On Saturday, March 30, 2013 8:41:08 AM UTC+10:30, Dave Angel wrote: > On 03/29/2013 05:47 PM, Eric Parry wrote: > > > > > >> <SNIP> > > >> > > > That explains why the program keeps running after a solution is found. > > > > A recursive function can be designed to find all solutions, in which > > case it would (as you say) keep running. > > > > The function you posted in the first place uses exit() to avoid keeping > > running. It stops as soon as a solution is found. > > > > Sometimes a problem cannot be solved in the number of stack entries > > supplied by Python. So even though such a function will terminate, it > > may crash first if the problem is too big. Example, the factorial > > problem I described earlier, if you pass it 2000 as a parameter. If > > this is a problem, one can tell the Python to give you more stack entries. > > > > Given a 9x9 matrix, and at least some of them filled in, the maximum > > depth your code can use is less than 81. So it won't get a stack > > overflow in any implementation of Python I've seen. Perhaps in an 8051. > > > > Sometimes a bug in such a function will cause it to run indefinitely, > > and/or to overflow the stack. I don't see such a bug in this function. > > > > > > -- > > DaveA
The exit() did not work. I replaced it with return = 0, and that does work. Eric. -- http://mail.python.org/mailman/listinfo/python-list
