インタビューの質問04.02。最小の高さツリー
アイデア:dfs、左側のサブツリー、右側のサブツリー
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
TreeNode* sortedArrayToBST(vector<int>& nums) {
return dfs(nums, 0, nums.size()-1);
}
private:
TreeNode* dfs(vector<int>& nums, int l, int r){
if(l>r) return NULL;
int mid = (l+r)/2;
TreeNode* root = new TreeNode(nums[mid]);
root->left = dfs(nums, l, mid-1);
root->right = dfs(nums, mid+1, r);
return root;
}
};