/*
  Author:  Pate Williams (c) 1997

  Algorithm 5.3.5 (h(D) Counting Reduced Forms).
  See "A Course in Computational Algebraic Number
  Theory" by Henri Cohen page 223.
*/

#include <stdio.h>
#include "lip.h"

void h(verylong zD, verylong *zh)
{
  verylong zB = 0, za = 0, zb = 0, zc = 0, zq = 0;
  verylong zr = 0, zs = 0;

  zone(zh);
  zintoz(zsmod(zD, 2l), &zb);
  zcopy(zD, &za);
  zabs(&za);
  zsdiv(za, 3l, &zc);
  zsqrt(zc, &zB, &za);
  L2:
  zsq(zb, &za);
  zsub(za, zD, &zc);
  zsdiv(zc, 4l, &zq);
  zcopy(zb, &za);
  if (zscompare(za, 1l) <= 0) {
    zone(&za);
    goto L4;
  }
  L3:
  zmod(zq, za, &zr);
  if (zscompare(zr, 0l) == 0) {
    zsq(za, &zc);
    if (zcompare(za, zb) == 0 || zcompare(zc, zq) == 0 ||
        zscompare(zb, 0l) == 0) {
      zsadd(*zh, 1l, &zc);
      zcopy(zc, zh);
    }
    else {
      zsadd(*zh, 2l, &zc);
      zcopy(zc, zh);
    }
  }
  L4:
  zsadd(za, 1l, &zc);
  zcopy(zc, &za);
  zsq(za, &zc);
  if (zcompare(zc, zq) <= 0) goto L3;
  zsadd(zb, 2l, &zc);
  zcopy(zc, &zb);
  if (zcompare(zb, zB) <= 0) goto L2;
  zfree(&zB);
  zfree(&za);
  zfree(&zb);
  zfree(&zc);
  zfree(&zq);
  zfree(&zr);
  zfree(&zs);
}

int main(void)
{
  verylong zD = 0, za = 0, zh = 0;

  zintoz(- 79l, &zD);
  printf(" D  h\n");
  while (zscompare(zD, 0l) < 0) {
    h(zD, &zh);
    printf("%3ld %ld\n", ztoint(zD), ztoint(zh));
    zsadd(zD, 1l, &za);
    zcopy(za, &zD);
  }
  zfree(&zD);
  zfree(&za);
  zfree(&zh);
  return 0;
}