leetcode Unique Binary Search Trees II

参考博客



http://blog.csdn.net/linhuanmars/article/details/24761437

代码

class Solution {public:    vector<TreeNode *> generateTrees(int n) {        vector<TreeNode *> result;        TreeNode *oneTreeNode = new TreeNode(0);;                if(n==0)            return result;        if(n==1)        {            oneTreeNode->val = 1;            return result.push_back(oneTreeNode);        }                generateTreesHelper(result, oneTreeNode, n);                return result;            }        void generateTreesHelper( vector<TreeNode *> &result, TreeNode *oneTreeNode, int n)    {                for(int i = 3; i <= n; ++i)        {            TreeNode *node = new TreeNode(i);            node->left =             for(int j = 0; j < i; ++j)            {                 generateTreesHelper(result, oneTreeNode, j);            }                    }            }};