d1r4.cpp

VC++常用数据算法集,里面包含了大量的常用算法程序,很有用的哟!

#include "iostream.h"
#include "math.h"

void main()
{
    //program d1r4
    //driver program for routine pendag
    int i,j,l,n = 7;
    double a[8],b[8],c[8],d[8],e[8],r[8],u[8],a1[8][8],x[8];
    //输入已知的方程组的系数矩阵
    for (i = 1; i<=n; i++)
	{
        for (j = 1; j<=n; j++)
		{
			a1[i][j] = 0;
        }
    }
    a1[1][1]=4; a1[1][2]=1; a1[1][3]=1;
    a1[2][1]=1; a1[2][2]=5; a1[2][3]=2; a1[2][4]=2;
    a1[3][1]=1; a1[3][2]=2; a1[3][3]=6; a1[3][4]=3; a1[3][5]=3;
    a1[4][2]=2; a1[4][3]=3; a1[4][4]=7; a1[4][5]=4; a1[4][6]=4;
    a1[5][3]=3; a1[5][4]=4; a1[5][5]=8; a1[5][6]=5; a1[5][7]=5;
    a1[6][4]=4; a1[6][5]=5; a1[6][6]=9; a1[6][7]=6;
    a1[7][5]=5; a1[7][6]=6; a1[7][7]=10;
    //输入已知的方程组的右端向量
    r[1] = 1;    r[2] = 2;    r[3] = 3;
    r[4] = 4;    r[5] = 5;    r[6] = 6;
    r[7] = 7;
    cout<<endl;
    cout<<"已知的方程组的右端向量"<<endl;
	cout.width(10);    cout<<r[1]<<endl;
	cout.width(10);    cout<<r[2]<<endl;
	cout.width(10);    cout<<r[3]<<endl;
	cout.width(10);    cout<<r[4]<<endl;
	cout.width(10);    cout<<r[5]<<endl;
	cout.width(10);    cout<<r[6]<<endl;
	cout.width(10);    cout<<r[7]<<endl;
    for (i = 3; i<=n; i++)
	{
        a[i] = a1[i][i - 2];
    }
    for (i = 2; i<=n; i++)
	{
        b[i] = a1[i][i - 1];
    }
    for (i = 1; i<=n-1; i++)
	{
        d[i] = a1[i][i + 1];
    }
    for (i = 1; i<=n-2; i++)
	{
        e[i] = a1[i][i + 2];
	}
    for (i = 1; i<=n; i++) 
	{
        c[i] = a1[i][i];
    }
    pendag(a, b, c, d, e, r, u, n);
    cout<<endl;
    cout<<"计算出的方程组的解"<<endl;
	cout.width(14);    cout<<u[1]<<endl;
	cout.width(14);    cout<<u[2]<<endl;
	cout.width(14);    cout<<u[3]<<endl;
	cout.width(14);    cout<<u[4]<<endl;
	cout.width(14);    cout<<u[5]<<endl;
	cout.width(14);    cout<<u[6]<<endl;
	cout.width(14);    cout<<u[7]<<endl;
    //将计算出的解乘以系数矩阵，以验证计算结果正确
    for (l = 1; l<=n; l++)
	{
        x[l] = 0.0;
        for (j = 1; j<=n; j++)
		{
            x[l] = x[l] + a1[l][j] * u[j];
        }
    }
    cout<<endl;
    cout<<"计算出的解乘以系数矩阵的结果"<<endl;
	cout.width(10);    cout<<x[1]<<endl;
	cout.width(10);    cout<<x[2]<<endl;
	cout.width(10);    cout<<x[3]<<endl;
	cout.width(10);    cout<<x[4]<<endl;
	cout.width(10);    cout<<x[5]<<endl;
	cout.width(10);    cout<<x[6]<<endl;
	cout.width(10);    cout<<x[7]<<endl;
}