二叉树按行打印

原来真的有，，，，把刚刚之字形打印的代码改一个地方就可以了，就是不用翻转了

public class Solution {


public ArrayList<ArrayList<Integer> > Print(TreeNode pRoot) {
    ArrayList<ArrayList<Integer>> res=new ArrayList<>();
    LinkedList<TreeNode> list1=new  LinkedList<>();
    LinkedList<TreeNode> list2=new  LinkedList<>();
    if(pRoot==null){
        return res;
    }
    list1.add(pRoot);
    while(!list1.isEmpty() || !list2.isEmpty()){ 
        if(!list1.isEmpty()){ 
            printTreeNode(res,list1,0);
        }
        while(!list1.isEmpty()){ 
            addList(list1,list2);
        }
        if(!list2.isEmpty()){ 
            printTreeNode(res,list2,0); //修改一下这里，1 改为了0
        }
        while(!list2.isEmpty()){ 
            addList(list2,list1);
        }
    }
    return res;
}

public void printTreeNode(ArrayList<ArrayList<Integer>> res,LinkedList<TreeNode> list,int mode){ 
    ArrayList<Integer> listNums=new ArrayList<>();
    if(mode==0){
        for(TreeNode root:list){
            listNums.add(root.val);
        }
    }else{
        for(int i=list.size()-1;i>=0;i--){
            listNums.add(list.get(i).val);
        }
    }
    res.add(listNums);
    return ;
}


public void addList(LinkedList<TreeNode> list1,LinkedList<TreeNode> list2){
    TreeNode root=list1.removeFirst();
    if(root.left!=null){
        list2.add(root.left);
    }
    if(root.right!=null){
        list2.add(root.right);
    }
}

}