Re: John Guttag's book - 2nd exercise. My attempt in Perl.

[kcott]

G'day pritesh_ugrankar,

Here's one way to do it:

#!/usr/bin/env perl

use strict;
use warnings;
use constant { INPUT => 0, EXPECT => 1, NO_ODDS => 'no odds found' };

use Test::More;

my @tests = (
    [[qw{-11 -13 4}], -11],
    [[qw{-12 -14 4}], NO_ODDS],
    [[qw{0 0 0}], NO_ODDS],
    [[qw{1 1 1}], 1],
    [[qw{1 0 1}], 1],
    [[qw{0 0 1}], 1],
    [[qw{2 3 2}], 3],
    [[qw{2 -3 2}], -3],
    [[qw{-2 -3 -4}], -3],
    [[qw{-1 -3 -5}], -1],
    [[qw{3 5 7}], 7],
    [[qw{7 5 3}], 7],
    [[qw{5 7 3}], 7],
);

plan tests => scalar @tests;

for my $test (@tests) {
    my ($x, $y, $z) = @{$test->[INPUT]};

    my $u = ($x, $y)[$x % 2 ? ($y % 2 ? $x < $y : 0) : 1];
    my $v = ($u, $z)[$u % 2 ? ($z % 2 ? $u < $z : 0) : 1];
    ok((NO_ODDS, $v)[$v % 2] eq $test->[EXPECT]);
}

See Test::More if you're not familiar with that module. It's very useful in situations like this where you want to test a solution against a variety of input data.

All those tests passed:

1..13
ok 1
... 2 to 12 all 'ok' also ...
ok 13

As you can hopefully see, it's very easy to add more test data by simply adding more elements to @tests.