import java.util.*;
public class Main {
/**
//该段代码仅用于调试,提交时请注释该段代码
class TreeNode<T> {
public T data;
public TreeNode<T> left;
public TreeNode<T> right;
}
*/
public int solution(TreeNode<Integer> root) {
if(root ==null){
return 0;
}
Queue<TreeNode<Integer>> q = new LinkedList<>();
TreeNode<Integer>p=root;
q.add(p);
int len = 0;
while (q.isEmpty() == false)
{
len++;
int sz = q.size();
while (sz!=0)
{
p=q.poll();
//printf("%c ",p->val);
if (p.left != null)
{
q.add(p.left);
}
if (p.right != null)
{
q.add(p.right);
}
sz--;
}
}
return len;
}
}