单选题：For the result of accessing the keys 1 and 2 in order in the spl

For the result of accessing the keys 1 and 2 in order in the splay tree in the following figure, let's define $$ \textbf{size}(v) = \text{number of nodes in subtree of } v $$ ( $$v$$ included ) and potential $$ \phi = \sum_v \lfloor \log_2 \textbf{size}(v)\rfloor$$, where $$ \lfloor x\rfloor$$ means the greatest interger no larger than $$x$$.

How many of the following statements is/are TRUE? @[C](3)
- the potential change from the **initial** tree to the **resulted** tree is -3
- 1 is the sibling of 3
- 5 is the child of 6



A. 0
B. 1
C. 2
D. 3






A.0
B.1
C.2
D.3


答案：C