  The ``state-of-the-art'' in Length Limited Huffman Coding algorithms is the
$\Theta(ND)$-time, $\Theta(N)$-space one of Hirschberg and Larmore, where $D\le
N$ is the length restriction on the code. This is a very clever, very problem
specific, technique. In this note we show that there is a simple
Dynamic-Programming (DP) method that solves the problem with the same time and
space bounds. The fact that there was an $\Theta(ND)$ time DP algorithm was
previously known; it is a straightforward DP with the Monge property (which
permits an order of magnitude speedup). It was not interesting, though, because
it also required $\Theta(ND)$ space. The main result of this paper is the
technique developed for reducing the space. It is quite simple and applicable
to many other problems modeled by DPs with the Monge property. We illustrate
this with examples from web-proxy design and wireless mobile paging.
