1 /**
2 * Definition for binary tree
3 * struct TreeNode {
4 * int val;
5 * TreeNode *left;
6 * TreeNode *right;
7 * TreeNode(int x) : val(x), left(NULL), right(NULL) {}
8 * };
9 */
10 class Solution {
11 public:
12 void preOr(TreeNode * node, vector<int> & rlt){
13 if (node==NULL)
14 return;
15 rlt.push_back(node->val);
16 preOr(node->left,rlt);
17 preOr(node->right,rlt);
18 }
19 vector<int> preorderTraversal(TreeNode *root) {
20 // IMPORTANT: Please reset any member data you declared, as
21 // the same Solution instance will be reused for each test case.
22 vector<int> rlt;
23 preOr(root, rlt);
24 return rlt;
25 }
26 };
