剑指offer_二叉树---把二叉树打印成多行

/**
 * 
 */
package offerTest;
import java.util.ArrayList;
import java.util.LinkedList;
/**
 * <p>
 * Title:Deep
 * </p>
 * <p>
 * Description:
 * </p>
 * 
 * @author 田茂林
 * @data 2017年8月21日 上午9:35:29
 */
public class Print {
    ArrayList<ArrayList<Integer>> ListPrint(TreeNode pRoot) {
        ArrayList<ArrayList<Integer>> listall = new ArrayList<ArrayList<Integer>>();
        LinkedList<TreeNode> queue = new LinkedList<TreeNode>();
        ArrayList<Integer> list = new ArrayList<Integer>();
        if (pRoot == null) {
            return listall;
        }
        int start = 0;
        int end = 1;
        int size = 0;
        queue.offer(pRoot);
        while (!queue.isEmpty()) {
            start++;
            TreeNode current = queue.poll();
            list.add(current.val);
            if (current.left != null) {
                queue.offer(current.left);
                size++;
            }
            if (current.right != null) {
                queue.offer(current.right);
                size++;
            }
            if (start == end) {
                start = 0;
                end = size;
                size = 0;
                listall.add(list);
                list = new ArrayList<Integer>();
            }
        }
        return listall;
    }
}