Doomsday rule: Difference between revisions

Add Scala implementation
m (→‎{{header|FORTRAN}}: RC uses Fortran, not FORTRAN)
(Add Scala implementation)
Line 1,793:
2077-02-12: Friday
2101-04-02: Saturday
</pre>
 
=={{header|Scala}}==
{{trans|Java}}
<syntaxhighlight lang="Scala">
object Doom extends App {
val dates = Array(
new Date(1800, 1, 6),
new Date(1875, 3, 29),
new Date(1915, 12, 7),
new Date(1970, 12, 23),
new Date(2043, 5, 14),
new Date(2077, 2, 12),
new Date(2101, 4, 2)
)
 
dates.foreach(d => println(s"${d.format}: ${d.weekday}"))
}
 
class Date(val year: Int, val month: Int, val day: Int) {
import Date._
 
def isLeapYear: Boolean = year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)
 
def format: String = f"$month%02d/$day%02d/$year%04d"
 
def weekday: String = {
val c = year / 100
val r = year % 100
val s = r / 12
val t = r % 12
 
val cAnchor = (5 * (c % 4) + 2) % 7
val doom = (s + t + t / 4 + cAnchor) % 7
val anchor = if (isLeapYear) leapdoom(month - 1) else normdoom(month - 1)
 
weekdays((doom + day - anchor + 7) % 7)
}
}
 
object Date {
private val leapdoom = Array(4, 1, 7, 4, 2, 6, 4, 1, 5, 3, 7, 5)
private val normdoom = Array(3, 7, 7, 4, 2, 6, 4, 1, 5, 3, 7, 5)
val weekdays = Array("Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday")
}
</syntaxhighlight>
{{out}}
<pre>
01/06/1800: Monday
03/29/1875: Monday
12/07/1915: Tuesday
12/23/1970: Wednesday
05/14/2043: Thursday
02/12/2077: Friday
04/02/2101: Saturday
 
</pre>
 
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