你能说清楚以下定义在树中元素上的操作哪些 是基本操作B)？哪些是特殊操作(S)吗？ procedure initialise (var T:tree); B (This procedure returns an empty tree * function empty (T:tree):boolean; (If T is empty a true value is returned,otherwise a false B value is returned * function root (T:tree):node; (If T is empty,this function returns a null node.For non-empty trees T, S the root node of the tree T will be returned * function retrieve(N:node):elemtype; (This function returns the element stored in node N*) B function parent (N:node):node; (This function returns the parent node of N. S If N has no parent,a null node will be returned *你能说清楚以下定义在树中元素上的操作哪些 是基本操作(B)？哪些是特殊操作(S)吗？ B B B S S