Update: THIS IS A WRONG IMPLEMENTATION. PLease don't++ it!! Thanks, buk.
I'm getting different results from other people, so this is probably wrong, but then maybe not, so...
#! perl -slw
use strict;
use List::Util qw[ reduce ];
$a = $a; ## Disable the dumbest warning in perl!
my @samples = (
## r1 r2 r3
[ qw[ 0.11 0.07 0.19 ] ],
[ qw[ 0.43 0.31 0.37 ] ],
[ qw[ 0.93 0.78 0.82 ] ],
[ qw[ 0.91 0.12 0.15 ] ],
[ qw[ 0.52 0.18 0.32 ] ],
);
sub P{
return 1 if @_ == 1;
my @r = @_;
return reduce {
$a + ( $r[ $b ] - $r[ $b - 1 ] ) * P( @r[ 0 .. ( $#r - $b ) ]
+ )
} 0 .. $#r;
}
my @results = map P( @$_ ), @samples;
print "@results";
__END__
P:\test>380259
0.1216 0.0744 0.0624999999999999 0.6541 0.2556
Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail
"Memory, processor, disk in that order on the hardware side. Algorithm, algorithm, algorithm on the code side." - tachyon