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,#,#,15,7} ,

    3   /   9    /   7

Return its level order traversal as:

[  3],  [9,20],  [15,7]]

/** Definition for binary tree * struct TreeNode {* int val; * TreeNode *left; * TreeNode *right; * TreeNode (int x): Val (x), left (null), right (NULL) {} *}; */classSolution { Public: Vector<vector<int> > Levelorder (TreeNode *root) {Vector<vector<int> >VEC; if(Root = NULL)returnVEC; Queue<treenode *>CRT, wait;        Crt.push (root);  while(Crt.size () >0){            intnum =crt.size (); Vector<int>arr;  while(num--) {TreeNode*tmp =Crt.front (); if(tmp->left) Wait.push (tmp->Left ); if(tmp->right) Wait.push (tmp->Right ); Arr.push_back (TMP-val);            Crt.pop ();            } vec.push_back (arr); intn =wait.size ();  while(n--) {TreeNode*tmp =Wait.front ();                Wait.pop ();            Crt.push (TMP); }        }        returnVEC; }};

Binary Tree level Order traversal