Re: Rounding a number to integer

[Dirk Laurie <dirk.laurie@...>]

2016-08-03 22:29 GMT+02:00 Egor Skriptunoff <egor.skriptunoff@gmail.com>:
>> function round(x)
>>   local ans = math.floor(x)
>>   local err = x-ans
>>   if err<0.5 then return ans
>>   elseif err>0.5 then return ans+1
>>   elseif ans%2==0 then return ans
>>   else return ans+1
>>   end
>> end
>
>
> Yes, that's correct (but cumbersome).

At least one person besides the author could see at a glance
that the code is correct. I'll take 'cumbersome' any day if it can
give me that.

> Don't you like codegolf?  :-)

Yes, but it penalizes good Lua coding (e.g. 'local' uses up
five letters and a space). I'll propose another scoring method
below :-)

> function round(x)
>    local y = math.ceil(x - 0.5)
>    return x - y + y/2%1 < 1 and y or math.ceil(x)
> end

I'll take your word that it works, since you have a good
reputation for meticulous coding.

The scoring variation is: run `luac -l` on the code and count the
number of VM instructions actually executed on input selected
to make that number as large as possible. Let the games begin!