#include "stdlib.h"
  int qrrt(n,a,xr,xi,eps,jt)
  int n,jt;
  double a[],xr[],xi[],eps;
  { int i,j;
    double *q;
    extern int qrtt();
    q=malloc(n*n*sizeof(double));
    for (j=0; j<=n-1; j++)
      q[j]=-a[n-j-1]/a[n];
    for (j=n; j<=n*n-1; j++)
      q[j]=0.0;
    for (i=0; i<=n-2; i++)
      q[(i+1)*n+i]=1.0;
    i=qrtt(n,q,xr,xi,eps,jt);
    free(q); return(i);
  }