Re: A little of coordination for Rosettacode

[Andrea Fontana]

On Tuesday, 19 March 2013 at 15:55:19 UTC, ixid wrote:

I was just looking at the Rosetta code for prime decomposition and it seems bugged to me, wanted to make sure as you seem to be the one coordinating these things:

http://rosettacode.org/wiki/Prime_decomposition#D

This will potentially return a 1 in the list of primes which is a bug as 1 isn't prime.

You're right. I think the right code for decompose is this:

T[] decompose(T)(T n) /*pure nothrow*/ {
        T[] res;
        for (T i = 2; n % i == 0;) {
                res ~= i;
                n /= i;
        }
        for (T i = 3; n != 1; i += 2) { // ----- Changed condition
                while (n % i == 0) {
                        res ~= i;
                        n /= i;
                }
        }
        // ----- Removed concat here
        return res;
}