more than 36 distinct symbols (it runs out of alphanumerics), check
this in validate_params. I hate to do this, since I like puzzle
sizes to at least be open-ended in _principle_, but in this case
there's a fundamental UI limitation which won't be fixed by getting
a faster CPU.
[originally from svn r6098]
return "Both dimensions must be at least 2";
if (params->c > ORDER_MAX || params->r > ORDER_MAX)
return "Dimensions greater than "STR(ORDER_MAX)" are not supported";
+ if ((params->c * params->r) > 36)
+ return "Unable to support more than 36 distinct symbols in a puzzle";
return NULL;
}