chelseajcole-优快云博客

原创 Leetcode 133. Clone Graph

Leetcode 133. Clone GraphGiven a reference of a node in a connected undirected graph.Return a deep copy (clone) of the graph.Each node in the graph contains a value (int) and a list (List[Node]) of its neighbors.class Node { public int val; pub

2021-07-30 00:03:36 314

原创 Leetcode1482. Minimum Number of Days to Make m Bouquets [Medium] Python Binary Search

Given an integer arraybloomDay, an integermand an integerk.We need to makembouquets. To make a bouquet,you need to usekadjacent flowersfrom the garden.The garden consists ofnflowers, theithflower will bloom in thebloomDay[i]and then can...

2020-08-13 01:13:45 279

原创 Leetcode 410 Split Array Largest Sum [Hard] Python Binary Search

Given an array which consists of non-negative integers and an integerm, you can split the array intomnon-empty continuous subarrays. Write an algorithm to minimize the largest sum among thesemsubarrays.Note:Ifnis the length of array, assume the f...

2020-08-12 23:52:08 526

原创 Leetcode 1148.1149 Article Views

drop table ViewsCreate table Views (article_id int, author_id int, viewer_id int, view_date date)insert into Views (article_id, author_id, viewer_id, view_date) values ('1', '3', '5', '2019-08-01'...

2020-03-10 06:14:35 704

原创 Leetcode 1113. 1132 Reported Posts

drop table ActionsCreate table Actions (user_id int, post_id int, action_date date, action varchar(20), extra varchar(20))insert into Actions (user_id, post_id, action_date, action, extra) values ...

2020-03-09 06:30:16 764

原创 Leetcode 1141. 1142 User Activity for the Past 30 Days

drop table ActivityCreate table Activity (user_id int, session_id int, activity_date date, activity_type varchar(20))insert into Activity (user_id, session_id, activity_date, activity_type) values...

2020-03-09 04:11:11 2438

原创 LeetCode 1158,1159 Market Analysis

drop table Usersdrop table Ordersdrop table Itemscreate table Users (user_id int, join_date date, favorite_brand varchar(20))create table Orders (order_id int, order_date date, item_id int, buyer...

2020-03-08 09:16:18 783

原创 LeetCode 1075, 1076,1077 Project Employees

drop table Projectdrop table EmployeeCreate table Project (project_id int, employee_id int)Create table Employee (employee_id int, name varchar(20), experience_years int)insert into Project (pro...

2020-03-08 05:27:34 392

原创 LeetCode 1082,1083,1084 Sales Analysis

Create table If Not Exists Product (product_id int, product_name varchar(10), unit_price int)Create table If Not Exists Sales (seller_id int, product_id int, buyer_id int, sale_date date, quantity i...

2020-03-07 00:53:46 324

原创 Email Open Rate

Create table emails (email_id int, sent_date DATE NULL, status varchar(20))Truncate table emailsinsert into emails (email_id, sent_date, status) values ('1', '2017-01-01', 'sent')insert into email...

2019-09-18 05:19:42 460

原创 Leetcode 601. Human Traffic of Stadium

X city built a new stadium, each day many people visit it and the stats are saved as these columns:id,visit_date,peoplePlease write a query to display the records which have 3 or more consecutive...

2019-09-18 04:36:39 542

原创 LeetCode 615 Average Salary: Departments VS Company

Given two tables as below, write a query to display the comparison result (higher/lower/same) of the average salary of employees in a department to the company's average salary.So for the sample ...

2019-09-17 04:38:17 313

原创 LeetCode 1068 1069 Product Sales Analysis

drop table Productdrop table SalesCreate table Sales(sale_id int,product_id int,year int,quantity int,price int);Create table Product(product_id int,product_name varchar(20));insert into Sales v...

2019-09-10 11:59:39 339

原创 LeetCode 511, 512, 534, 550 Game Play Analysis

(player_id, event_date) is the primary key of this table.This table shows the activity of players of some game.Each row is a record of a player who logged in and played a number of games (possibly 0...

2019-09-09 11:08:35 1315

原创 LeetCode 1075. 1076 Project Employees

drop table Projectdrop table EmployeesCreate table Project(project_id int,employee_id int);insert into Project values(1,1);insert into Project values(1,2);insert into Project values(1,3);inse...

2019-09-08 12:23:15 480

原创 Leetcode 594. Longest Harmonious Subsequence Python

594.Longest Harmonious SubsequenceWe define a harmounious array as an array where the difference between its maximum value and its minimum value isexactly1.Now, given an integer array, you need...

2019-08-01 11:54:10 231

原创 Leetcode Backtracking Python

Backtracking 的基本套路是for循环加一个dfs.77.CombinationsGiven two integersnandk, return all possible combinations ofknumbers out of 1 ...n.Input:n = 4, k = 2Output:[ [2,4], [3,4], [2...

2019-07-28 11:01:51 148

原创 Leetcode 126. Word Ladder II Python BFS 实现

题目：126.Word Ladder IIhttps://leetcode.com/problems/word-ladder-ii/Given two words (beginWordandendWord), and a dictionary's word list, find all shortest transformation sequence(s) frombeginWor...

2019-06-29 03:34:18 1590

原创 659. Split Array into Consecutive Subsequences Python 贪心算法

题目：659.Split Array into Consecutive Subsequenceshttps://leetcode.com/problems/split-array-into-consecutive-subsequences/You are given an integer array sorted in ascending order (may contain dupli...

