gistfile1.pl

use strict;
use warnings;

use Test::More;

sub sample1 {
    my ( $a, $b ) = @_;
    if ( !$a && !$b ) {
        return "hello";
    }
    else {
        return "world";
    }
}

# ドモルガンの法則で簡素化せよ
sub answer1_1 {
    my ( $a, $b ) = @_;
    unless ( $a || $b ) {
        return "hello";
    }
    else {
        return "world";
    }
}

# 関数切り出しで簡素化せよ
sub answer1_2 {
    my ( $a, $b ) = @_;
    if ( is_enable($a, $b) ) {
        return "hello";
    }
    else {
        return "world";
    }
}

sub is_enable {
	my ( $a, $b ) = @_;
	return !( $a || $b );
}

sub sample2 {
    my ( $a, $b, $c ) = @_;
    if ( !$c ) {
        if ( !$a && !$b ) {
            return "hello";
        }
        else {
            return "world";
        }
    }
    return ( $a or $b );
}

# ガード節でネストを下げよ
sub answer2 {
    my ( $a, $b, $c ) = @_;
	if ( $c ) {
		return ( $a or $b )
	}

	unless ( $a or $b ) {
		return "hello";
	}
	else {
		return "world";
	}
}

sub sample3 {
    my ( $a, $b, $c, $d ) = @_;

    if ( $a && $b && !$c && !$d) {
        return "a and b";
    }
    if ( $a && !$b && $c && !$d) {
        return "a and c";
    }
    if ( $a && !$b && !$c && $d) {
        return "a and d";
    }
    if ( !$a && $b && $c && !$d) {
        return "b and c";
    }
    if ( !$a && $b && !$c && $d) {
        return "b and d";
    }
    if ( !$a && !$b && $c && $d) {
        return "c and d";
    }
    return $a+$b+$c+$d;

}

#　制御をデータ構造に置き換えて簡素化せよ
sub answer3{
    my ( $a, $b, $c, $d ) = @_;
	my %table = (
		$a => "a",
		$b => "b",
		$c => "c",
		$d => "d"
	);
	my @trues = grep {$_} @_;
	return "$table{$trues[0]} and $table{$trues[1]}" if @trues == 2;
    return $a+$b+$c+$d;

}
sub check_bool_eq {
    my ( $num, $func_a, $func_b ) = @_;
    for my $s ( 1 .. 2**$num ) {
        my @args = map { $s & ( 1 << $_ ) } ( 1 .. $num );
        is( $func_a->(@args), $func_b->(@args) );

    }
}

check_bool_eq( 2, \&sample1, \&answer1_1 );
check_bool_eq( 2, \&sample1, \&answer1_2 );

check_bool_eq( 3, \&sample2, \&answer2 );
check_bool_eq( 4, \&sample3, \&answer3 );


::done_testing;