bool operator==(const bigint &lhs, const std::string &rhs)
{
	std::string slhs = lhs.dtos(lhs.deq);
	return (slhs == rhs);
}

 friend bigint gcd(const bigint &a, const bigint &b) {
     return b.isZero() ? a : gcd(b, a % b);
 }

//.........这里部分代码省略.........
      } else if (endswith(outfilename, ".mc")) {
         outputismc = 1 ;
#ifdef ZLIB
      } else if (endswith(outfilename, ".rle.gz")) {
         outputgzip = 1 ;
      } else if (endswith(outfilename, ".mc.gz")) {
         outputismc = 1 ;
         outputgzip = 1 ;
#endif
      } else {
         lifefatal("Output filename must end with .rle or .mc.") ;
      }
      if (strlen(outfilename) > 200)
         lifefatal("Output filename too long") ;
   }
   if (timeline && hyper)
      lifefatal("Cannot use both timeline and exponentially increasing steps") ;
   imp = createUniverse() ;
   if (progress)
      lifeerrors::seterrorhandler(&progerrors_instance) ;
   else
      lifeerrors::seterrorhandler(&stderrors_instance) ;
   if (verbose) {
      hlifealgo::setVerbose(1) ;
   }
   imp->setMaxMemory(maxmem) ;
#ifdef TIMING
   timestamp() ;
#endif
   if (testscript) {
      if (argc > 1) {
         filename = argv[1] ;
         const char *err = readpattern(argv[1], *imp) ;
         if (err) lifefatal(err) ;
      }
      runtestscript(testscript) ;
   }
   filename = argv[1] ;
   const char *err = readpattern(argv[1], *imp) ;
   if (err) lifefatal(err) ;
   if (liferule) {
      err = imp->setrule(liferule) ;
      if (err) lifefatal(err) ;
   }
   bool boundedgrid = (imp->gridwd > 0 || imp->gridht > 0) ;
   if (boundedgrid) {
      hyper = 0 ;
      inc = 1 ;     // only step by 1
   }
   if (inc != 0)
      imp->setIncrement(inc) ;
   if (timeline) {
      int lowbit = inc.lowbitset() ;
      bigint t = 1 ;
      for (int i=0; i<lowbit; i++)
         t.mul_smallint(2) ;
      if (t != inc)
         lifefatal("Bad increment for timeline") ;
      imp->startrecording(2, lowbit) ;
   }
   int fc = 0 ;
   for (;;) {
      if (quiet < 2) {
         cout << imp->getGeneration().tostring() ;
         if (!quiet)
            cout << ": " << imp->getPopulation().tostring() << endl ;
         else
            cout << endl ;
      }
      if (popcount)
         imp->getPopulation() ;
      if (autofit)
        imp->fit(viewport, 1) ;
      if (render)
        imp->draw(viewport, renderer) ;
      if (maxgen >= 0 && imp->getGeneration() >= maxgen)
         break ;
      if (!hyper && maxgen > 0 && inc == 0) {
         bigint diff = maxgen ;
         diff -= imp->getGeneration() ;
         int bs = diff.lowbitset() ;
         diff = 1 ;
         diff <<= bs ;
         imp->setIncrement(diff) ;
      }
      if (boundedgrid && !imp->CreateBorderCells()) break ;
      imp->step() ;
      if (boundedgrid && !imp->DeleteBorderCells()) break ;
      if (timeline) imp->extendtimeline() ;
      if (maxgen < 0 && outfilename != 0)
         writepat(fc++) ;
      if (timeline && imp->getframecount() + 2 > MAX_FRAME_COUNT)
         imp->pruneframes() ;
      if (hyper)
         imp->setIncrement(imp->getGeneration()) ;
   }
   if (maxgen >= 0 && outfilename != 0)
      writepat(-1) ;
   exit(0) ;
}

 void to_bigint(string &s, bigint &n) {
     for (int i = s.size()-1; i >= 0; i--) {
         n.push_back(s[i] - '0');
     }
 }

void doresize(bigint &ret, const bigint &lhs, const bigint &rhs)
{
	unsigned int size = rhs.getWidth() > lhs.getWidth() ? rhs.getWidth() : lhs.getWidth();
	if (ret.getWidth() < size)
		ret.resize(size);
}

str
export_srp_params (const bigint &N, const bigint &g)
{
  return strbuf ("N=0x") << N.getstr (16) << ",g=0x" << g.getstr (16);
}