题解 | #判断是不是完全二叉树#

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 *	TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 * };
 */
#include <asm-generic/errno.h>
class Solution {
public:
    /**
     * 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
     */
    bool isCompleteTree(TreeNode* root) 
    {
        if(root == nullptr)
        {
            return true;
        }

        queue<TreeNode*> q;
        q.push(root);

        int flog = 0;

        while(!q.empty())
        {
            int sz = q.size();
            for (int i = 0; i < sz; i++) 
            {
                TreeNode* cur = q.front();
                q.pop();

                if(cur == nullptr)
                {
                    flog = 1;
                }
                else 
                {
                    if(flog == 1)
                    {
                        return false;
                    }

                    q.push(cur->left);
                    q.push(cur->right);
                }
            }
        }
        return true;
    }
};