Binary Tree Zigzag Level Order Traversal @LeetCode

PROBLEM :

Given a binary tree, return the zigzag level order traversal of its nodes' values. (ie, from left to right, then right to left for the next level and alternate between).

For example:
Given binary tree [3,9,20,null,null,15,7],
    3
   / \
  9  20
    /  \
   15   7
 
return its zigzag level order traversal as:
[
  [3],
  [20,9],
  [15,7]
]

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SIMPLE c++ IMPLEMENTATION :
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/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */

class Solution {
public:
    vector<vector<int>> zigzagLevelOrder(TreeNode* root) {
        int height=FindHeight(root) ;
     
        vector<vector<int>> vec(height,vector<int> {});
        LevelTraversal(root,vec,0) ;
     
        for(int i=1;i<height;i+=2){
            vector<int> *v=&vec[i] ;
            reverse(v->begin(),v->end()) ;
        }
        return vec ;
    }
    int FindHeight(TreeNode* root){
        if(root==NULL)
            return 0 ;
         
        int l=FindHeight(root->left) ;
        int r=FindHeight(root->right) ;
        return l>r?l+1:r+1 ;
    }
 
    void LevelTraversal(TreeNode* root,vector<vector<int>> &vec,int curr){
        if(root==NULL)
            return ;
         
        vec[curr].push_back(root->val);
     
        LevelTraversal(root->left,vec,curr+1) ;
        LevelTraversal(root->right,vec,curr+1) ;
    }
};

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SIMPLE c++ IMPLEMENTATION : ( Better Solution )
--------------------------------------------------------------------------------

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */

class Solution {
public:
    vector<vector<int>> zigzagLevelOrder(TreeNode* root) {
        vector<vector<int>> vec ;
        if(root==NULL)
            return vec ;
         
        queue<TreeNode*> que ;
        que.push(root) ;
        bool status=true ;
     
        while(!que.empty()){
            int no=que.size() ;
            vector<int> row(no) ;
         
            for(int i=0;i<no;i++){
                TreeNode* curr=que.front() ;
                que.pop() ;
             
                int index=status?i:(no-i-1) ;
                row[index]=curr->val ;
             
                if(curr->left)
                    que.push(curr->left) ;
                if(curr->right)
                    que.push(curr->right) ;
            }
            status=!status ;
            vec.push_back(row) ;
        }
     
        return vec ;
    }
};

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