算法（7） —— 统计树的特定点

1 int CountNodes ( SearchTree T )     {
2     if ( T == NULL)
3         return 0;
4     else 
5         return 1 + CountNodes ( T->Left) + CountNodes (T->Right);
6 }

1 int CountLeaves (SearchTree T)      {
2     if  (T == NULL)
3         return 0;
4     else if (T->Left == NULL && T->Right == NULL)
5         return 1;
6     else return CountLeaves (T->Right) + CountLeaves (T -> Left);
7 }

int CountFull  (SearchTree T)    {
    if ( T == NULL)   
        return 0;
    else return (T->Right != NULL && T->Left != NULL) +
                 CountFull (T->Left) + CountFull (T->Right);
}