Alan Gauld schreef:
On 09/12/13 13:48, spir wrote:
On 12/09/2013 02:29 PM, Wolfgang Maier wrote:
spir <denis.spir <at> gmail.com> writes:

Tu sum it up (aha!): you algorithm is the right and only one
No, it's not the only one. ...
also the pure numbers approach pointed out by me and Alan.
You are right in a sense, but this is what int() does, isn't it?

No. int() can be done in several ways but usually it's based on taking the character code and adding/subtracting some base value. (or uses a lookup table). But to get the individual characters for conversion it will loop over a string so in that respect its similar to the string based approaches. But the OP didn't start with a string, he started with an int.

spir should have said "..., but this is what str() does, ..." I think.

Extracting the individual digits from the number is the core of both algorithms, and I would think str() uses an algorithm similar to the divmod() approach (but in C instead of Python, possible simply using the relevant function from the C standard library).

The difference is that str() converts the digits to chars (which have to be converted back to ints later) while the pure divmod() approach doesn't do that.

All in all I think the two algorithms don't differ that much, the main difference being that in the str() approach part of the algorithm is hidden behind the str() call.



--
"Met een spitsvondig citaat bewijs je niets."
        -- Voltaire

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