leetcode

5 Database Problems

6 files changed, 64 insertions(+), 0 deletions(-)

diff --git a/ Problems/0177.sql b/ Problems/0177.sql

@@ -0,0 +1,12 @@

CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT

BEGIN

DECLARE M INT;

SET M = N - 1;

RETURN (

SELECT DISTINCT salary

FROM Employee

ORDER BY salary DESC

LIMIT 1

OFFSET M

);

END

diff --git a/ Problems/0184.sql b/ Problems/0184.sql

@@ -0,0 +1,11 @@

SELECT D.name AS Department,

E.name AS Employee,

E.salary

FROM Employee E

LEFT JOIN Department D

ON E.departmentId = D.id

WHERE (D.id, E.salary) IN (

SELECT departmentId, MAX(salary) AS salary

FROM Employee

GROUP BY departmentId

)

diff --git a/ Problems/0262.sql b/ Problems/0262.sql

@@ -0,0 +1,16 @@

SELECT request_at AS Day,

ROUND(AVG(status LIKE 'cancelled%'), 2) AS "Cancellation Rate"

FROM Trips

WHERE client_id IN (

SELECT users_id

FROM Users

WHERE banned = 'No'

)

AND driver_id IN (

SELECT users_id

FROM Users

WHERE banned = 'No'

)

AND request_at BETWEEN "2013-10-01" AND "2013-10-03"

GROUP BY request_at

diff --git a/ Problems/0601.sql b/ Problems/0601.sql

@@ -0,0 +1,8 @@

SELECT DISTINCT S1.*

FROM Stadium AS S1, Stadium AS S2, Stadium AS S3

WHERE S1.people >= 100 AND S2.people >= 100 AND S3.people >= 100

AND ((S1.id + 1 = S2.id AND S1.id + 2 = S3.id)

OR (S1.id - 1 = S2.id AND S1.id - 2 = S3.id)

OR (S1.id - 1 = S2.id AND S1.id + 1 = S3.id))

ORDER BY visit_date

diff --git a/ Problems/1158.sql b/ Problems/1158.sql

@@ -0,0 +1,12 @@

SELECT U.user_id AS buyer_id,

U.join_date,

COUNT(O.buyer_id) AS orders_in_2019

FROM Users U

LEFT JOIN (

SELECT buyer_id

FROM Orders

WHERE YEAR(order_date) = 2019

) AS O

ON U.user_id = O.buyer_id

GROUP BY U.user_id

diff --git a/ README.md b/ README.md

@@ -177,11 +177,13 @@ for solving problems. | 0173 | Medium | [Binary Search Tree Iterator](Problems/0173.cpp) | | 0175 | Easy | [Combine Two Tables](Problems/0175.cpp) | | 0176 | Medium | [Second Highest Salary](Problems/0176.cpp) |

| 0177 | Medium | [Nth Highest Salary](Problems/0177.cpp) |

| 0178 | Medium | [Rank Scores](Problems/0178.cpp) | | 0179 | Medium | [Largest Number](Problems/0179.cpp) | | 0180 | Medium | [Consecutive Numbers](Problems/0180.cpp) | | 0181 | Easy | [Employees Earning More Than Their Managers](Problems/0181.cpp) | | 0182 | Easy | [Duplicate Emails](Problems/0182.cpp) |

| 0184 | Medium | [Department Highest Salary](Problems/0184.cpp) |

| 0185 | Hard | [Department Top Three Salaries](Problems/0185.cpp) | | 0187 | Medium | [Repeated DNA Sequences](Problems/0187.cpp) | | 0189 | Medium | [Rotate Array](Problems/0189.cpp) |

@@ -234,6 +236,7 @@ for solving problems. | 0257 | Easy | [Binary Tree Paths](Problems/0257.cpp) | | 0258 | Easy | [Add Digits](Problems/0258.cpp) | | 0260 | Medium | [Single Number III](Problems/0260.cpp) |

| 0262 | Hard | [Trips and Users](Problems/0262.cpp) |

| 0263 | Easy | [Ugly Number](Problems/0263.cpp) | | 0264 | Medium | [Ugly Number II](Problems/0264.cpp) | | 0268 | Easy | [Missing Number](Problems/0268.cpp) |

@@ -369,6 +372,7 @@ for solving problems. | 0590 | Easy | [N-ary Tree Postorder Traversal](Problems/0590.cpp) | | 0595 | Easy | [Big Countries](Problems/0595.cpp) | | 0596 | Easy | [Classes More Than 5 Students](Problems/0596.cpp) |

| 0601 | Hard | [Human Traffic of Stadium](Problems/0601.cpp) |

| 0602 | Medium | [Friend Requests II: Who Has the Most Friends](Problems/0602.cpp) | | 0605 | Easy | [Can Place Flowers](Problems/0605.cpp) | | 0606 | Easy | [Construct String from Binary Tree](Problems/0606.cpp) |

@@ -579,6 +583,7 @@ for solving problems. | 1143 | Medium | [Longest Common Subsequence](Problems/1143.cpp) | | 1146 | Medium | [Snapshot Array](Problems/1146.cpp) | | 1148 | Easy | [Article Views I](Problems/1148.cpp) |

| 1158 | Medium | [Market Analysis I](Problems/1158.cpp) |

| 1160 | Easy | [Find Words That Can Be Formed by Characters](Problems/1160.cpp) | | 1161 | Medium | [Maximum Level Sum of a Binary Tree](Problems/1161.cpp) | | 1162 | Medium | [As Far from Land as Possible](Problems/1162.cpp) |