I couldn't find relevant answers to this online.
If I do int pos = iterator1 - iterator2
would this be an O(n) or a O(1) operation.
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I couldn't find relevant answers to this online.
If I do int pos = iterator1 - iterator2
would this be an O(n) or a O(1) operation.
Название |
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$$$O(1)$$$
To specify, I assume this is C++. For a RandomAccessIterator (for e.g. a vector) this is indeed $$$O(1)$$$. If it's a weaker form of iterator, e.g. a BidirectionalIterator from a set, then first of all it won't compile, you will need
int pos=distance(it1, it2)
and also it will be $$$O(it_2-it_1)=O(N)$$$.If you are more innterested, you can have a look at the specifications of iterators here. I think the two iterator types I named are the most common ones in CP (just my feeling).