1 //1 二叉树的深度(在后序遍历的基础上进行 时间复杂度: O(n)) (即左右子树的最大深度加1)
 2 public int getDepth(BiTNode node)
 3 {
 4     if(node == null)
 5     return 0;
 6 
 7     int count1, count2;
 8     count1 = getDepth(node.lchild);
 9     count2 = getDepth(node.rchild);
10     return max(count1, count2) + 1;
11 }
 
 1 //2 给定结点的后继(Successor)
 2 public BiNode Successor(BiNode x)
 3 {
 4     BiNode p = x.rchild;
 5     if(p != null)
 6     {
 7         while(p.lchild != null)
 8             p = p.lchild;
 9         return p;
10     }
11     BiNode q = x.parent;
12     while(q != null && x == q.rchild)
13     {
14         x = q;
15         q = q.parent;
16     }
17     return q;
18 }
 
 1 //3 给定结点的前驱(Predecessor)
 2 public BiNode Predecessor(BiNode x)
 3 {
 4     BiNode p = x.lchild;
 5     if(p != null)
 6     {
 7         while(p.rchild != null)
 8             p = p.rchild;
 9         return p;
10     }
11     BiNode q = x.parent;
12     while(q != null && x == q.lchild)
13     {
14         x = q;
15         q = q.parent;
16     }
17     return q;
18 }