1 /**
2 * Definition for binary tree
3 * struct TreeNode {
4 * int val;
5 * TreeNode *left;
6 * TreeNode *right;
7 * TreeNode(int x) : val(x), left(NULL), right(NULL) {}
8 * };
9 */
10 class Solution {
11 public:
12 vector <TreeNode *> generateTrees(int min, int max){
13 if (min>max){
14 TreeNode * tmp = NULL;
15 return vector<TreeNode*>(1,tmp);
16 }
17 vector<TreeNode *> rlt;
18 for (int i=min; i<=max; i++){
19 vector<TreeNode*> left_nodes = generateTrees(min, i-1);
20 int lsize = left_nodes.size();
21 vector<TreeNode*> right_nodes = generateTrees(i+1,max);
22 int rsize = right_nodes.size();
23 for (int j=0; j<lsize; j++)
24 for (int k=0; k<rsize; k++){
25 TreeNode * node = new TreeNode(i);
26 node->left = left_nodes[j];
27 node->right = right_nodes[k];
28 rlt.push_back(node);
29 }
30 }
31 return rlt;
32 }
33 vector<TreeNode *> generateTrees(int n) {
34 // IMPORTANT: Please reset any member data you declared, as
35 // the same Solution instance will be reused for each test case.
36 return generateTrees(1,n);
37 }
38 };
