学步园

#include <iostream>
#include <vector>
using namespace std;

struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};

class Solution 
{
public:
    vector<int> postorderTraversal(TreeNode *root) 
	{
        vector<int> v;
		if(!root)
        	return v;
       	vector<int> v1, v2;
       	vector<int>::iterator iter;
       	
       	v1 = postorderTraversal(root->left);
       	for(iter = v1.begin(); iter != v1.end(); ++iter)
       		v.push_back(*iter);
       		
       	v2 = postorderTraversal(root->right);
       	for(iter = v2.begin(); iter != v2.end(); ++iter)
       		v.push_back(*iter);
       		
    	v.push_back(root->val);
    	
    	return v;
	}
};

int main(void)
{
	Solution s;

	TreeNode *root = new TreeNode(1);
	TreeNode *node1 = new TreeNode(2);  root->right = node1;
	TreeNode *node2 = new TreeNode(3);  node1->left = node2;
	
	vector<int> re = s.postorderTraversal(root);
	
	vector<int>::iterator iter;
	for(iter = re.begin(); iter != re.end(); ++iter)
	{
		cout << *iter << endl;
	}
		
	return 0;
}