一、二叉树最大高度

class Solution {
public:
    int maxDepth(TreeNode* root) {
        if(root==nullptr)
        return 0;
     int left= maxDepth(root->left)+1;
     int right=maxDepth(root->right)+1;
      return left>right?left:right;
    }
};

二、n叉树最大高度

class Solution {
public:
    int maxDepth(Node* root) {
        if (root == nullptr) {
            return 0;
        }
        int maxChildDepth = 0;
        vector<Node *> children = root->children;
        for (auto child : children) {
            int childDepth = maxDepth(child);
            maxChildDepth = max(maxChildDepth, childDepth);
        }
        return maxChildDepth + 1;
    }
};