跟上一题,102的思路一样,不过输出前判断当前是奇数深度还是偶数深度,奇数深度正着输出,偶数深度倒着输出;
class Solution {
public:
vector<vector<int>> zigzagLevelOrder(TreeNode* root) {
queue<TreeNode*>que;
vector<vector<int>>result;
if(root==nullptr)
return result;
que.push(root);
int k=1;
while(!que.empty())
{
vector<int>vec;
vector<TreeNode*>vec_que;
while(!que.empty())
{
root=que.front();
vec.push_back(root->val);
vec_que.push_back(root);
que.pop();
}
if(k%2==0)
{
vector<int>rvec;
for(int i=vec.size()-1;i>=0;i--)
{
rvec.push_back(vec[i]);
}
result.push_back(rvec);
}
else result.push_back(vec);
k++;
for(int i=0;i<vec_que.size();i++)
{
if(vec_que[i]->left)
que.push(vec_que[i]->left);
if(vec_que[i]->right)
que.push(vec_que[i]->right);
}
}
return result;
}
};