Simplest way to calculate amount of even numbers in given range

Question

What is the simplest way to calculate the amount of even numbers in a range of unsigned integers?

An example: if range is [0...4] then the answer is 3 (0,2,4)

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Answer 1

The first even number in the range is: (begin + 1) & ~1 (round begin up to even number).

The last even number in the range is: end & ~1 (round end down to even number).

The total number of even numbers in the range is therefore: (end & ~1) - ((begin + 1) & ~1) + 1.

int num_evens = (end & ~1) - ((begin + 1) & ~1) + 1;