30 Assume that F is a forest, made up of tree T1, T2, T...
单项选择题30 Assume that F is a forest, made up of tree T1, T2, T3, and the node numbers of T1, T2, T3 are n1, n2, n3 respectively. If the binary tree corresponding to F is B, there are ( ) nodes in the left subtree of B.
A.n2-1
B.n3-1
C.n1-1
D.n2