我的解题:
因为先做的双向队列的那道题,所以这道题比较简单写,直接queue层次遍历即可
class Solution {
public:
vector<vector<int>> levelOrder(TreeNode* root) {
vector<vector<int>> res;
if(!root) return res;
vector<int> line;
TreeNode* tmp;
queue<TreeNode*> q;
q.push(root);
while(!q.empty()){
int n=q.size();
while(n--){
tmp=q.front();
q.pop();
line.push_back(tmp->val);
if(tmp->left) q.push(tmp->left);
if(tmp->right) q.push(tmp->right);
}
res.push_back(line);
line.clear();
}
return res;
}
};