LeetCode654. 最大二叉树

 1 class Solution {
 2 public:
 3     TreeNode* constructMaximumBinaryTree(vector<int>& nums) {
 4         //数组长度是一直接返回
 5         if(nums.size() == 1) {TreeNode *root = new TreeNode(nums[0]); return root;}
 6         //找到最大元素的位置
 7         int Index = 0;
 8         for(int i = 1;i < nums.size();i++){
 9             if(nums[Index] < nums[i]) Index = i;
10         }
11         //建立根节点
12         TreeNode *root = new TreeNode(nums[Index]);
13 
14         //分割左右树,左闭右开
15         vector<int>left(nums.begin(),nums.begin()+Index);
16         vector<int>right(nums.begin()+Index+1,nums.end());
17         
18         //递归处理左右子树
19         if(left.size()) root->left = constructMaximumBinaryTree(left);
20         if(right.size()) root->right = constructMaximumBinaryTree(right);
21 
22         return root;
23     }
24 };