Why it is not a Huffman code I have been given several examples I the aim is to explain why it is not a Huffman code. So, for instance, the first one was:

$\{00,01,10,110\}$

This code is not Huffman becuase it has just one codeword of maximum length whereas there should be two as a minimum.

Next, the one I hava a problem in proving:

$\{01,10\}$

Why this code is not a Huffman code?
(Minimum number of codewords) (Binary complete) Huffman code of maximal code length $n$ must have at least $n+1$ codewords.

The maximal code length of codewords $\{01, 10\}$ is 2. However, there are only two codewords. So those codewords is not a Huffman code.



(Exercise.) Prove the claim of the minimum number of codewords of Huffman code.