRows, theColumns);

size_t number = theColumns*theRows;

for (int i = 0; i < number; i++)

{

w.element[i] = element[i] + m.element[i];

}

return w;

}

//矩阵相乘

template<class T>

matrix<T> matrix<T>::operator*(const matrix<T>& m)const

{

if (theColumns != m.theRows || theRows != m.theColumns)

{

cout<<"Matrix Style is Out of batch ";

}

matrix<T> w(theRows, theColumns);

int ct = 0;

int cm = 0;

int cw = 0;

for (int i = 1; i <= theRows; i++)

{

for (int j = 1; j <= theColumns; j++)

{

T sum = element[ct] * m.element[cm];

for (int k = 2; k <= theColumns; k++)

{

ct++;

cm += m.theColumns;

sum += element[ct] * m.element[cm];

}

w.element[cw++] = sum;

ct -= theColumns - 1;

cm = j;

}

ct += theColumns;

cm = 0;

}

return w;

}

//输入矩阵

template<class T>

void matrix<T>::Input()

{

size_t number = theColumns * theRows;

for (int i = 0; i < number; i++)

{

cin >> element[i];

}

cout << "Input fanished" << endl;

return;

}

//输出矩阵

template<class T>

void matrix<T>::Output()

{

size_t number = theColumns * theRows;

for (int i = 0; i < theRows; i++)

{

for (int j = 0; j < theColumns; j++)

{

cout << element[i*theColumns + j] << " ";

}

cout << endl;

}

cout << "Output finished " << endl;

return;

}

int main()

{

matrix<int> a(3, 3);

matrix<int> b(3, 3);

matrix<int> c(3, 3);

matrix<int> d(3, 3);

a.Input();

b.Input();

c= a * b;

d=a+b;

c.Output();

d.Output();

return 0;

}