/* struct TreeNode { int val; struct TreeNode *left; struct TreeNode *right; TreeNode(int x) : val(x), left(NULL), right(NULL) { } }; */ class Solution {//层序遍历 public: vector<vector<int> > Print(TreeNode* pRoot) { vector<vector<int>> res; if(!pRoot) return res; queue<TreeNode*> p; p.push(pRoot); while(!p.empty()){ int i=0,n=p.size(); vector<int> val; while(i++<n){ TreeNode* q=p.front(); p.pop(); val.push_back(q->val); if(q->left) p.push(q->left); if(q->right) p.push(q->right); } res.push_back(val); } return res; } };