vc0305.cpp

VC例题源代码,书本上的。。几乎是通用的

// Example 3-5：计算两个矩阵的乘积
#include <iostream.h>
// 函数matrix_multi(): 计算两个矩阵的乘积
void matrix_multi(double a[],double b[],double c[],int l,int m,int n)
{
	int i,j,k;
	for(i=0;i<l;i=i+1)
		for(j=0;j<n;j=j+1)
		{
            c[i*n+j] = 0;
        	for(k=0;k<m;k=k+1)
			c[i*n+j] += a[i*m+k]*b[k*n+j];
		}
}
// 测试上述矩阵相乘函数的主程序
void main()
{
	double a[20]=
	{
		1.0, 3.0,-2.0, 0.0, 4.0,
		-2.0,-1.0, 5.0,-7.0, 2.0,
		0.0, 8.0, 4.0, 1.0,-5.0,
		3.0,-3.0, 2.0,-4.0, 1.0
	};	
	double b[15]=
    {
		4.0, 5.0,-1.0,
		2.0,-2.0, 6.0,
		7.0, 8.0, 1.0,
		0.0, 3.0,-5.0,
		9.0, 8.0,-6.0
	};
	double c[12];
	matrix_multi(a,b,c,4,5,3);
	cout << "The result is c=" << endl;
	for(int i=0;i<4;i=i+1)
	{
		for(int j=0;j<3;j=j+1)
			cout << c[i*3+j] << "   ";
		cout << endl;
	}
}