#codingexercise
Make Array Zero by Subtracting Equal Amounts
You are given a non-negative integer array nums. In one operation, you must:
• Choose a positive integer x such that x is less than or equal to the smallest non-zero element in nums.
• Subtract x from every positive element in nums.
Return the minimum number of operations to make every element in nums equal to 0.
Example 1:
Input: nums = [1,5,0,3,5]
Output: 3
Explanation:
In the first operation, choose x = 1. Now, nums = [0,4,0,2,4].
In the second operation, choose x = 2. Now, nums = [0,2,0,0,2].
In the third operation, choose x = 2. Now, nums = [0,0,0,0,0].
Example 2:
Input: nums = [0]
Output: 0
Explanation: Each element in nums is already 0 so no operations are needed.
Constraints:
• 1 <= nums.length <= 100
• 0 <= nums[i] <= 100
import java.util.*;
import java.util.stream.*;
class Solution {
public int minimumOperations(int[] nums) {
List<Integer> list = Arrays.stream(nums).boxed().collect(Collectors.toList());
var nonZero = list.stream().filter(x -> x > 0).collect(Collectors.toList());
int count = 0;
while(nonZero.size() > 0) {
var min = nonZero.stream().mapToInt(x -> x).min().getAsInt();
nonZero = nonZero.stream().map(x -> x - min).filter(x -> x > 0).collect(Collectors.toList());
count++;
}
return count;
}
}
Input
nums =
[1,5,0,3,5]
Output
3
Expected
3
Input
nums =
[0]
Output
0
Expected
0
SQL Schema
Table: Books
+----------------+---------+
| Column
Name | Type |
+----------------+---------+
| book_id | int |
| name | varchar |
| available_from
| date |
+----------------+---------+
book_id is the
primary key of this table.
Table: Orders
+----------------+---------+
| Column
Name | Type |
+----------------+---------+
| order_id | int
|
| book_id | int
|
| quantity | int
|
|
dispatch_date | date |
+----------------+---------+
order_id is the
primary key of this table.
book_id is a
foreign key to the Books table.
Write an SQL
query that reports the books that have sold less than 10 copies in the last
year, excluding books that have been available for less than one month from
today. Assume today is 2019-06-23.
Return the
result table in any order.
The query
result format is in the following example.
Example 1:
Input:
Books table:
+---------+--------------------+----------------+
| book_id |
name | available_from |
+---------+--------------------+----------------+
| 1 | "Kalila And Demna" |
2010-01-01 |
| 2 | "28 Letters" | 2012-05-12 |
| 3 |
"The Hobbit" |
2019-06-10 |
| 4 | "13 Reasons Why" | 2019-06-01 |
| 5 | "The Hunger Games" |
2008-09-21 |
+---------+--------------------+----------------+
Orders table:
+----------+---------+----------+---------------+
| order_id |
book_id | quantity | dispatch_date |
+----------+---------+----------+---------------+
| 1 | 1 | 2 | 2018-07-26 |
| 2 | 1 | 1 | 2018-11-05 |
| 3 | 3 | 8 | 2019-06-11 |
| 4 | 4
| 6 | 2019-06-05 |
| 5 | 4 | 5 | 2019-06-20 |
| 6 | 5 | 9 | 2009-02-02 |
| 7 | 5 | 8 | 2010-04-13 |
+----------+---------+----------+---------------+
Output:
+-----------+--------------------+
| book_id | name |
+-----------+--------------------+
| 1 | "Kalila And Demna" |
| 2 | "28 Letters" |
| 5 | "The Hunger Games" |
+-----------+--------------------+
SELECT DISTINCT
b.book_id, b.name
FROM books b
LEFT JOIN
Orders o on b.book_id = o.book_id
GROUP BY
b.book_id, b.name,
DATEDIFF(day,
DATEADD(year, -1, '2019-06-23'), o.dispatch_date),
DATEDIFF(day, b.available_from, DATEADD(month, -1,
'2019-06-23'))
HAVING
SUM(o.quantity) IS NULL OR
DATEDIFF(day,
DATEADD(year, -1, '2019-06-23'), o.dispatch_date) < 0 OR
(DATEDIFF(day,
DATEADD(year, -1, '2019-06-23'), o.dispatch_date) > 0 AND DATEDIFF(day, b.available_from, DATEADD(month, -1,
'2019-06-23')) > 0 AND SUM(o.quantity) < 10);
Case 1
Input
Books =
| book_id |
name | available_from |
| ------- |
---------------- | -------------- |
| 1 | Kalila
And Demna | 2010-01-01 |
| 2 | 28
Letters | 2012-05-12 |
| 3 | The
Hobbit | 2019-06-10 |
| 4 | 13
Reasons Why | 2019-06-01 |
| 5 | The
Hunger Games | 2008-09-21 |
Orders =
| order_id |
book_id | quantity | dispatch_date |
| -------- |
------- | -------- | ------------- |
| 1 | 1 | 2 |
2018-07-26 |
| 2 | 1 | 1 |
2018-11-05 |
| 3 | 3 | 8 |
2019-06-11 |
| 4 | 4 | 6 |
2019-06-05 |
| 5 | 4 | 5 |
2019-06-20 |
| 6 | 5 | 9 |
2009-02-02 |
| 7 | 5 | 8 |
2010-04-13 |
Output
| book_id |
name |
| ------- |
---------------- |
| 2 | 28
Letters |
| 1 | Kalila
And Demna |
| 5 | The
Hunger Games |
Expected
| book_id |
name |
| ------- |
---------------- |
| 1 | Kalila
And Demna |
| 2 | 28
Letters |
| 5 | The Hunger Games |
