In the Huffman tree with degrees m, the number of leaf nodes is n, then the number of non-leaf nodes is ().

Let's start by stating that we usually say Huffman tree is the best binary tree, also known as strict binary tree (note is not a complete binary tree), but Huffman Tree is not limited to binary tree, also exist in the multi-fork tree, that is, the degree of M Huffman Tree, also known as the optimal m fork tree, strict m fork tree (note is not a complete M-fork tree).
This question indicates that the number of nodes of Huffman tree is either 0 or M setting is not 0 (that is, non-leaf node) is X
The total node count is: X+n
Root nodes, each of the remaining nodes has a branch connected to a node, and there are m branches for each node with degrees m, and the nodes with degrees 0 are not branched, so from the point of view of the branch
Total number of nodes: X*m + 1 (here the 1 is the root node)
The two are equal, so the answer is (n-1)/(M-1)