#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<TreeNode *> fun(int start,int end )

    {

        vector<TreeNode *> ansTemp;

        vector<TreeNode *> ansTemp2;

        vector<TreeNode *> ansTemp3;

        ansTemp.clear();

        if(start>end)

        {

            ansTemp.push_back(NULL);

            return ansTemp;

        }

        if(start == end)

        {

            TreeNode *mid = new TreeNode(start);

            ansTemp.push_back(mid);

            return ansTemp;

        }

        for(int i=start;i<=end;i++)//枚举的中间位置

        {

            ansTemp2 = fun(start,i-);

            ansTemp3 = fun(i+,end);

            if(ansTemp2.size()!=&&ansTemp3.size()!=)

                for(int j = ;j<ansTemp2.size();j++)

                {

                    for(int k = ;k<ansTemp3.size();k++)

                    {

                        TreeNode * root = new TreeNode();

                        root->val = i;

                        root->left = ansTemp2[j];

                        root->right = ansTemp3[k];

                        ansTemp.push_back(root);

                    }

                }

            else if(ansTemp2.size()!=&&ansTemp3.size()==)

                for(int j = ;j<ansTemp2.size();j++)

                {

                    TreeNode * root = new TreeNode();

                    root->val = i;

                    root->left = ansTemp2[j];

                    root->right = NULL;

                    ansTemp.push_back(root);

                }

            else if(ansTemp2.size()==&&ansTemp3.size()!=)

                for(int k = ;k<ansTemp3.size();k++)

                {

                    TreeNode * root = new TreeNode();

                    root->val = i;

                    root->left = NULL;

                    root->right = ansTemp3[k];

                    ansTemp.push_back(root);

                }

            else

            {

                TreeNode * root = new TreeNode(i);

                ansTemp.push_back(root);

            }

        }

        return ansTemp;

    }

    vector<TreeNode *> generateTrees(int n) {

        // IMPORTANT: Please reset any member data you declared, as

        // the same Solution instance will be reused for each test case.

        vector<TreeNode *> ans;

        ans.clear();

        ans =  fun(,n);

        return ans;

    }

};

int main()

{

    Solution my;

    my.generateTrees();

    return ;

}