第七次作业反馈及参考答案

第七次的模板类编写要求挺高的，鉴于大家的作业完成得不理想，决定本次作业不纳入最后的作业考核中，只供大家练习（大家没意见吧？）。

对于模板类的几点解释：

一：模板类比较特殊，目前绝大多数编译器不支持模板的分离编译模式，所以有3个方案，

（1）将模板类的声明和定义放到一个头文件（.H文件）中；

（2）或者声明和定义还是分开来写，可以在.h文件的最后将.cpp文件包含进来（参考代码选用这种方式）；

（3）将类和主函数写在一个CPP文件里。（个人比较推荐这种方式应付考试）

（之前几位同学问我的时候我没有去试过，说的不对，误导了，先道个歉，以这次反馈为准）

PS：不多说了，大家直接看参考答案吧。。

Matrix.h

#ifndef MATRIX_H#define MATRIX_H#include <iostream>using namespace std;template <typename elemType, int row = 4, int col = 4>class Matrix{friend class Matrix;template <typename elemType, int row, int col>friend ostream& operator << (ostream&, const Matrix<elemType, row, col>&);public:Matrix();Matrix(const Matrix&);~Matrix();void ReadData();elemType Max() const;elemType Min() const;template <int irow, int icol>bool operator == (const Matrix<elemType, irow, icol>&) const;Matrix operator + (const Matrix&) const;template<int icol>Matrix<elemType, row, icol> operator * (const Matrix<elemType, col, icol>&) const;private:int _row, _col;elemType **_matrix;};#include "Matrix.cpp"#endif

Matrix.cpp

#ifndef MATRIX_CPP#define MATRIX_CPP#include "Matrix.h"#include <iostream>#include <cstdlib>using namespace std;template <typename elemType, int row, int col>Matrix<elemType, row, col>::Matrix(): _row(row), _col(col){_matrix = new elemType*[_row];for (int i = 0; i < _row; i ++){_matrix[i] = new elemType[_col];for (int j = 0; j < _col; j ++)_matrix[i][j] = elemType();}}template <typename elemType, int row, int col>Matrix<elemType, row, col>::Matrix(const Matrix& rhs): _row(rhs._row), _col(rhs._col){_matrix = new elemType*[_row];for (int i = 0; i < _row; i ++){_matrix[i] = new elemType[_col];for (int j = 0; j < _col; j ++)_matrix[i][j] = rhs._matrix[i][j];}}template <typename elemType, int row, int col>Matrix<elemType, row, col>::~Matrix(){for (int i = 0; i < _row; i ++)delete[] _matrix[i];delete[] _matrix;}template <typename elemType, int row, int col>void Matrix<elemType, row, col>::ReadData(){cout << "Please Input An Matrix Of " << _row << " * " << _col << endl;for (int i = 0; i < _row; i ++)for (int j = 0; j < _col; j ++)cin >> _matrix[i][j];}template <typename elemType, int row, int col>elemType Matrix<elemType, row, col>::Max() const{elemType max(_matrix[0][0]);for (int i = 0; i < _row; i ++)for (int j = 0; j < _col; j ++)if (_matrix[i][j] > max)max = _matrix[i][j];return max;}template <typename elemType, int row, int col>elemType Matrix<elemType, row, col>::Min() const{elemType min(_matrix[0][0]);for (int i = 0; i < _row; i ++)for (int j = 0; j < _col; j ++)if (min > _matrix[i][j])min = _matrix[i][j];return min;}template <typename elemType, int row, int col>template <int irow, int icol>bool Matrix<elemType, row, col>::operator == (const Matrix<elemType, irow, icol>& rhs) const{if (_row != irow || _col != icol)return false;for (int i = 0; i < _row; i ++)for (int j = 0; j < _col; j ++)if (_matrix[i][j] != rhs._matrix[i][j])return false;return true;}template <typename elemType, int row, int col>Matrix<elemType, row, col> Matrix<elemType, row, col>::operator + (const Matrix& rhs) const{Matrix<elemType, row, col> tmp;for (int i = 0; i < _row; i ++)for (int j = 0; j < _col; j ++)tmp._matrix[i][j] = _matrix[i][j] + rhs._matrix[i][j];return tmp;}template <typename elemType, int row, int col>template <int icol>Matrix<elemType, row, icol> Matrix<elemType, row, col>::operator * (const Matrix<elemType, col, icol>& rhs) const{Matrix<elemType, row, icol> tmp;for (int i = 0; i < _row; i ++)for (int j = 0; j < rhs._col; j ++){bool plus = false;for (int k = 0; k < _col; k ++)if (!plus){tmp._matrix[i][j] = _matrix[i][k] * rhs._matrix[k][j];plus = true;}elsetmp._matrix[i][j] = tmp._matrix[i][j] + _matrix[i][k] * rhs._matrix[k][j];}return tmp;}template <typename elemType, int row, int col>inline ostream& operator << (ostream& os, const Matrix<elemType, row, col>& rhs){for (int i = 0; i < rhs._row; i ++){for (int j = 0; j < rhs._col; j ++)os << rhs._matrix[i][j] << " ";os << endl;}return os;}#endif

main.cpp

#include "Matrix.h"#include <iostream>using namespace std;int main(){Matrix<int, 2, 3> matrix_1;matrix_1.ReadData();Matrix<int, 2, 3> matrix_2(matrix_1);Matrix<int, 3, 2> matrix_3;matrix_3.ReadData();cout << "matrix_1:\n" << matrix_1;cout << "matrix_1's maximum number: " << matrix_1.Max() << endl<< "matrix_1's minimum number: " << matrix_1.Min() << endl;cout << "matrix_1 " << (matrix_1 == matrix_2 ? "" : "not") << "equal to matrix_2" << endl;cout << "matrix_1:\n" << matrix_1;cout << "matrix_2:\n" << matrix_2;cout << "matrix_1 plus matrix_2" << endl;cout << matrix_1 + matrix_2 << endl;cout << "matrix_1 " << (matrix_1 == matrix_3 ? "" : "not") << "equal to matrix_3" << endl;cout << "matrix_1:\n" << matrix_1;cout << "matrix_3:\n" << matrix_3;cout << "matrix_1 multi matrix_3" << endl<< matrix_1 * matrix_3;return 0;}