#!/usr/bin/perl -w

use strict;

my $pat = '"%d %s %d is %d" if (%d %s %d == %d)'; 

matchIf($pat, 3, '+', 4, 7);
matchIf($pat, 5, '*', 4, 20);
matchIf($pat, 5, '%', 4, 20);
matchIf($pat, 5, '-', 4, 20);

sub matchIf {
	my ($pat, $x, $op, $y, $z) = @_;
	my $foo =  sprintf($pat, $x, $op, $y, $z, $x, $op, $y, $z);
	print eval ($foo),"\n";
}


##</code><code>##


#!/usr/bin/perl -w

use strict;

my $pat = '"%d %s %d is %d" if (%d %s %d == %d)'; 
my $order = '[$_[0], $_[1], $_[2], $_[3]]';

matchIf($pat, $order, 3, '+', 4, 7);
matchIf($pat, $order, 5, '*', 4, 20);
matchIf($pat, $order, 5, '%', 4, 20);
matchIf($pat, $order, 5, '-', 4, 20);

sub matchIf {
	my ($pat, $order) = (shift, shift);
        print eval sprintf($pat, @{eval $order}, @{eval $order}), "\n";

}