题解 | JAVA #判断是不是完全二叉树# [P0-T2]

跟这题一样的 https://blog.nowcoder.net/n/4012546b98ae4356ab926184ed323c58

import java.util.*;

public class Solution {

    public boolean isCompleteTree (TreeNode root) {
      if (root == null) return false;
      Queue<TreeNode> q = new LinkedList<>();
      q.offer(root);
      boolean ended = false;
      
      while(!q.isEmpty()) {
        TreeNode pop = q.poll();
        if (pop == null) {
          ended = true;
        } else {
          if (ended) return false;
          q.offer(pop.left);
          q.offer(pop.right);
        }
      }
      return true;
    }
}