pythonize this!

[Xavier Ho]

On 15 June 2010 22:55, superpollo <utente at esempio.net> wrote:

> Peter Otten ha scritto:
>
>  superpollo wrote:
>>
>>  goal (from e.c.m.): evaluate
>>> 1^2+2^2+3^2-4^2-5^2+6^2+7^2+8^2-9^2-10^2+...-2010^2, where each three
>>> consecutive + must be followed by two - (^ meaning ** in this context)
>>>
>>
>>  from itertools import cycle, izip
>>>>> sum(sign*i*i for sign, i in izip(cycle([1]*3+[-1]*2), range(1, 2011)))
>>>>>
>>>> 536926141
>>
>
> don't understand it bit i like this a lot!


Peter's solution is really identical as mine, except he used a generator and
I used a modulo operator.

Cheers,
Xav
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