层次遍历
import java.util.*;
/*
* public class TreeNode {
* int val = 0;
* TreeNode left = null;
* TreeNode right = null;
* public TreeNode(int val) {
* this.val = val;
* }
* }
*/
public class Solution {
/**
* 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
*
*
* @param root TreeNode类
* @return bool布尔型
*/
public boolean isCompleteTree (TreeNode root) {
// write code here
if(root == null){
return true;
}
Queue<TreeNode> queue = new LinkedList<>();
queue.offer(root);
boolean complete = false;
TreeNode cur;
while(!queue.isEmpty()){
cur = queue.poll();
if(cur == null){
complete = true;
continue;
}
if(complete){
return false;
}
queue.offer(cur.left);
queue.offer(cur.right);
}
return true;
}
}