#include <stdio.h>
#include <math.h>
/* power.c : 1999 3 8 by Oguni */
#define N 3
main(){
  int n=3, itr[2]={20, 0};
  int i;
  double A[N][N]={1.,4.,3.,2.,5.,4.,1.,-3.,-2.};
  double x[N+1]={1.,0.,0.,0.};
  power(A,x,n,itr);
  printf("%d %f\n", itr[1], x[n]);
  for (i=0; i<n; i++){
    printf("%f\n", x[i]); }
}
/* function power */
power(A, x, n, itr)
double A[N][N], x[N+1];
int n, itr[2];
{
  int i, m;
  double c, s, lamda, xmax, y[N];
  c=0.0;
  for (i=0; i<n; i++){ c+=x[i]*x[i]; }
  for (i=0; i<n; i++){ x[i]/=sqrt(c); }
  for (m=0; m<itr[0]; m++){
    mvsub(A,x,y,n);
    s=0.0; c=0.0;
    for (i=0; i<n; i++){
      s+=y[i]*y[i]; c+=y[i]*x[i]; }
    lamda=s/c; itr[1]=m;
    if (fabs(xmax-lamda)<0.00001) return;
    xmax=lamda; x[n]=xmax;
/*    printf("%d %f\n", m, lamda); */
    for (i=0; i<n; i++){ x[i]=y[i]/sqrt(s); }
  }
  return;
}
/* multmv */
mvsub(A,b,c,n)
double A[N][N], b[N], c[N];
int n;
{
/* ŒvŽZ•”•ª */
  int i, j;
  double s;
  for (i=0; i<n; i++){
    s=0.0;
    for (j=0; j<n; j++){
      s+=A[i][j]*b[j];
    }
    c[i]=s;
  }
  return;
}