gause－seidel.h

很有用的算法哦。这是我好不容易

/*#include<iosteam.h>
void G_S(){
	int n;
	int j,i,k,r;
	float temp=0;
	float esp=0.00001;
	cout<<"输入矩阵的阶数:";
	cin>>n;
	float A[N][N];
	float *b=new float[n];
	float *x=new float[n];
	for(i=0;i<n;i++){
	    cout<<"输入矩阵的第"<<i+1<<"行:";
	    for(j=0;j<n;j++)
			cin>>A[i][j];
	}
	cout<<"输入矩阵的右值:";
	for(i=0;i<n;i++){
		cin>>b[i];
	}
	cout<<"输入初始值:";
	for(i=0;i<n;i++){
		cin>>x[i];
	}
	////////////////////////////////////
	do{
	for(i=0;i<n;i++){
		temp=b[i];
		for(j=0;j<n;j++){
			if(j!=i)temp-=A[i][j]*x[j];
			x[i]=temp/A[i][i];
		}
	}while(
	for(k=0;k<n;k++)cout<<x[i]<<' ';
	cout<<endl;
}*/
#include<math.h>
#include<iostream.h>
  int gausdl(n,a,b,x,eps)
  int n;
  double a[],b[],x[],eps;
  { int i,j,u,v;
    double p,t,s,q;
    for (i=0; i<=n-1; i++)
      { u=i*n+i; p=0.0; x[i]=0.0;
        for (j=0; j<=n-1; j++)
          if (i!=j)
            { v=i*n+j; p=p+fabs(a[v]);}
        if (p>=fabs(a[u]))
          { printf("fail\n"); return(-1);}
      }
    p=eps+1.0;
    while (p>=eps)
      { p=0.0;
        for (i=0; i<=n-1; i++)
          { t=x[i]; s=0.0;
            for (j=0; j<=n-1; j++)
              if (j!=i) s=s+a[i*n+j]*x[j];
            x[i]=(b[i]-s)/a[i*n+i];
            q=fabs(x[i]-t)/(1.0+fabs(x[i]));
            if (q>p) p=q;
          }
      }
    return(1);
  }