[leetcode] Binary Tree Zigzag Level Order Traversal

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,#,#,15,7},

    3
   / \
  9  20
    /  \
   15   7

return its zigzag level order traversal as:

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

confused what "{1,#,2,3}" means? > read more on how binary tree is serialized on OJ.

class Solution {
public:
    vector<vector<int> > zigzagLevelOrder(TreeNode *root) {
		// Start typing your C/C++ solution below
		// DO NOT write int main() function
		vector<vector<int> >ret;
		vector<int> inner;
		bool direction=false;
		TreeNode **array=new TreeNode*[10000];
		if(!root)
			return ret;
		array[0]=root;
		inner.push_back(root->val);
        ret.push_back(inner);
		int p=0,flag=1,q=1;
		for( ; p!=q ; p++ ){
			if(p==flag){
				flag=q;
                inner.clear();
				if(!direction){
					for(int i=q-1 ; i>=p ; i--)
						inner.push_back(array[i]->val);
				}
				else{
					for(int i=p ; i<q ; i++)
						inner.push_back(array[i]->val);
				}
				direction=!direction;
				ret.push_back(inner);
			}
			if(array[p]->left)
				array[q++]=array[p]->left;
			if(array[p]->right)
				array[q++]=array[p]->right;
		}
		return ret;
	}
};