diff options
| -rw-r--r-- | challenge-175/adam-russell/blog.txt | 1 | ||||
| -rw-r--r-- | challenge-175/adam-russell/java/ch-1.java | 37 | ||||
| -rw-r--r-- | challenge-175/adam-russell/java/ch-2.java | 65 | ||||
| -rw-r--r-- | challenge-175/adam-russell/perl/ch-1.pl | 31 | ||||
| -rw-r--r-- | challenge-175/adam-russell/perl/ch-2.pl | 42 |
5 files changed, 176 insertions, 0 deletions
diff --git a/challenge-175/adam-russell/blog.txt b/challenge-175/adam-russell/blog.txt new file mode 100644 index 0000000000..9d1352d3f4 --- /dev/null +++ b/challenge-175/adam-russell/blog.txt @@ -0,0 +1 @@ +http://www.rabbitfarm.com/cgi-bin/blosxom/perl/2022/07/30 diff --git a/challenge-175/adam-russell/java/ch-1.java b/challenge-175/adam-russell/java/ch-1.java new file mode 100644 index 0000000000..8f12c0c363 --- /dev/null +++ b/challenge-175/adam-russell/java/ch-1.java @@ -0,0 +1,37 @@ +import java.util.Calendar; + +class LastSunday{ + private static String lastSundayMonth(int month, int year){ + int day = 20; + Calendar c = Calendar.getInstance(); + c.set(year, month, day); + int lastSunday = day; + while(day <= c.getActualMaximum(Calendar.DATE)){ + c.set(Calendar.DATE, day); + if(c.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY) + lastSunday = day; + day++; + } + month++; + String m = String.valueOf(month); + if(month < 10) + m = "0" + m; + return year + "-" + m + "-" + lastSunday; + } + + public static String[] lastSunday(int year){ + int month = 0; + String lastSunday[] = new String[12]; + while(month < 12){ + lastSunday[month] = lastSundayMonth(month, year); + month++; + } + return lastSunday; + } + + public static void main(String[] args){ + String[] lastSunday = lastSunday(2022); + for(int i = 0; i < lastSunday.length; i++) + System.out.println(lastSunday[i]); + } +} diff --git a/challenge-175/adam-russell/java/ch-2.java b/challenge-175/adam-russell/java/ch-2.java new file mode 100644 index 0000000000..15232709ce --- /dev/null +++ b/challenge-175/adam-russell/java/ch-2.java @@ -0,0 +1,65 @@ +import java.util.HashSet; +import java.util.ArrayList; + +class PerfectTotient{ + + private static double EPSILON = 1e-7; + + private static ArrayList primeFactors(int n){ + ArrayList factors = new ArrayList(); + while (n % 2 == 0){ + factors.add(new Integer(2)); + n = n / 2; + } + for(int i = 3; i <= Math.sqrt(n); i = i + 2){ + while (n % i == 0){ + factors.add(new Integer(i)); + n = n / i; + } + } + if(n > 2) + factors.add(new Integer(n)); + return factors; + } + + private static int totient(int n){ + ArrayList factors = new ArrayList(); + factors.addAll(new HashSet(primeFactors(n))); + float totient = n; + for(int i = 0; i < factors.size(); i++){ + totient *= (1 - (1.0 / ((Integer) factors.get(i)).intValue())); + } + return (int) totient; + } + + public static int[] perfectTotients(int n){ + int[] perfectTotients = new int[n]; + int i = 0; + int x = 1; + while(i < n){ + x++; + ArrayList totients = new ArrayList(); + int totient = totient(x); + totients.add(new Integer(totient)); + while(Math.abs(totient - 1) > EPSILON){ + totient = totient(totient); + totients.add(new Integer(totient)); + } + int totientSum = 0; + for(int j = 0; j < totients.size(); j++) + totientSum += ((Integer)totients.get(j)).intValue(); + if(totientSum == x){ + perfectTotients[i] = x; + i++; + } + } + return perfectTotients; + } + + public static void main(String[] args){ + int[] perfectTotients = perfectTotients(20); + for(int i = 0; i < perfectTotients.length - 1; i++) + System.out.print(perfectTotients[i] + ", "); + System.out.println(perfectTotients[perfectTotients.length - 1]); + } +} diff --git a/challenge-175/adam-russell/perl/ch-1.pl b/challenge-175/adam-russell/perl/ch-1.pl new file mode 100644 index 0000000000..be6d9a1582 --- /dev/null +++ b/challenge-175/adam-russell/perl/ch-1.pl @@ -0,0 +1,31 @@ +use strict; +use warnings; +## +# Write a script to list the last sunday of every month in the given year. +## +use Time::Piece; + +sub last_sunday_month{ + my($month, $year) = @_; + $month = "0$month" if $month < 10; + my $sunday; + my $t = Time::Piece->strptime("$month", "%m"); + for my $day (20 .. $t->month_last_day()){ + $t = Time::Piece->strptime("$day $month $year", "%d %m %Y"); + $sunday = "$year-$month-$day" if $t->wday == 1; + } + return $sunday; +} + +sub last_sunday{ + my($year) = @_; + my @sundays; + for my $month (1 .. 12){ + push @sundays, last_sunday_month($month, $year); + } + return @sundays; +} + +MAIN:{ + print join("\n", last_sunday(2022)) . "\n"; +} diff --git a/challenge-175/adam-russell/perl/ch-2.pl b/challenge-175/adam-russell/perl/ch-2.pl new file mode 100644 index 0000000000..2d1209acc6 --- /dev/null +++ b/challenge-175/adam-russell/perl/ch-2.pl @@ -0,0 +1,42 @@ +use strict; +use warnings; +## +# Write a script to generate the first 20 Perfect Totient Numbers. +## +use constant EPSILON => 1e-7; + +sub distinct_prime_factors{ + my $x = shift(@_); + my %factors; + for(my $y = 2; $y <= $x; $y++){ + next if $x % $y; + $x /= $y; + $factors{$y} = undef; + redo; + } + return keys %factors; +} + +sub n_perfect_totients{ + my($n) = @_; + my $x = 1; + my @perfect_totients; + { + $x++; + my $totient = $x; + my @totients; + map {$totient *= (1 - (1 / $_))} distinct_prime_factors($x); + push @totients, $totient; + while(abs($totient - 1) > EPSILON){ + map {$totient *= (1 - (1 / $_))} distinct_prime_factors($totient); + push @totients, $totient; + } + push @perfect_totients, $x if unpack("%32I*", pack("I*", @totients)) == $x; + redo if @perfect_totients < $n; + } + return @perfect_totients; +} + +MAIN:{ + print join(", ", n_perfect_totients(20)) . "\n"; +} |