Given a binary tree, return the postorder traversal of its nodes' values.

For example:

Given binary tree {1,#,2,3},

1    \     2    /   3

 

return [3,2,1].

Note: Recursive solution is trivial, could you do it iteratively?

 

Code:

class Solution {public:    void findNode(vector
     
       &nodes,TreeNode *node){        if(node->left)            findNode(nodes,node->left);        if(node->right)            findNode(nodes,node->right);        nodes.push_back(node->val);        return;    }        vector
      
        postorderTraversal(TreeNode *root) {        vector
       
         nodes;        if(!root) return nodes;        findNode(nodes,root);        return nodes;    }};