|
#2
rjsp2017-09-15 13:14
在写 class CMatrix 之前，先将 main 代码写好。
这一点非常重要，是先有需求后代码，而不是照着烂代码制定需求。 main大概是这个样子，不同的人可能写出不一样的代码，但大体差不多（绝不会想你写的那样）： （绝不会想你写的那样） int main( void ) { CMatrix a = { 2, 3, { 1, 2, 3 , 4, 5, 6 } }; CMatrix b = { 3, 2, { 1, 4 , 2, 5 , 3, 6 } }; CMatrix c = a * b; cout << "a matrix:\n" << a << '\n'; cout << "b matrix:\n" << b << '\n'; cout << "a*b matrix:\n" << c << '\n'; cout << "Transpose matrix:\n" << c.Transpose() << '\n'; return 0; } 有了用法的代码，class CMatrix 的大体结构就有了，顶多以后会补充一些其它的成员 class CMatrix { public: CMatrix( size_t rownum, size_t colnum, std::initializer_list<int> data={} ); CMatrix( const CMatrix& mtx ); CMatrix( CMatrix&& mtx ) noexcept; CMatrix& operator=( const CMatrix& mtx ); CMatrix& operator=( CMatrix&& mtx ) noexcept; ~CMatrix(); int at( size_t row, size_t col ) const; int& at( size_t row, size_t col ); CMatrix operator*( const CMatrix& mtx ); CMatrix& Transpose(); protected: size_t rownum_, colnum_; int* pdata_; friend std::ostream& operator<<( std::ostream& os, const CMatrix& mtx ); }; 最后，就剩下枯燥的填代码了，没什么好说了的，结束。 随便填了一些，仅供参考：  程序代码：#include <iostream> class CMatrix { public: CMatrix( size_t rownum, size_t colnum, std::initializer_list<int> data={} ); CMatrix( const CMatrix& mtx ); CMatrix( CMatrix&& mtx ) noexcept; CMatrix& operator=( const CMatrix& mtx ); CMatrix& operator=( CMatrix&& mtx ) noexcept; ~CMatrix(); int at( size_t row, size_t col ) const; int& at( size_t row, size_t col ); CMatrix operator*( const CMatrix& mtx ); CMatrix& Transpose(); protected: size_t rownum_, colnum_; int* pdata_; friend std::ostream& operator<<( std::ostream& os, const CMatrix& mtx ); }; #include <new> #include <exception> using namespace std; CMatrix::CMatrix( size_t rownum, size_t colnum, std::initializer_list<int> data ) try : rownum_(rownum), colnum_(colnum), pdata_(new int[rownum_*colnum_]()) { if( rownum_==0 || colnum_==0 ) throw std::invalid_argument( "fuck" ); size_t i = 0; for( const auto& val : data ) { if( i == rownum_*colnum_ ) break; pdata_[i++] = val; } } catch( const std::bad_alloc& ) { throw; } CMatrix::CMatrix( const CMatrix& mtx ) try : rownum_(mtx.rownum_), colnum_(mtx.colnum_), pdata_(new int[rownum_*colnum_]) { std::copy( mtx.pdata_, mtx.pdata_+rownum_*colnum_, pdata_ ); } catch( const std::bad_alloc& ) { throw; } CMatrix::CMatrix( CMatrix&& mtx ) noexcept : rownum_(mtx.rownum_), colnum_(mtx.colnum_), pdata_(mtx.pdata_) { mtx.rownum_ = 0; mtx.colnum_ = 0; mtx.pdata_ = nullptr; } CMatrix& CMatrix::operator=( const CMatrix& mtx ) { if( this != &mtx ) { if( rownum_*colnum_ != mtx.rownum_*mtx.colnum_ ) { delete[] pdata_; pdata_ = nullptr; try { pdata_ = new int[rownum_*colnum_]; } catch( const std::bad_alloc& ) { throw; } rownum_ = mtx.rownum_; colnum_ = mtx.colnum_; } std::copy( mtx.pdata_, mtx.pdata_+rownum_*colnum_, pdata_ ); } return *this; } CMatrix& CMatrix::operator=( CMatrix&& mtx ) noexcept { if( this != &mtx ) { rownum_ = mtx.rownum_; colnum_ = mtx.colnum_; pdata_ = mtx.pdata_; mtx.rownum_ = 0; mtx.colnum_ = 0; mtx.pdata_ = nullptr; } return *this; } CMatrix::~CMatrix() { delete[] pdata_; } int