題目地址：https://www.acwing.com/problem/content/87/
AC代碼
/**
* 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:
TreeNode* last=nullptr;
void inOrder(TreeNode* root){
if(!root) return;
inOrder(root->left);
root->left=last;
if(last) last->right=root;
last=root;
inOrder(root->right);
}
TreeNode* convert(TreeNode* root) {
inOrder(root);
while(root&&root->left) root=root->left;
return root;
}
};
總結(jié)
題解參考討論區(qū)
