Thread: set_intersection of two sets

set_intersection - C++ Reference
has an example of finding the set_intersection, but it declares the intersection set as

Code:

 vector<int> v(10);

why exactly we need to specify the memory, as I know vector is dynamic array, this works fine even when I don't specify for smaller set intersection but when the intersection comes out to be bigger it shows segmentation fault, How to fix it without killing the dynamic property of the vector, or is there any better way to find set intersection, its better for us to use STL library if am not wrong.

Originally Posted by Elysia

You need to use, say, a back_insert_iterator (use std::back_insert to construct one).

What is back_insert_iterator, I have used:

Code:

vector.push_back(element);

are you saying about that?

What do you mean by dynamic iterator could you give me the starting concept?

why they require enough space, how much space they require?\

Originally Posted by Elysia

you can find most of them in the <iterator> header.

Most of them?? Is there many kind of dynamic Iterators?

Then why when I used:

Code:

vector.push_back(element);

Its not working?

Originally Posted by kapil1089thekin

Then why when I used:

Code:

vector.push_back(element);

Its not working?

What I find amazing is that you tried to write this statement in the middle of a set_intersection call.

The iterator basically contains this and calls this->push_back(whatever); on a dereference operation, because it overloaded the operators the algorithm was written with. That's why a back_inserter() works and what you tried does not.