Topic: -={ Challenge }=- Doomsday Algorithm

[ElpanovEvgeniy]

Code - Auto/Visual Lisp: [Select]

1. (defun ee_getday (y m d / a)
2.   (setq y (- y (setq a (/ (- 14 m) 12))))
3.   (nth (rem (+ d y (/ y 4) (/ y -100) (/ y 400) (/ (* 31 (+ m (* 12 a) -2)) 12)) 7)
4.        '("Sunday" "Monday" "Tuesday" "Wednesday" "Thursday" "Friday" "Saturday")
5.   )
6. )

[Lee Mac]

 

Code: [Select]

_$ (keith_doomsday 1812 2 20)
"Thursday"
_$ (pBe_getday 1812 2 20)
"Thursday"
_$ (lm:getday 1812 2 20)
"Thursday"
_$ (ee_getday 1812 2 20)
"Thursday"

Code - Auto/Visual Lisp: [Select]

1. Benchmarking ..................Elapsed milliseconds / relative speed for 32768 iteration(s):
2.  
3.     (EE_GETDAY 1812 2 20)..........1155 / 2.88 <fastest>
4.     (LM:GETDAY 1812 2 20)..........1170 / 2.84
5.     (KEITH_DOOMSDAY 1812 2 20).....1248 / 2.66
6.     (PBE_GETDAY 1812 2 20).........3323 / 1 <slowest>

It wouldn't be right if Evgeniy wasn't at the top

[ElpanovEvgeniy]

Code - Auto/Visual Lisp: [Select]

1. _$
2. Benchmarking ...................Elapsed milliseconds / relative speed for 65536 iteration(s):
3.  
4.     (LEE_GETDAY 2012 5 11).....1513 / 1 <fastest>
5.     (EE_GETDAY 2012 5 11)......1513 / 1 <slowest>
6.  
7.  
8. _$

[ElpanovEvgeniy]

It wouldn't be right if Evgeniy wasn't at the top

Why?   

[Lee Mac]

It wouldn't be right if Evgeniy wasn't at the top

Why?   

Because we measure the awesomeness of our codes on a scale from 0 to Evgeniy 

[ElpanovEvgeniy]

Now, my code was very similar to yours! 

[LE3]

after to much lurking... here is something extracted from one of my old classes arxKey - just to put a little pepper on the lisp salad.-

Code - C++: [Select]

1. // returns same left value as:
2. // acedGetVar(_T("DATE"), &rb)
3. // acdbRToS(r, 2, 12, fmtval);
4. long JulianDayNumber (int y, int m, int d)
5. {
6.         if (m < 3) { y--; m += 12; }
7.         y += 8000;
8.         return (y * 365) + (y / 4) - (y / 100) + (y / 400) + (m * 153 + 3) / 5 - 92 + d - 1 - 1200820;
9. }
10. [code]
11. [code=cpp]
12. static void LESQ_TST(void)
13. {
14.         //long val = JulianDayNumber(2012, 5, 11);
15.         long val = JulianDayNumber(1812, 2, 20);
16.         int dayOfWeek = val % 7 + 1;
17.         AcString day;
18.         switch (dayOfWeek)
19.         {
20.         case 1: day = _T("Monday"); break;
21.         case 2: day = _T("Tuesday"); break;
22.         case 3: day = _T("Wendsday"); break;
23.         case 4: day = _T("Thursday"); break;
24.         case 5: day = _T("Friday"); break;
25.         case 6: day = _T("Saturday"); break;
26.         case 7: day = _T("Sunday"); break;
27.         }
28.         acutPrintf (_T("\nDay of the week[%s] \n"), day.kACharPtr());
29. }
30.  

[Keith™]

You know this is so much easier in C++ or C#

[Lee Mac]

You know this is so much easier in C++ or C#

Indeed, a single line. 

[LE3]

^ indeed for many things - but not for everything (at least in c++) - per all the stuff i have done so far..

[Keith™]

I was thinking more on the lines of creating a time struct, passing the date values then outputting the day.

[Kerry]

Almost a one-liner

[Lee Mac]

Very nice Kerry - out of interest, can that method handle dates occurring before 1900 (as per Evgeniy's example), as I know that is a limitation for some systems.

Also, I like your VS colour scheme, though not sure about the 'blue screen of death' style console 

[Kerry]

The DateTime value type represents dates and times with values ranging from 12:00:00 midnight, January 1, 0001 Anno Domini (Common Era) through 11:59:59 P.M., December 31, 9999 A.D. (C.E.).

Yes, I like that colour Scheme. http://www.theswamp.org/index.php?topic=41700.msg468090#msg468090

The 'Blue Screen' is just me being rebellious

[Lee Mac]

Excellent