CodingInterview-按之字形顺序打印二叉树

和上一道题思路差不多，只是这次插入数字的方向需要换一下。

/*
struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
    TreeNode(int x) :
            val(x), left(NULL), right(NULL) {
    }
};
*/
class Solution {
public:
    vector<vector<int> > Print(TreeNode* pRoot) {
        vector<vector<int>> result;
            if(pRoot==NULL) return result;
            queue<TreeNode*> q;
            q.push(pRoot);
            int now=1,next=0,layer=0;
            vector<int>* v=new vector<int>();
            while(!q.empty()){
                TreeNode* t=q.front();
                q.pop();
                now--;
                if(layer%2==0){
                    v->push_back(t->val);
                }else{
                    v->insert(v->begin(),t->val);
                }
                if(t->left!=NULL) {
                    q.push(t->left);
                    next++;
                }
                if(t->right!=NULL) {
                    q.push(t->right);
                    next++;
                }
                if(now==0){
                    now=next;
                    next=0;
                    layer++;
                    result.push_back(*v);
                    v=new vector<int>();
                }
            }
            return result;
    }

};