Binary Search Tree

[plus_plus]

A binary search tree is a binary tree that has left children less than the parent and right children greater than parent. A example is like this 7
/ \
4 9

if its child is eaqual to the parent, is it still a binary tree?
7
/ \
4 7

[CarGo]

The answer is NOT.
No two entries in a binary search tree can have equal keys,since the
keys in the left subtrees are strictly smaller than the key in the
root,and those in the right subtree are strictly greater.
键值是排序的依据，不能相同，否则就不叫BST了。

[boytan]

对，二叉搜索树中不能有相同健值的节点，你看看二叉搜索树的插入算法就可以知道，它现在当前的二叉搜索树中搜索要插入的健值，如果当前二叉搜索树已经存在这个健值的节点，就return不做插入。