#include<iostream.h>
#include<math.h>

void seidel(double a[4][4],double b[4],double x[4],double pe)
{ 	int i,j,n=4;
	double t,e,temp;
 for(i=0;i<n;i++)
			x[i]=0;
		do
		{
			e=0;
			for(i=0;i<n;i++)
			{
				t=x[i];
				temp=0;
				for(j=0;j<n;j++)
					if(j!=i) temp+=a[i][j]*x[j];
				x[i]=(b[i]-temp)/a[i][i];
				if(fabs(x[i]-t)>e) e=fabs(x[i]-t);
			}
		}while(e>pe);
		cout<<"結果為:\n";
		for(i=0;i<n;i++)
			cout<<"x"<<i+1<<"="<<x[i]<<"\n";


}
	void main()
	{
		cout<<"gauss-seidel迭代法解線性方程組:\n";
		double a[4][4]={-4,1,1,1,1,-4,1,1,1,1,-4,1,1,1,1,-4};
		double b[4]={1,1,1,1};
		double x[4],pe=0.0000001;
        seidel(a,b,x,pe);
		
}