#! /usr/bin/perl -wl

# sum of the numbers in series 1..n that are multiple of either 3 or 5

use List::Util qw(sum sum0);

sub f1 {
    sum0 grep { $_ % 3 == 0 or $_ % 5 == 0 } 1 .. shift;
}

sub f2 {
    sum map { $_ * (map $_*($_+1)/2, int $_[0]/abs)[0] } (3, 5, -15);
}

# while (<>) {...}
for (1 .. 23) {
    print join ' ', $_, f1($_), f2($_);
}

##</code><code>##

sub f3 {
    my $n    = shift;

    my $t3   =  3 * int($n/3) * int($n/3 + 1) / 2;
    my $t5   =  5 * int($n/5) * int($n/5 + 1) / 2;
    my $t15  = 15 * int($n/15) * int($n/15 + 1) / 2;

    return $t3 + $t5 - $t15;
}