Iterate over vector efficently

Question

I want to iterate over a vector of an custom structure "Edge". I have sorted the vector beforehand for the attribute weight. Sometimes I want to stop iterating over the vector, calculate other stuff. When I iterate over the vector again, I want to start at the last visited element.

Example with Integers: Edge : [0,1,2,3,4,5,6] Iterate: 0,1,2 Break out of function and calculate other stuff Iterate: [3,4,5,6]

I thought about saving a vector::iterator. It would be easier to change the pointer to the first element to the wanted element instead but I didn't found anything for this

Thanks.

Be aware that vector iterators are particularly vulnerable to being invalidated if the vector is resized at all. — Gem Taylor, Jul 17 '18 at 17:48
This question has absolutely nothing to do with the "duplicate marked" question. This is great. — Zwuedus, Jul 20 '18 at 12:54

Gabriel · Answer 1 · 2018-07-17T19:20:33.117

1

Try something like this:

for(int i = 0; i < vec.size(); i++) {
     do_work(vec[i]);
     if(i == breakPoint) {
         do_calculations();
     }
}

Where breakPoint is an int indicating the index at which you want to stop. Unless, breaking the function is really important. Then you could use a static i, but that has the potential to give you more of a headache than I think it's worth

edited Jul 17 '18 at 19:20

answered Jul 17 '18 at 17:48

Gabriel

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Iterate over vector efficently

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