面试题60：把二叉树打印成多行

     题目：从上到下按层打印二叉树，同一层结点从左至右输出。每一层输出一行。

   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<int> vect;
vector<vector<int> > v;
if(pRoot == NULL)
return v;
queue<TreeNode *> queueNode;
queueNode.push(pRoot);
TreeNode *temp = NULL;
int nextNum = 0;
int toBePrint = 1;
while(!queueNode.empty())
{
temp = queueNode.front();
if(temp->left)
{
queueNode.push(temp->left);
nextNum++;
}
if(temp->right)
{
queueNode.push(temp->right);
nextNum++;
}
vect.push_back(temp->val);
queueNode.pop();
toBePrint--;
if(toBePrint == 0)
{
v.push_back(vect);
vect.resize(0);
toBePrint = nextNum;
nextNum = 0;
}
}
return v;
}

};