Re: [Dev-C++] How to work with *.txt files??

Well, don't blame yourself. The human life is meant for learning :)

Logically, there isn't a difference between a vector and an array. Vector
is the mathematical term for a one-dimensional array, i.e. an array with a
single index.

The important thing about the stl template class vector is that it doesn't
grow by one every time you add one element, which would have resulted in
O(n^2) complexity.

A typical implementation doubles the length of the vector, whenever it
needs to grow. This makes sure that the reallocation times - on average -
may be ignored, and the inserts will then run in constant amortized time,
i.e. the _average_ insert will consume constant time.

If the vector is 1,000,000 elements long - and full - and you try to
add one more entry, it grows to a length of 2,000,000 resulting in the
next one million inserts not needing any reallocation.

It really doesn't matter if a string assign if efficient or not. The
important thing to avoid - when possible - is algorithsms with exponential
growth, since the total run time will start to escalate even for extremely
fast operations.

/Per W

On Sat, 18 Sep 2004, ZwiQ wrote:

> Per Westermark wrote:
>
> > <>Ouch.
> >
> > Don't do that.
> >
> > There is the vector template class in the stl.
>
> (Hielke blames himself for not reading a good C++ book himself :o)
>
> Hm, you're right. Thanks! I said I would use a vector but in the code I
> did use an simple array. Now I think of it, the code I wrote down there
> without good thinking was ment to store an array of pointers to strings,
> not strings themselves. Used it mainly when I had to reorganize the
> order of the stored strings with manipulation members (eg. sort).
> I assume that assigning pointers isn't as resourcesconsuming as
> assigning strings? However, you're still right about the complexity.
> Vector operations themselves all are lineair? So I should use a vector
> in that case too as well?
>
> Regards,
>     Hielke
>     Zw...@he...