Made a stupid bug....... When reverse the vector, stop it at mid. Otherwise, it will swap back......

Mark!!!!!!!!

1 /** 2  * Definition for binary tree 3  * struct TreeNode { 4  *     int val; 5  *     TreeNode *left; 6  *     TreeNode *right; 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} 8  * }; 9  */10 class Solution {11 public:12     vector
     
      
        > zigzagLevelOrder(TreeNode *root) {13         vector
       
        
          > result;14         vector
         
           level;15         if (!root) return result;16         int current = 1, future = 0;17         bool flag = false;18         queue
          
            q;19 q.push(root);20 auto func = [](int &a, int &b) { int t = a; a = b; b = t;};21 while (!q.empty()) {22 TreeNode *tmp = q.front();23 q.pop(), current--;24 if (tmp->left) {25 q.push(tmp->left);26 future++;27 }28 if (tmp->right) {29 q.push(tmp->right);30 future++;31 }32 level.push_back(tmp->val);33 if (!current) {34 if (flag) {35 for (int i = 0; i < level.size()/2; i++) {36 func(level[i], level[level.size()-i-1]);37 }38 }39 flag ^= 1;40 result.push_back(level);41 level.clear();42 current = future;43 future = 0;44 }45 }46 return result;47 }48 };