Re: How to remove elements of vector by index

From:

Ondra Holub <ondra.holub@post.cz>

Newsgroups:

comp.lang.c++

Date:

Mon, 23 Jul 2007 04:06:00 -0700

Message-ID:

<1185188760.257334.29350@g4g2000hsf.googlegroups.com>

On 23 ec, 12:19, Angus <anguscom...@gmail.com> wrote:

Hello

I have a vector<int> (aRemovecoll) which is a list of the indexes to
be removed from another vector. The other vecotr contains an object -
I will call it SomeObject. So the other vecotr is a
vector<SomeObject>.

I have created a function like this so far:

    UINT uNumElements = aRemoveColl.GetSize();
    vector<T>::reverse_iterator obCurrent = rbegin(); // work from
end back
    for (UINT nLoop = uNumElements; nLoop != 0; nLoop--)
    {
        // Work from end of vecotr to beginning so that iterators are
always valid
        intuIndex;
        aRemoveColl.GetAt(nLoop, uIndex);
        advance(obCurrent, uIndex);
        erase(obCurrent);
    }

My thinking is that I need to erase from the end backwards because
otherwise the iterator will become invalid. But then advance doesn't
see right. Is there a backward? Or should I be doing this totally
differently?

Hi.

You can use iterators, for example:
std::vector<int> v;

// Here fill v with some values
// ...

v.erase(v.begin() + 4, v.begin() + 10); // Removes elements from index
4 to 10