参照也总的
C++ 代码
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode *father;
* TreeNode(int x) : val(x), left(NULL), right(NULL), father(NULL) {}
* };
*/
class Solution {
public:
TreeNode* preNode;
TreeNode* inorderSuccessor(TreeNode* p) {
if(!p){
return NULL;
}
//有柚子树
if(p->right){
auto node=p->right;
while(node->left){
node=node->left;
}
return node;
}
//右子树不存在 只有左子树,最好结合图
while (p->father && p == p->father->right) p = p->father;
return p->father;
}
};