[leetCode]Binary Tree Zigzag Level Order Traversal

/**
* Definition for binary tree
* struct TreeNode {
*     int val;
*     TreeNode *left;
*     TreeNode *right;
*     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
#include <list>
#include <vector>
using namespace std;
struct TreeNode {
int val;
TreeNode *left;
TreeNode *right;
TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};
class Solution {
public:
list<vector<TreeNode>> levelNode;
vector<vector<int>> allLevelval;
vector<vector<int>> zigzagLevelOrder(TreeNode *root) {
vector<TreeNode> curVec;
vector<int> curIntList;
if(levelNode.empty() && root != NULL){
curVec.push_back(*root);
levelNode.push_back(curVec);
}
bool zigzag = true;
for(list<vector<TreeNode>>::iterator iter = levelNode.begin();iter != levelNode.end();iter++){
int size = iter->size();
curVec.clear();
curIntList.clear();
for(int i = 0 ; i< size; i++){
TreeNode curNode = iter->at(i);
if(curNode.left != NULL) curVec.push_back(*curNode.left);
if(curNode.right != NULL) curVec.push_back(*curNode.right);

if(zigzag){
curIntList.push_back(curNode.val);
}else{
curIntList.insert(curIntList.begin(),curNode.val);
}
}
allLevelval.push_back(curIntList);

if(curVec.empty()) break;
levelNode.push_back(curVec);
zigzag = !zigzag;
}
return allLevelval;
}
};