94. Binary Tree Inorder Traversal 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> nodes;
    vector<int> inorderTraversal(TreeNode* root) {
        nodes.clear();
        inorder(root);
        return nodes;
    }
    void inorder(TreeNode* root)//其它遍历类似，只改变一下顺序即可
    {
    	if(root == NULL)return ;
    	inorder(root->left);
    	nodes.push_back(root->val);
    	inorder(root->right);
    }
};