[Tutor] Testing if a number occurs more than once

[alan.gauld@bt.com]

> Jeff Shannon (and a similar one--I think!--from Alan Gauld)
> -----------------------------------------------------------
> res = {}
> for item in l:
>    if res.get(item, 0):
>      res[item] = 1
>    else:
>      return 1
> return 0

I posted a more inefficient version using dictionaries 
but looping twice. I actually thought of the solution above 
today and was just going to post it when I saw the latest 
digest...

Ah well, at least we got there even if not directly necessary 
for your requirement.

Alan G