David DeSimone <[EMAIL PROTECTED]> wrote:
>> And you could avoid the division with:
>>
>> (info->lobin + info->hibin + info->ascii)*4
>> < ((info->lobin + info->hibin)*3 + info->ascii)*3
>
>But then you risk integer overflow. Which the division helps avoid, and
>in fact, floating-point helps avoid it even more. :)
Perhaps
4 * info->ascii < 5 * (info->lobin + info->hibin)
would be better. In fact, divide both sides by 5.0 to yield:
(4*info->ascii)/5.0 < info->lobin + info->hibin
Then use:
(4x)/5.0 = x - x/5 - (x%5)/5.0
and note that since 0 <= (x%5)/5.0 < 1, it follows that
0 <= x - x/5 - (4x)/5 < 1
or
(4x)/5.0 <= x - x/5 < 1 + (4x)/5.0
or
x - x/5 - 1 < (4x)/5.0 <= x - x/5
So, to avoid possible integer overflow, use the test:
info->ascii - info->ascii/5 < info->lobin + info->hibin
The analysis for info->ascii < 0 is left to the reader.
--John
