Inconsistency VarOptItemsSketch in C++ and Java

[proost]

1. MIN_LG_ARR_ITEMS is 3 in C++, but MIN_LG_ARR_ITEMS is 4 in Java. which one is correct? Or it depends on language?

2. C++ skips if item's weight is zero. But Java throws exception .

original paper said,

we are dealing with a stream of items where item i has a positive weight wi

So throwing exception when weight is zero, more correct to me. Are there reasons to skip in C++? (I've already saw this PR, But i can't fully understand)

cc. @jmalkin