2019-06-27 04:23:45 231

原创 Leetcode 15. 3Sum 18. 4Sum 通用解法for N Sum Python

15.3SumGiven an arraynumsofnintegers, are there elementsa,b,cinnumssuch thata+b+c= 0? Find all unique triplets in the array which gives the sum of zero.Note:The solution set mus...

2019-05-13 10:01:19 217

原创 Leetcode 262. Trips and Users SQL Server

TheTripstable holds all taxi trips. Each trip has a unique Id, while Client_Id and Driver_Id are both foreign keys to the Users_Id at theUserstable. Status is an ENUM type of (‘completed’, ‘cancel...

2019-05-10 10:53:18 182

原创 Leetcode 717. 1-bit and 2-bit Characters Python

We have two special characters. The first character can be represented by one bit0. The second character can be represented by two bits (10or11).Now given a string represented by several bits. Re...

2019-04-14 11:18:46 101

原创 Leetcode 697. Degree of an Array 最大频率数字的最短子数组 Python实现

题目：Given a non-empty array of non-negative integersnums, thedegreeof this array is defined as the maximum frequency of any one of its elements.Your task is to find the smallest possible length ...

2019-04-14 11:01:15 730

原创 Leetcode 665 Non-decreasing Array 非递减数列 Python 实现

题目：Given an array withnintegers, your task is to check if it could become non-decreasing by modifyingat most1element.We define an array is non-decreasing ifarray[i] <= array[i + 1]holds ...

2019-04-13 11:47:04 281

转载 Leetcode 603. Consecutive Available Seats

Several friends at a cinema ticket office would like to reserve consecutive available seats.Can you help to query all the consecutive available seats order by the seat_id using the following cinemata...

2018-08-25 00:04:53 1311 1

转载 Leetcode 577. Employee Bonus

2018-08-24 23:55:03 664

转载 Leetcode 607. Sales Person

DescriptionGiven three tables: salesperson, company, orders.Output all the names in the table salesperson, who didn’t have sales to company 'RED'.ExampleInputTable: salesperson+----------+--...

2018-08-24 23:46:46 1382

转载 LeetCode 597. Friend Requests I: Overall Acceptance Rate

In social network like Facebook or Twitter, people send friend requests and accept others’ requests as well. Now given two tables as below: Table: friend_request| sender_id | send_to_id |reques...

2018-08-23 11:01:51 999

转载 LeetCode 619. Biggest Single Number

Table number contains many numbers in column num including duplicated ones.Can you write a SQL query to find the biggest number, which only appears once.+---+|num|+---+| 8 || 8 || 3 || 3 ||...

2018-08-22 10:26:58 540

转载 LeetCode 570. Managers with at Least 5 Direct Reports

The Employee table holds all employees including their managers. Every employee has an Id, and there is also a column for the manager Id.+------+----------+-----------+----------+|Id |Name |...

2018-08-22 10:22:41 815

转载 LeetCode 608. Tree Node

Given a table tree, id is identifier of the tree node and p_id is its parent node's id.+----+------+| id | p_id |+----+------+| 1 | null || 2 | 1 || 3 | 1 || 4 | 2 || 5 | 2 ...

2018-08-22 09:54:02 1343

转载 Leetcode 612. Shortest Distance in a Plane

Table point_2d holds the coordinates (x,y) of some unique points (more than two) in a plane. Write a query to find the shortest distance between these points rounded to 2 decimals. | x | y ...

2018-08-21 10:56:24 895

转载 Leetcode 585. Investments in 2016

Write a query to print the sum of all total investment values in 2016 (TIV_2016), to a scale of 2 decimal places, for all policy holders who meet the following criteria:Have the same TIV_2015 value ...

2018-08-21 10:41:20 1122

转载 Leetcode 602. Friend Requests II: Who Has Most Friend?

In social network like Facebook or Twitter, people send friend requests and accept others' requests as well. Table request_accepted holds the data of friend acceptance, while requester_id and acce...

2018-08-19 00:25:11 907

转载 Leetcode 580. Count Student Number in Departments

A university uses 2 data tables, student and department, to store data about its students and the departments associated with each major.Write a query to print the respective department name and num...

2018-08-19 00:17:44 822

转载 LeetCode 574. Winning Candidate SQL Server

create table candidate(id int,Name varchar(2))insert into candidate values (1,'A')insert into candidate values (2,'B')insert into candidate values (3,'C')insert into candidate values (4,'D')ins...

2018-08-17 10:31:59 831

原创 LeetCode 578. Get Highest Answer Rate Question

Get the highest answer rate question from a tablesurvey_logwith these columns:uid,action,question_id,answer_id,q_num,timestamp.uid means user id; action has these kind of values: "show", "an...

2018-08-16 11:13:55 832

转载 571 Find Median Given Frequency of Numbers SQL Server with CTE

drop table numberscreate Table numbers (number int,frequency int)insert into numbers values (0,7)insert into numbers values (1,1)insert into numbers values (2,3)insert into numbers values (3,1...

2018-08-15 11:04:44 1210

翻译 LeetCode 618. Students Report By Geography

drop table studentcreate Table student (name varchar(25),continent varchar(25));insert into student values('Jack','America')insert into student values('Pascal','Europe')insert into student value...

2018-08-14 09:30:45 1736

翻译 LeetCode 615. Average Salary: Departments VS Company

drop table salaryCreate table salary(Id int,employee_id int,amount int,pay_date date);insert into salary values(1,1,9000,'2017-03-31');insert into salary values(2,2,6000,'2017-03-31');insert int...

2018-08-13 11:47:17 1090