问题描述
Given a binary tree, return the preorder traversal of its nodes‘ values.
For example:
Given binary tree {1,#,2,3},
1 2 / 3
return [1,2,3].
Note: Recursive solution is trivial, could you do it iteratively?
解决原理
递归
代码
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 vector<int> rst; 12 public: 13 vector<int> preorderTraversal(TreeNode *root) { 14 if(root){ 15 rst.push_back(root->val); 16 preorderTraversal(root->left); 17 preorderTraversal(root->right); 18 } 19 return rst; 20 } 21 };
Q6: Binary Tree Preorder Traversal
原文：http://www.cnblogs.com/ISeeIC/p/4356152.html