That is to say, you cannot wrap a normal box without overlapping wrapping paper on
itself.
The question is, what is the size of rectangular wrapping paper that reduces
the amount of overlapping paper? Parts already covered don't need to be covered again!
The Algorithm
Measure the dimensions of the box. Call the shortest the height (h), the longest the
length (l), and the remaining the width (w). Cut a sheet of paper with the following
dimensions:
One side should be the height + length (h + l)
The other side should be double the height + width (2×(h + w))