二叉树打印多行

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。

队列存储，每行设置行节点数，按照节点数输出。

代码

[code]/*
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>> res;
queue<TreeNode *> q;
vector<int> tmp;
if(!pRoot)
return res;
q.push(pRoot);
while(!q.empty()){
int cur_left=0,cur_right=q.size();
while(cur_left<cur_right){
cur_left++;
TreeNode *t=q.front();
q.pop();
tmp.push_back(t->val);
if(t->left)
q.push(t->left);
if(t->right)
q.push(t->right);
}
res.push_back(tmp);
tmp.clear();
}
return res;
}
};