Leetcode-Binary Tree Level Order Traversal

Given a binary tree, return the level order traversal of its nodes’ values. (ie, from left to right, level by level).

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

/**
 * 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>> result;
        if(root==NULL)
        return result;

        TreeNode *p=root;
        queue<TreeNode*> que1,que2;
        que1.push(p);
        while(que1.size()!=0 || que2.size()!=0){
            vector<int> odd,even;
            while(que1.size()){
                TreeNode *tmp=que1.front();
                que1.pop();
                odd.push_back(tmp->val);                
                if(tmp->left) que2.push(tmp->left);
                if(tmp->right) que2.push(tmp->right);     
            }
            if(odd.size()) result.push_back(odd);
            while(que2.size()){
                TreeNode *tmp=que2.front();
                que2.pop();
                even.push_back(tmp->val);
                if(tmp->left) que1.push(tmp->left);
                if(tmp->right) que1.push(tmp->right);
            }
            if(even.size()){
                reverse(even.begin(),even.end());
                result.push_back(even);
            }
        }
        return result;
    }
};



//測試代碼
struct TreeNode {
      int val;
      TreeNode *left;
      TreeNode *right;
      TreeNode(int x) : val(x), left(NULL), right(NULL) {}
  };

    TreeNode* initBTree(vector<int> input)  
{  
    int size=input.size();
   // cout<<"input.size:"<<size<<endl;
    if (size < 1)  
    {  
        return NULL;  
    }  
    //動態申請size大小的指針數組  
    TreeNode **nodes = new TreeNode*[size];  
    //將int數據轉換爲TreeNode節點  
    for (int i = 0; i < size; i++)  
    {  
        if (input[i] == 0)  
        {  
            nodes[i] = NULL;  
        }  
        else  
        {  
            nodes[i] = new TreeNode(input[i]);  
        }  
    }  
    queue<TreeNode*> nodeQueue;  
    nodeQueue.push(nodes[0]);  

    TreeNode *node;  
    int index =1;  

    while (index < size )  
    {        
        node = nodeQueue.front();              
        nodeQueue.pop();
        //handle left son
        if(nodes[index]){
            nodeQueue.push(nodes[index]);
            node->left=nodes[index];
        }
        index++;
        //handle right son
        if(index<size && nodes[index]){           
            nodeQueue.push(nodes[index]);
            node->right=nodes[index];
        }
         index++;           
    } 
    return nodes[0];  
} 

int main()
{
    vector<int> input={};//3,9,20,0,0,15,7
    vector<int> inResult;  
    TreeNode *root=initBTree(input);
  //  inOrder(root);
     vector<vector<int>> result=zigzagLevelOrder(root);
    for(int i=0;i<result.size();i++){
        for(int j=0;j<result[i].size();j++){
            cout<<result[i][j]<<" ";
        }
        cout<<endl;
    }
    return 0;
}