> With 0-based indexing the children are at 2i+1 and 2i+2. The parent is at (i-1) div 2.
> Not hard to figure out.
While that's true, "you just shift by 1" is equally good at all arguments for or against 0-based indexing, so deploying it here probably won't convince.
That said, the effort of one versus the other is so trivial that there is no point in ever using effort as an argument either way. Doubly so because what seems like effort to us is simple unfamiliarity.
What is important is which one leads to more careless errors in practice. As a trivial example, consistent indentation takes effort, but failing to do it leads to more careless errors. Therefore everyone indents code.
> Not hard to figure out.
While that's true, "you just shift by 1" is equally good at all arguments for or against 0-based indexing, so deploying it here probably won't convince.