Example 1:
Input: [5,3,6,2,4,null,8,1,null,null,null,7,9]
5
/ \
3 6
/ \ \
2 4 8
/ / \
1 7 9
Output: [1,null,2,null,3,null,4,null,5,null,6,null,7,null,8,null,9]
1
\
2
\
3
\
4
\
5
\
6
\
7
\
8
\
9
編譯碼:
/**
* 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:
void myfun(TreeNode* root, TreeNode** prev)
{
if (!root)
return;
myfun(root->right, prev);
root->right=*prev;
*prev =root;
myfun(root->left,prev);
root->left =NULL;
}
TreeNode* increasingBST(TreeNode* root)
{
TreeNode* prev =NULL;
myfun(root, &prev);
return prev;
}
};
