The construction of Huffman codes is a submodular (“convex”) optimization problem over a lattice of binary trees

D. Stott Parker Jr. and Prasad Ram
SIAM J. Computing 28(5):1875–1905, 1999

Cites:

Fano Experimental Web Server, D. Eppstein, School of Information & Computer Science, UC Irvine
Made on a Mac Valid XHTML 1.0!