102.二叉树的层次遍历

😂

class Solution {
public:
    vector<vector<int>> levelOrder(TreeNode* root) {
        vector<vector<int>> vec;
        queue<TreeNode*> q;
        if(root)
            q.push(root);
        while(q.size()) {
            int sz = q.size();
            vec.push_back({});
            for(int i = 0; i < sz; ++i) {
                auto top = q.front();
                q.pop();
                auto& vec1 = vec.back();
                vec1.push_back(top->val);
                if(top->left)
                    q.push(top->left);
                if(top->right)
                    q.push(top->right);
            }
        }
        return vec;
    }
};

Accepted

34/34 cases passed (4 ms)

Your runtime beats 92.4 % of cpp submissions

Your memory usage beats 24.1 % of cpp submissions (14.2 MB)