Python supports a third way: start at -1. And if you think about it a little (but not too much) then there's some real appeal to it in C. If you allocate an a

Python supports a third way: start at -1. And if you think about it a little (but not too much) then there's some real appeal to it in C. If you allocate an array of length n and store its length and rewrite the pointer with (*a+=n)=n, then a[0] is the length, a[-1] is the first element (etc) and you free(a-a[0]) when you're done. As a nice side effect, certain tracing garbage collectors will never touch arrays stored in this manner. Upshot: if you take the above seriously (proposed by Kelly Boothby), the median proposed by Kelly-Bootle returns to the only sensible choice: zero.