Binary Tree Inorder Traversal

題目：

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

For example:
Given binary tree {1,#,2,3},

   1
    \
     2
    /
   3
return [1,3,2].

代碼如下：

    void getresult(TreeNode *root,vector<int> &result)
    {
        if(root==NULL)return;
        if(root->left!=NULL)
        {
            getresult(root->left,result);
        }
        result.push_back(root->val);
        if(root->right!=NULL)
        {
            getresult(root->right,result);
        }
        return;
    }
    vector<int> inorderTraversal(TreeNode *root) {
        vector<int> result;
        getresult(root,result);
        return result;    
    }