CMatrix::at( size_t row, size_t col ) const { if( row>=rownum_ || col>=colnum_ ) throw std::invalid_argument( "fuck" ); return pdata_[ row*colnum_ + col ]; } int& CMatrix::at( size_t row, size_t col ) { if( row>=rownum_ || col>=colnum_ ) throw std::invalid_argument( "fuck" ); return pdata_[ row*colnum_ + col ]; } CMatrix CMatrix::operator*( const CMatrix& mtx ) { if( rownum_==0 || colnum_==0 || mtx.rownum_==0 || mtx.colnum_==0 || colnum_!=mtx.rownum_ ) throw std::invalid_argument( "fuck" ); CMatrix ret( rownum_, mtx.colnum_ ); for( size_t row=0; row!=ret.rownum_; ++row ) { for( size_t col=0; col!=ret.colnum_; ++col ) { for( size_t k=0; k!=colnum_; ++k ) ret.at(row,col) += at(row,k)*mtx.at(k,col); } } return ret; } std::ostream& operator<<( std::ostream& os, const CMatrix& mtx ) { for( size_t r=0; r!=mtx.rownum_; ++r ) for( size_t c=0; c!=mtx.colnum_; ++c ) os << mtx.at(r,c) << (c+1==mtx.colnum_ ? '\n' : ' '); return os; } //CMatrix& CMatrix::Transpose() //{ // // 未实现，矩阵的原位转置 自己写 //} int main( void ) { CMatrix a = { 2, 3, { 1, 2, 3 , 4, 5, 6 } }; CMatrix b = { 3, 2, { 1, 4 , 2, 5 , 3, 6 } }; CMatrix c = a * b; cout << "a matrix:\n" << a << '\n'; cout << "b matrix:\n" << b << '\n'; cout << "a*b matrix:\n" << c << '\n'; //cout << "Transpose matrix:\n" << c.Transpose() << '\n'; return 0; } |
1) 编写整数矩阵运算的程序
a) 编写 2 个整数矩阵（不一定是方阵）的相乘的函数，矩阵中的元素值可以是在程序中初始化好的，也可以是随机数；
b) 编写矩阵转置的函数；
c) 编写矩阵元素输出的函数；
在 main 函数中，编写测试代码。
#include <iostream>
using namespace std;
#define MATRIX_LENTH 3
#define MATRIX_WIDRH 3
class CMatrix
{
public:
CMatrix(int Lenth ,int Width);
~CMatrix();
void OutPut();
void TransposeMatrix();
void MultiplyMatrix();
protected:
private:
int m_Lenth;
int m_Width;
int *m_pMatrix;
int *m_pAncillaryMatrix;
private:
//void Multiply
};
CMatrix::CMatrix(int Lenth ,int Width)
{
m_pMatrix = new int[Lenth*Width];
for (int i = 0; i < Lenth * Width; i++)
{
m_pMatrix[i] = rand();
}
}
CMatrix::~CMatrix()
{
delete[] m_pMatrix;
}
void CMatrix::OutPut()
{
for (int i = 0; i < m_Lenth; i++)
{
for (int j = 0; j < m_Width; j++)
{
cout<<m_pAncillaryMatrix[i][j] << " ";
}
cout << endl;
}
}
void CMatrix::TransposeMatrix()
{
for (int i = 0; i < m_Lenth; i++)
{
for (int j = 0; j < m_Width; j++)
{
m_pAncillaryMatrix[i][j] = m_pMatrix[j][i];
}
}
}
void CMatrix::MultiplyMatrix(int *InputMatrix)
{
int v1 = 0;
int v2 = 0;
for (int i = 0; i < m_Lenth; i++)
{
for (int j = 0; j < m_Width; j++)
{
for (int k = 0; k < Lenth; k++)
{
v2 = m_pMatrix[i][v1]*InputMatrix[v1++][j]
}
m_pAncillaryMatrix[i][j] = v2;
}
}
}
int main()
{
CMatrix cMatrix(MATRIX_LENTH , MATRIX_WIDTH);
int *Matrix = new int[MATRIX_LENTH*MATRIX_WIDTH];
for (int i = 0; i < MATRIX_LENTH * MATRIX_LENTH; i++)
{
m_pMatrix[i] = rand();
}
cout << "原矩阵：" << endl;
cMatrix.OutPut();
cout << "转置矩阵：" << endl;
cMatrix.TransposeMatrix();
cMatrix.OutPut();
cout << "输入矩阵：" << endl;
for (int i = 0; i < Lenth; i++)
{
for (int j = 0; j < Width; j++)
{
cout<<Matrix[i][j] << " ";
}
cout << endl;
}
cout << "相乘后的矩阵：" << endl;
cMatrix.MultiplyMatrix(Matrix);
cMatrix.OutPut();
return 0;
}