gauss-seidel.cpp

Gauss-Seidel

#include<iostream.h>
int jiefangchengzu(int,int);
int main()
{
	int f,n=0;
	cout<<"输入方程组的阶数:"<<endl;
	cin>>f;
	n=jiefangchengzu(n,f);
	cout<<"迭代次数n="<<n<<endl;
	return 0;
}
int jiefangchengzu(int n,int f)
{
	long double **a,*b,*x;
    long double c=1,d=0,e=0;
	a=new long double*[f];
	for(int l=0;l<f;l++)
		a[l]=new long double[f];
	b=new long double[f];
	x=new long double[f];
	cout<<"请输入矩阵系数a和b:"<<endl;
	for(int t=0; t<f; t++)
	{
		for(int j=0; j<f; j++)
			cin>>a[t][j];
		cout<<"b["<<t<<"]=";
		cin>>b[t];
		x[t]=0;
	}
	while(c>0.0000000001)
	{
		c=0;
		n++;
		for(int p=0; p<f; p++)
		{
			d=0;
			for(int q=0; q<f; q++)
			{
				if(p==q)
					continue;
				d=d+a[p][q]*x[q];
			}
			e=x[p];
			x[p]=(b[p]-d)/a[p][p];
			if((e-x[p])>=0.0000000001)
				c=e-x[p];
			if((e-x[p])<=-0.0000000001)
				c=x[p]-e;
		}
	}
	cout<<"解向量为:"<<endl;
    for(int g=0; g<f;g++)
		cout<<x[g]<<endl;
	return n; 
}