原题链接:http://oj.leetcode.com/problems/binary-tree-preorder-traversal/
题意描述:
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?
题解:
裸的二叉树遍历,没什么好说的。另外,关于二叉树,我之前做了一个还算详细的总结,这里给出链接:http://www.cnblogs.com/codershell/p/3291601.html
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 traversal(vector<int>& v,TreeNode *root){ 13 if(root==NULL) return; 14 v.push_back(root->val); 15 traversal(v,root->left); 16 traversal(v,root->right); 17 } 18 vector<int> preorderTraversal(TreeNode *root) { 19 vector<int> v; 20 21 traversal(v,root); 22 23 return v; 24 } 25 };