1.判断每层的最左最右节点
2.构建一个二维数组装左右节点
3.打印左边界
4.打印非边界的叶子节点
5.打印右边界
public class Code_02PrintEdgel {
public class Node{
public int value;
public Node left;
public Node right;
public Node(int data){
this.value = data;
}
}