Minkowski question-mark function: Difference between revisions

=={{header|Raku}}==

{{trans|Go}}

<lang perl6># 20201120 Raku programming solution

my \MAXITER = 151;

sub minkowski(\x) {

return x.floor + minkowski( x - x.floor ) if x > 1 || x < 0 ;

my $y = my $p = x.floor;

my ($q,$s,$d) = 1 xx 3;

my $r = $p + 1;

loop {

last if ( $y + ($d /= 2) == $y ) ||

( my $m = $p + $r) < 0 | $p < 0 ||

( my $n = $q + $s) < 0 ;

x < $m/$n ?? ( ($r,$s) = ($m, $n) ) !! ( $y += $d; ($p,$q) = ($m, $n) );

}

return $y + $d

}

sub minkowskiInv($x is copy) {

return $x.floor + minkowskiInv($x - $x.floor) if $x > 1 || $x < 0 ;

return $x if $x == 1 || $x == 0 ;

my @contFrac = 0;

my $i = my $curr = 0 ; my $count = 1;

loop {

$x *= 2;

if $curr == 0 {

if $x < 1 {

$count++

} else {

$i++;

@contFrac.append: 0;

@contFrac[$i-1] = $count;

($count,$curr) = 1,1;

$x--;

}

} else {

if $x > 1 {

$count++;

$x--;

} else {

$i++;

@contFrac.append: 0;

@contFrac[$i-1] = $count;

($count,$curr) = 1,0;

}

}

if $x == $x.floor { @contFrac[$i] = $count ; last }

last if $i == MAXITER;

}

my $ret = 1 / @contFrac[$i];

loop (my $j = $i - 1; $j ≥ 0; $j--) { $ret = @contFrac[$j] + 1/$ret }

return 1 / $ret

}

printf "%19.16f %19.16f\n", minkowski(0.5*(1 + 5.sqrt)), 5/3;

printf "%19.16f %19.16f\n", minkowskiInv(-5/9), (13.sqrt-7)/6;

printf "%19.16f %19.16f\n", minkowski(minkowskiInv(0.718281828)),

minkowskiInv(minkowski(0.1213141516171819))</lang>

{{out}}

<pre> 1.6666666666696983 1.6666666666666667

-0.5657414540893351 -0.5657414540893352

0.7182818280000092 0.1213141516171819</pre>