use strict;
use warnings;
use List::Util qw(reduce);
use bignum;

# Number of coins to toss
my $coin_toss=1000;

# We cumulative probability of side1 appearing anywhere between 1 and 60 times
my $side1=60;

# Compute the binomial coefficients for row 1000 of pascal's triangle
my @triangle = robo_2(1000);

print <<EOHDR;
Tails      Count     %
-----   ----------  ------
EOHDR
my $total_prob=0;
my $runs = reduce { $a + $b } @triangle;
for (my $i = 0; $i < @triangle; $i++) {
        my $prob = $triangle[$i]/$runs;
        $total_prob += $prob unless $i > $side1;

        print "$i\t$triangle[$i]\t",100*$prob, "\n";
}

print "\n\nProbability of 0..60 tails is: ", $total_prob*100;

sub robo_2 {
        my $row = shift;
        my @cols = (1);
        ++$row;
        $cols[$_] = $cols[$_-1] * ($row-$_)/$_ for 1 .. $row-1;
        return @cols;
}