题目:
给定一棵二叉查找树和一个新的树节点,将节点插入到树中。
你需要保证该树仍然是一棵二叉查找树
样例
给出如下一棵二叉查找树,在插入节点6之后这棵二叉查找树可以是这样的:
2 2
/ \ / 1 4 --> 1 4
/ / \
3 3 6
挑战
能否不使用递归?
/** * Definition of TreeNode: * class TreeNode { * public: * int val; * TreeNode *left, *right; * TreeNode(int val) { * this->val = val; * this->left = this->right = NULL; * } * } */ class Solution { public: /* * @param root: The root of the binary search tree. * @param node: insert this node into the binary search tree * @return: The root of the new binary search tree. */ TreeNode * insertNode(TreeNode * root, TreeNode * node) { // write your code here if(root==NULL) { root=node; return node; } TreeNode* p=root; while(p!=NULL) { if(node->val<p->val) { if(p->left==NULL) { p->left=node; return root; } else { p=p->left; } } else { if(p->right==NULL) { p->right=node; return root; } else { p=p->right; } } } return NULL; } };