remove multiple elements from vector in a loop

[LMHmedchem]

I have a vector,

std::vector<int> myVector;

myVector[0] = 3;
myVector[1] = 4;
myVector[2] = 5;

and I need to remove certain elements, in this case [1] and [2]. This is happening in a loop where some things are evaluated, and under certain circumstances, and element is removed.

for(i=0; i<myVector.size(); i++) {
   if(myVector[i] == 4 || myVector[i] == 5) {
      myVector.erase( myVector.begin()+i );
   }
}

the logic is simplified here. The output after this loop is,
myVector.size() = 2
myVector[0] = 3;
myVector[1] = 5;

As I read this, when myVector[i] == 3, control falls through and nothing happens. When myInt[i] == 4, myVector.begin()+i = 0+1 and myVector[1] is erased. When myVector[i] == 5, myVector.begin()+i = 0+2 and myVector[2] is erased. Element [2] doesn't exist anymore, so the value 5 remains on the list. Obviously I'm not using the iterator properly.

The iterator position needs to be dynamic to take into account the changing size of the vector, but I can't see how to do that. This seems like a simple issue, so I presume I am missing something here. I can't just loop through and look for 4 or 5, the logic is more complex than that. I need to know how to recursively remove elements from a vector, taking into account the fact that the vector size changes.

Maybe I need to loop differently. It's almost like I need to repeat the value of i in a case where a given i was removed. This has to work in larger vectors where the elements to be removed can occur in any element. I guess I could just set i=0 after each element is removed and repeat from the top, but that doesn't seem like the best solution either.

LMHmedchem