【刷题日记】二叉树-二叉树的层平均值-L637-Easy

class Solution {
public:
    vector<double> averageOfLevels(TreeNode* root) {
        vector<double> res;
        if (!root)
            return res;
        queue<TreeNode*> qe;
        qe.push(root);
        while (!qe.empty())
        {
            int node_num = qe.size();
            double sum_of_level = 0;
            for (int i = 0; i < node_num; i++)
            {
                auto tmp = qe.front();
                qe.pop();

                sum_of_level += tmp->val;

                if (tmp->left)
                    qe.push(tmp->left);
                if (tmp->right)
                    qe.push(tmp->right);
            }
            res.push_back(sum_of_level / node_num * 1.0);
        }

        return res;
    }
};