leetcode

0 class Solution {

1 TreeNode *root;

2 TreeNode *find(int k) {

3 TreeNode *t = root;

4 while (t && t->val != k)

5 t = t->val > k ? t->left : t->right;

6 return t;

7 }

8

9 public:

10 bool findTarget(TreeNode *root, int k) {

11 stack<TreeNode *> st;

12 st.push(this->root = root);

13 while (!st.empty()) {

14 TreeNode *t, *root = st.top();

15 st.pop();

16 while (root) {

17 if ((t = find(k - root->val)) && t != root) return true;

18 if (root->right) st.push(root->right);

19 root = root->left;

20 }

21 }

22 return false;

23 }

24 };