我的解题
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
/**
* @brief 左闭右闭
*
* @param nums
* @param left
* @param right
* @return
*/
int max_index(vector<int> &nums, int left, int right)
{
int max_i = left;
for (int i = left + 1; i <= right; ++i)
{
if (nums[i] > nums[max_i])
{
max_i = i;
}
}
return max_i;
}
TreeNode* constructMaximumBinaryTree(vector<int> &nums)
{
return constructMaximumBinaryTree(nums, 0, nums.size() - 1);
}
TreeNode* constructMaximumBinaryTree(vector<int> &nums, int left, int right)
{
if (left <= right)
{
int max_i = max_index(nums, left, right);
TreeNode *root = new TreeNode { nums[max_i] };
root->left = constructMaximumBinaryTree(nums, left, max_i - 1);
root->right = constructMaximumBinaryTree(nums, max_i + 1, right);
return root;
}
else
{
return nullptr;
}
}
};
// g++ test.cpp --std=c++11 -pedantic -Wall -Wextra -g