题解 | #把二叉树打印成多行#
把二叉树打印成多行
http://www.nowcoder.com/practice/445c44d982d04483b04a54f298796288
public class Solution {
ArrayList<ArrayList<Integer> > Print(TreeNode pRoot) {
Queue<TreeNode> q=new LinkedList<TreeNode>();
ArrayList<Integer> arr=new ArrayList<Integer>();
ArrayList<ArrayList<Integer> > arr1=new ArrayList<ArrayList<Integer> >();
if(pRoot==null) return arr1;
TreeNode cur=pRoot,last=pRoot;TreeNode tail=pRoot;
q.offer(cur);
while(!q.isEmpty())
{
cur=q.poll();
arr.add(cur.val);
if(cur.left!=null)
{
q.offer(cur.left);
tail=cur.left;
}
if(cur.right!=null)
{
q.offer(cur.right);
tail=cur.right;
}
if(last==cur)
{
last=tail;
arr1.add(new ArrayList(arr));
arr.clear();
}
}
return arr1;
}
} 