/*
 * Copyright © 2002  Bart Massey.
 * All Rights Reserved.  See the file COPYING in this directory
 * for licensing information.
 */
bool[*] make_sieve(int size) {
  bool[size] sieve = {true ...};
  for (int k = 2; k < size; k++) {
    if (!sieve[k])
      continue;
    for (int i = 2 * k; i < size; i += k)
      sieve[i] = false;
  }
  return sieve;
}