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https://leetcode-cn.com/problems/reorder-list/ Given a singly linked list L: L0→L1→…→Ln-1→Ln, reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→… You may not modify the values in the list's nodes, only nodes itself may be changed. 题意 给定一个单链表 L:L0→L1→…→Ln-1...
来源:力扣(LeetCode)链接:https://leetcode.cn/problems/all-the-pairs-with-the-maximum-number-of-common-followers #测试数据 Create table If Not Exists Relations (user_id int, follower_id int); insert into Relations (user_id, follower_id) values ('1', '3'); insert into Relations (user_...
Write a SQL query to find all customers who never order anything. Using the above tables as an example, return the following: 三、参考SQL 方法一:左外连接 1selectNameasCustomers2fromCustomers c3leftjoinOrders o4onc.Id=o.CustomerId5whereo.Idisnull; ...
链接:https://leetcode.cn/problems/all-the-pairs-with-the-maximum-number-of-common-followers #测试数据 Create table If Not ExistsRelations(user_id int,follower_id int);insert intoRelations(user_id,follower_id)values('1','3');insert intoRelations(user_id,follower_id)values('2','3');inser...
这道题的题意也很简单,只有一句话:“Given a collection of intervals, merge all overlapping intervals.” interval是间隔、区间的意思,也就是说题目会给我们一系列区间,让我们把这些区间合并在一起。 我们看下题目给的样例来感受一下: “Input: [
链接:https://leetcode-cn.com/problems/monthly-transactions-ii 著作权归领扣网络所有。商业转载请联系官方授权,非商业转载请注明出处。 题解 两张表加tag字段区分,查询出需要的子段,并用union all合两张表(PS:union all不去重复数据行,union去重复行) 作为新表 ...
Write a SQL query to find all numbers that appear at least three times consecutively. For example, given the above Logs table, 1 is the only number that appears consecutively for at least three times. 三、参考SQL 方法一:多次连接 select distinct a.num as ConsecutiveNumsfrom Logs ainner join...
union all select 'Programming' ) en left join experiments e on p.platform=e.platform and en.experiment_name = e.experiment_name group by p.platform, en.experiment_name; 82.低质量的问题 select problem_id from Problems where (likes / (likes + dislikes)) * 100 < 60 ...