leetcode 222. 完全二叉树的节点个数

c++

class Solution {
public:
    int countNodes(TreeNode* root) {
        if (!root) return 0;
        return countNodes(root->left) + countNodes(root->right) + 1;
    }
};

js

var countNodes = function(root) {
    if (!root) return 0;
    return countNodes(root.left) + countNodes(root.right) + 1;
};