Leaf density

Leaf density --- листовая плотность.

The leaf density [math]\displaystyle{ \zeta(G) }[/math] of [math]\displaystyle{ G }[/math] is defined as

[math]\displaystyle{ \zeta(G) = \frac{l(G) - s(G)}{n}. }[/math]

Here, [math]\displaystyle{ l(G) }[/math] is the number of leaves in [math]\displaystyle{ G }[/math], [math]\displaystyle{ s(G) }[/math] is the number of stems (a vertex that is adjacent to a leaf is called a stem).