94. Binary Tree Inorder Traversal

简单题， 中序遍历

/** * Definition for a binary tree node. * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public:    vector<int>ve;    void getit(TreeNode* root){        if(root == NULL) return ;        getit(root -> left);        ve.push_back(root -> val);        getit(root -> right);    }    vector<int> inorderTraversal(TreeNode* root) {        getit(root);        return ve;    }};