Programming Quiz

Marc Clifton

OK, reformatted to protect the guilty. Write a function in your favorite language to create a "day view" in an array for a month, like 11/2019. So for that month/year, the array should look like this, where the day numbers not in the month are null or undefined:

                         1    2
3    4    5    6    7    8    9

10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30

My solution in C#, which uses an extension method:

int?[] days = new int?[6 * 7];
var dow = (int)new DateTime(2019, 11, 1).DayOfWeek;
Enumerable.Range(1, DateTime.DaysInMonth(2019, 11)).ForEachWithIndex((idx, n) => days[dow + idx] = n);

And the output function:

days.ForEachWithIndex((idx, n) => Console.Write(((idx % 7 == 0) ? "\r\n" : "") + (n?.ToString()?.PadLeft(5) ?? " ")));

Which of course generates a leading CRLF, but oh well, that wasn't specifically indicated not to do so in the spec. :laugh: For the curious, this came up in a conversation with a coworker.

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RossMW

Is this your homework, sonny.

A Fine is a Tax for doing something wrong A Tax is a Fine for doing something good.

Lost User

Ok, completely not familiar with this stuff, but would ((idx % 7 == 0) && (idx > 0)) ? not prevent from a leading space? :-O

It does not solve my Problem, but it answers my question

Richard Deeming

Now make it work for cultures whose week doesn't start on Sunday. ;P

"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

W Balboos GHB

Richard Deeming wrote:

cultures whose week doesn't start on Sunday.

That's easy - NUKE 'EM !

Ravings en masse^

"The difference between genius and stupidity is that genius has its limits." - Albert Einstein

"If you are searching for perfection in others, then you seek disappointment. If you seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010

Marc Clifton

0x01AA wrote:

&& (idx > 0))

Exactly what I was thinking, I just figured I'd show you what I'd come up with, warts and all. ;)

Latest Articles:
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Marc Clifton

Richard Deeming wrote:

Now make it work for cultures whose week doesn't start on Sunday.

I wonder if there are any cultures that don't have a 7 day week? Or even the concept of a week?

Latest Articles:
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Marc Clifton

RossMW wrote:

Is this your homework, sonny.

Urgentz! Help PLZ!!! ;)

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16 Days: A TypeScript application from concept to implementation

Richard Deeming

Is the 7 day week universal? : NoStupidQuestions[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

PIEBALDconsult

Pfft... I've been using an MS Word template with a macro to create calendars since the mid-90s. With weeks beginning on Monday as per ISO and ISO week numbers as well.

AFell2

Took this a step further and extended the code, and it should work with culture:

void Main()
{
StringBuilder builder = new StringBuilder();

Enumerable.Range(1, 12)
    .ToList()
    .ForEach(e => PopulateDayOfMonth(2021, e, builder));
    
Console.WriteLine(builder.ToString().Trim());

}

static void PopulateDayOfMonth(int year, int month, StringBuilder builder)
{
builder.AppendLine();
int space = 6;
int dashLine = 1 + (space * 7);

IEnumerable days = Enumerable.Range(1, DateTime.DaysInMonth(year, month))
    .Select(d => new DateTime(year, month, d));

builder.AppendLine(days.First().ToString("MMMMM"));
builder.Append('-', dashLine);
builder.AppendLine();
builder.AppendLine($"|{string.Join("|", Enum.GetNames(typeof(DayOfWeek)).Select(d => $" {d.Substring(0, 3)} "))}|" );
builder.Append('-', dashLine);
builder.AppendLine();
DayOfWeek dow = days.First().DayOfWeek;

while (dow != 0)
{
    builder.Append(' ', space);
    dow--;
}

bool first = true;

foreach (var d in days)
{
    if (!first && d.DayOfWeek == 0)
    {
        builder.AppendLine("|");
        builder.Append('-', dashLine);
        builder.AppendLine();
    }

    builder.Append($"|{d.Day.ToString().PadLeft(space - 2)} ");
    first = false;
}

builder.AppendLine("|");
builder.Append('-', dashLine);
builder.AppendLine();

}

With the following output:

January

| Sun | Mon | Tue | Wed | Thu | Fri | Sat |

                          |   1 |   2 |

| 3 | 4 | 5 | 6 | 7 | 8 | 9 |

| 10 | 11 | 12 | 13 | 14 | 15 | 16 |

| 17 | 18 | 19 | 20 | 21 | 22 | 23 |

| 24 | 25 | 26 | 27 | 28 | 29 | 30 |

| 31 |

February

| Sun | Mon | Tue | Wed | Thu | Fri | Sat |

  |   1 |   2 |   3 |   4 |   5 |   6 |

| 7 | 8 | 9 | 10 | 11 | 12 | 13 |

Member 11005478

Sunday is part of the weekend. That's a clue as to the correct day that a week starts on

BillWoodruff

:thumbsup:

«One day it will have to be officially admitted that what we have christened reality is an even greater illusion than the world of dreams.» Salvador Dali

EliaMelfior

This could be a fun little puzzle. I just get tired thinking about solving it, i would have to search for a time library in javascript/php, and then format the output nicely. Just not in the mood for a little puzzle, does anyone identify with this feeling sometimes? Nice quiz though.

ZurdoDev

Member 11005478 wrote:

weekend. That's a clue as to the correct day that a week starts on

Just like bookends are all on one side. :laugh:

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Stuart Dootson

In Haskell (because, of course Haskell!): ```haskell import Data.List.Split import Data.Time.Calendar; import Data.Time.Calendar.Compat; import Data.Time.Calendar.Julian; import Text.Printf printMonth :: Integer -> Int -> IO () printMonth year month = printWeeks entriesInMonth where -- printWeeks chunks the month's entries into weeks & prints each week on a new line printWeeks days = mapM_ (putStrLn.unwords) (chunksOf 7 days) -- entriesInMonth concatenates the empty entries at the start of the month with the days entriesInMonth = startPadding ++ daysOfMonth -- daysOfMonth generates a list of days of the month as strings daysOfMonth = map (printf "%2d") [1..(julianMonthLength year month)] -- startPadding generates blank strings for each empty entry before day '1' startPadding = replicate blanksBeforeDay1 " " -- blanksBeforeDay1 is the number of empty entries before day '1' blanksBeforeDay1 = (fromEnum $ dayOfWeek (fromJulian year month 1)) `mod` 7 ``` which gives: ``` > printMonth 2019 12 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 > printMonth 20190 12 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 > printMonth 20190 11 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 ``` [ETA] That's using the Julian calendar - the standard Gregorian calendar can be used by replacing the word 'julian' or 'Julian' with 'gregorian'/'Gregorian'. And yes, I should be able to remember which calendar we use :-O [/ETA]

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Jorgen Andersson

So, I don't know shit about Haskell, but shouldn't it be Data.Time.Calendar.Gregorian instead of Data.Time.Calendar.Julian? Unless you're living in Russia that is.

Wrong is evil and must be defeated. - Jeff Ello

Jorgen Andersson

Otherwise you could use Genesis 2.2 as a reference.

Wrong is evil and must be defeated. - Jeff Ello

ZurdoDev

Jörgen Andersson wrote:

Otherwise you could use Genesis 2.2 as a reference.

Correct. The Old Testament week.

Social Media - A platform that makes it easier for the crazies to find each other. Everyone is born right handed. Only the strongest overcome it. Fight for left-handed rights and hand equality.

agolddog

Checkin rejected, hard-coded values. Just kidding, the knuckleheads I work with hard-code things all over the place, and management won't let us have any code reviews. Sigh.