We Keep Coding

What regular expression need for match nested expression?

I'm triying to make a regex in .net to match nested expresion.
I wan't to extract a condition and value1 and value2 like this:
CASE WHEN condition THEN value1 ELSE value2 END
The string that i would like to match it's this:
CASE WHEN 5 + CASE WHEN 6 < 3 THEN 5 ELSE 2 END = 0 THEN 0 ELSE CASE WHEN 6 < 0 THEN 2 ELSE 1 END / (3 + CASE WHEN 5 < 0 THEN 2 ELSE 0 END) END
Formatted string:
CASE WHEN 5 +
CASE WHEN 6 < 3
THEN 5
ELSE 2
END = 0
THEN 0
ELSE
CASE WHEN 6 < 0
THEN 2
ELSE 1
END / (3 + CASE WHEN 5 < 0
THEN 2
ELSE 0
END)
END
I use a below Regex string, but only match without nested expresion:
(CASE WHEN )(?<cond>[\s\S]*?)( THEN )(?<val1>[\s\S]*?)( ELSE )(?<val2>[\s\S]*?)( END)
What regular expression need to extract the first "CASE WHEN" as below?
Condition: 5 + CASE WHEN 6 < 3 THEN 5 ELSE 2 END = 0
Value1: 0
Value2: CASE WHEN 6 < 0 THEN 2 ELSE 1 END / (3 + CASE WHEN 5 < 0 THEN 2 ELSE 0 END)

Select Specific Coordinates From List

I have a list of coordinates (x, y) ordered from left to right, top to bottom:
My goal is to grab only some of them in a different order. I've numbered the only points I want to grab and in the order I want to grab them. Similar to Snake. The direction reverses each time I move down one:
I've attempted writing out the logic for how to select each point, but I can't seem to work out how to get it in a for loop. Or a nested for loop, I think I'll need.
length = 10 (the size of the square of coordinates I'm grabbing. Which is 10x10.)
Increments * +
1) length * 0 + 0 // +0 +0
2) length * 1 + 0 // +1 +0
3) length * 2 + 0 // +1 +0
4) length * 1 + 1 // -1 +1
5) length * 2 + 1 // +1 +0
6) length * 3 + 0 // +1 -1
7) length * 4 + 0 // +1 +0
8) length * 3 + 1 // -1 +1
9) length * 4 + 1 // +1 +0
10) length * 5 + 0 // +1 -1
So if I were to hard code the array for each coordinate I want, I would have:
1) 0
2) 10
3) 20
4) 11
5) 21
6) 30
7) 40
8) 31
9) 41
10) 50

I do not think this requires a nested loop.
You can use a flip variable to change whether or not a specific line is "flipped".
Each row has two indices to be taken
flip alternates between 0 and 1, every two indices (i.e. every row)
On even rows, the first index is length - 1 less than the second index
On odd rows, that relationship is flipped.
public static void Main(string[] args)
{
int length = 11;
for (int i = 0; i < 10; ++ i) {
int flip = (i / 2) % 2;
int index = (i / 2) * length + ((i + flip) % 2) * (length - 1);
Console.WriteLine(index);
}
}
Output:
0
10
11
21
22
32
33
43
44
54

Get sum of time column in sql server

What I tried is:
select cast(sum(datediff(second,0,totalhr))/3600 as varchar(12)) + ':' +
right('0' + cast(sum(datediff(second,0,totalhr))/60%60 as varchar(2)),2) +
':' + right('0' + cast(sum(datediff(second,0,totalhr))%60 as varchar(2)),2) as total
FROM checkinout where YEAR(date)=2019 and MONTH(date)=09 and userid=5
It giving wrong output 112:53:04 the right answer should be 116:30:04

If the totalhr column type is time and the format is hh:mm:ss,
For SQL Server: DATEADD (datepart , number , date )
SELECT DATEADD (ms, SUM (DATEDIFF (ms, '00:00:00.000', totalhr)), '00:00:00.000') AS total
FROM checkinout
WHERE
YEAR(date) = 2019 AND
MONTH(date) = 9 AND
userid = 5;
This function adds a specified number value (as a signed integer) to a specified datepart of an input date value, and then returns that modified value.
the above condition will return the calculated Date and Time but if you want just the hh:mm:ss in two digit format you can use:
SELECT FORMAT(hrs, '0#') + ':' + FORMAT(mins, '0#') + ':' + FORMAT(secs, '0#') as total FROM
(SELECT hrs + (((((mins * 60) + (secs - (secs % 60))) / 60) - ((((mins * 60) + (secs - (secs % 60))) / 60) % 60)) / 60) AS hrs,
(((mins * 60) + (secs - (secs % 60))) / 60) % 60 AS mins,
secs % 60 AS secs
FROM (
SELECT SUM(116) AS hrs, // you have to replace the number with your column
SUM(30) AS mins, // you have to replace the number with your column
SUM(04) AS secs // you have to replace the number with your column
) AS dateSplit) AS total

try running below query
SELECT cast(sum(DATEPART(HOUR,totalhr)) as varchar(max)) + ':' +
cast(sum(DATEPART(MINUTE,totalhr)) as varchar(max)) + ':' +
cast(sum(DATEPART(SECOND,totalhr)) as varchar(max)) FROM checkinout

