遞歸

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 n) { 13 return dfs(1,n); 14 } 15 vector<TreeNode *> dfs(int l,int r) 16 { 17 vector<TreeNode *> res; 18 if(l > r) 19 { 20 res.push_back(NULL); 21 return res; 22 } 23 vector<TreeNode *> left; 24 vector<TreeNode *> right; 25 for(int cur = l ; cur <= r ; ++cur) 26 { 27 left = dfs(l,cur-1); 28 right = dfs(cur+1,r); 29 for(int i = 0 ; i < left.size() ; ++i) 30 { 31 for(int j = 0 ; j < right.size() ; ++j) 32 { 33 TreeNode *root = new TreeNode(cur); 34 root->left = left[i]; 35 root->right = right[j]; 36 res.push_back(root); 37 } 38 } 39 } 40 return res; 41 } 42 };

?

轉載于:https://www.cnblogs.com/cane/p/3967785.html

總結

以上是生活随笔為你收集整理的LeetCode-- Unique Binary Search Trees II的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。