text: class Solution {
  public:
      int XXX(TreeNode* root) {
          if(root == NULL) return 0;
          return max(XXX(root -> left) + 1, XXX(root -> right) + 1);
      }
  };
  
  undefined
  for (i = 0; i < document.getElementsByTagName("code").length; i++) {     console.log(document.getElementsByTagName("code")[i].innerText); }
  
  
  