Get range in multiplication of 5

I have a number. For instance, my number is 19 . Then I want to populate my drop down with range in multiplication of 5. So my dropdownlist will consist of items of:
1-5
6-10
11-15
16-19
I tried modulus and division, however, I can't seems to get the range. Is there a fixed method?
Sample code
List<string> range = new List<string>();
int number = 19;
int numOfOccur = (19/5);
for (int i = 1; i < numOfOccur ; i++)
{
range.Add(i + " - " + (i * 5))
}

Sometime I think that old school code, without fancy linq is a bit more clear
int maximum = 19;
int multiple = 5;
int init = 1;
while (init + multiple <= maximum )
{
string addToDDL = init.ToString() + "-" + (init + multiple - 1).ToString();
Console.WriteLine(addToDDL);
init += multiple;
}
if(init <= maximum)
{
string last = init.ToString() + "-" + maximum.ToString();
Console.WriteLine(last);
}

Linq solution (modern techs allow us to put it consize):
int number = 19;
int div = 5;
List<string> range = Enumerable
.Range(0, number / div + (number % div == 0 ? 0 : 1))
.Select(i => $"{i * div + 1} - {Math.Min((i + 1) * div, number)}")
.ToList();
Test
Console.Write(string.Join(Environment.NewLine, range));
Returns
1 - 5
6 - 10
11 - 15
16 - 19
When using modulo arithmetics, do not forget about remainders: you have an error in int numOfOccur = (19/5); line. It should be
int numOfOccur = 19 / 5 + (19 % 5 == 0 ? 0 : 1);
for the last incomplete 16 - 19 range to be proceeded.

Add this package to your project : https://www.nuget.org/packages/System.Interactive/
Then you can do this:
IEnumerable<IList<int>> buffers2 = Enumerable.Range(1, 19).Buffer(5);
IList<int>[] result2 = buffers2.ToArray();
// { { 1, 2, 3, 4, 5 }, { 6, 7, 8, 9, 10 }, ...
Don't forget to add System.Interactive namespace to your using block.

Wilson Score for 1-5 star rating in C#

I found this really well explained calculation but I really don't know if it's correct or not. I've seen a lot of posts on the subject I havent seen one calculate for 5
the most important part is this:
Stars Negative Positive Total
0 0 0 0
1 1 0 1
2 0.75 0.25 1
3 0.5 0.5 1
4 0.25 0.75 1
5 0 1 1
SET new.total = new.positive + new.negative,
new.stars = ROUND( (((new.positive / new.total) * 4) + 1) * 2, 0) / 2,
new.lower_bound = ((new.positive + 1.9208) / (new.positive + new.negative) - 1.96 * SQRT((new.positive * new.negative) / (new.positive + new.negative) + 0.9604) / (new.positive + new.negative)) / (1 + 3.8416 / (new.positive + new.negative))
which I converted to C# as the following
double posf = model.stars == 1 ? 0 :
model.stars == 2 ? 0.25 :
model.stars == 3 ? 0.5 :
model.stars == 4 ? 0.75 :
model.stars == 5 ? 1 : 0;
double negf = model.stars == 1 ? 1 :
model.stars == 2 ? 0.75 :
model.stars == 3 ? 0.5 :
model.stars == 4 ? 0.25 :
model.stars == 5 ? 0 : 0;
rating.positif += posf;
rating.negatif += negf;
rating.ratingcount += 1;
rating.ratingavg = Math.Round((((rating.positif / rating.ratingcount) * 4) + 1) * 2, 0) / 2;
rating.calcSort = ((rating.positif + 1.9208) / (rating.positif + rating.negatif) - 1.96 * Math.Sqrt((rating.positif * rating.negatif) / (rating.positif + rating.negatif) + 0.9604) / (rating.positif + rating.negatif)) / (1 + 3.8416 / (rating.positif + rating.negatif));
Can someone help me if this coding is correct conversion and if the sql version is actually correct.

You can store the lower-bound value as a double, there is no need to round it. The C# function can be turned into something like this:
private static double WilsonAlgorithm(double positive, double negative)
{
return ((positive + 1.9208) / (positive + negative) -
1.96 * Math.Sqrt((positive * negative) / (positive + negative) + 0.9604) /
(positive + negative)) / (1 + 3.8416 / (positive + negative));
}
(credits to: http://www.evanmiller.org/how-not-to-sort-by-average-rating.html, most of it came from the sql code on his page)
To convert from stars --> positive/negative, you can calculate them without over-using the ternary operator for readability.
// constants
const int maxRating = 5;
const int minRating = 1;
const double shareRating = 0.25;
// conversions
var stars = 5;
var positive = (stars - minRating) * shareRating;
var negative = (maxRating - stars) * shareRating;
// ..
// usage?
var lowerBoundRating = WilsonAlgorithm(totalPositive, totalNegative);