C++LeetCode543题解二叉树直径

class Solution {
private:
    int ans;
    int getDeepth(Treenode* root) {
        if (!root)
            return 0;
        int left = getDeepth(root->left);
        int right = getDeepth(root->right);
        ans = max(ans, left + right);
        return max(left, right) + 1;
    }
public:
    int diameterOfBinaryTree(TreeNode* root) {
        ans = 0;
        getDeepth(root);
        return ans;
    }
};