二叉树定义

1.定义

#c++ 
 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) {}
 };
 
 
#python
class TreeNode:
    def __init__(self,value):
        self.value = value
        self.left = None
        self.right = None