text: // Copyright (c) 2018, The Safex Project
  // 
  // All rights reserved.
  // 
  // Redistribution and use in source and binary forms, with or without modification, are
  // permitted provided that the following conditions are met:
  // 
  // 1. Redistributions of source code must retain the above copyright notice, this list of
  //    conditions and the following disclaimer.
  // 
  // 2. Redistributions in binary form must reproduce the above copyright notice, this list
  //    of conditions and the following disclaimer in the documentation and/or other
  //    materials provided with the distribution.
  // 
  // 3. Neither the name of the copyright holder nor the names of its contributors may be
  //    used to endorse or promote products derived from this software without specific
  //    prior written permission.
  // 
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
  // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
  // THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
  // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  // 
  // Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
  // Parts of this file are originally copyright (c) 2014-2018 The Monero Project
  
  #include <cstdint>
  #include <cstdlib>
  #include <cstring>
  #include <limits>
  #include "crypto/hash.h"
  #include "cryptonote_basic/difficulty.h"
  
  using namespace std;
  using cryptonote::check_hash;
  
  int main(int argc, char *argv[]) {
    crypto::hash h;
    for (uint64_t diff = 1;; diff += 1 + (diff >> 8)) {
      for (uint16_t b = 0; b < 256; b++) {
        memset(&h, b, sizeof(crypto::hash));
        if (check_hash(h, diff) != (b == 0 || diff <= 255 / b)) {
          return 1;
        }
        if (b > 0) {
          memset(&h, 0, sizeof(crypto::hash));
          ((char *) &h)[31] = b;
          if (check_hash(h, diff) != (diff <= 255 / b)) {
            return 1;
          }
        }
      }
      if (diff < numeric_limits<uint64_t>::max() / 256) {
        uint64_t val = 0;
        for (int i = 31; i >= 0; i--) {
          val = val * 256 + 255;
          ((char *) &h)[i] = static_cast<char>(val / diff);
          val %= diff;
        }
        if (check_hash(h, diff) != true) {
          return 1;
        }
        if (diff > 1) {
          for (int i = 0;; i++) {
            if (i >= 32) {
              abort();
            }
            if (++((char *) &h)[i] != 0) {
              break;
            }
          }
          if (check_hash(h, diff) != false) {
            return 1;
          }
        }
      }
      if (diff + 1 + (diff >> 8) < diff) {
        break;
      }
    }
    return 0;
  }
  