Here's a slightly speedier alternative to get Pascal's triangle row for the number of tosses:
sub pascal_tri_row {
my $r = shift;
return () if $r < 0;
my @row = (1) x ($r + 1);
for my $i (1 .. $r - 1)
{
$row[$_] += $row[$_ - 1]
for reverse 1 .. $i;
}
return @row;
}
sub triangle {
my $numTosses = shift;
my @triangle = (0, 1, 0);
for (1 .. $numTosses) {
my @newTriangle=(0);
push @newTriangle, $triangle[$_]+$triangle[$_+1] for 0 .. $#tr
+iangle-1;
push @newTriangle, 0;
@triangle = @newTriangle;
}
return @triangle;
}
use Benchmark qw(cmpthese);
cmpthese -1, {
robo_tri => sub { triangle(32) },
repel_tri => sub { 0, pascal_tri_row(32), 0 }, # 0's to match tria
+ngle()'s return
};
__END__
Rate robo_tri repel_tri
robo_tri 1128/s -- -38%
repel_tri 1811/s 60% --
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