追赶法求解方程.cpp

数值分析追赶法求解方程的源程序.使用前请仔细阅读.rar文件中readme

#include<iostream.h>
void main()
{
	long double a[]={136.01,98.810,132.01,177.17};
	long double d[]={90.860,-67.590,46.260};
	long double c[]={90.860,-67.590,46.260};
	long double b[]={-33.254,49.709,28.067,-7.3244};
	long double p[4],q[3],x[4],y[4];
	int i;
	p[0]=a[0];
	for(i=0;i<3;i++)
	{
		q[i]=c[i]/p[i];
	    p[i+1]=a[i+1]-d[i+1]*q[i];
	    //cout<<"q["<<i<<"]="<<q[i]<<endl;
	    //cout<<"p["<<i<<"]="<<q[i]<<endl;
	}
	y[0]=b[0]/p[0];
	for(i=1;i<4;i++)
	{
		y[i]=(b[i]-d[i]*y[i-1])/p[i];
	}
	x[3]=y[3];
	//cout<<"y[3]="<<y[3]<<endl;
	cout<<"x[4]="<<x[3]<<endl;//输出是按x1,x2,x3,x4形式
	for(i=2;i>=0;i--)
	{
		x[i]=y[i]-q[i]*x[i+1];
		//cout<<"y["<<i<<"]="<<y[i]<<endl;
		cout<<"x["<<i+1<<"]="<<x[i]<<endl;
	}
}