print("\n");
print("-" x 35, "\n");
print("Challenge 1. Determine max or min values of a list with the numbers 0 7 5 3 22 23 11 34 51 32 5 3 1\n");
print("-" x 35, "\n");

use List::Util qw(max min);
@numbers_list = qw( 0 7 5 3 22 23 11 34 51 32 5 3 1 );
print("Highest number: " . max(@numbers_list) . "\n");
print("Lowest number: " . min(@numbers_list) . "\n");
print("-" x 35, "\n");

print("\n");
print("-" x 35, "\n");
print("Challenge 2. Determine the character with the lowest or highest ASCII value of a list with the characters z, c, m ");
print("-" x 35, "\n");
use List::Util qw(minstr maxstr);
 
print("Character with lowest ASCII value: " . minstr( 'z', 'c', 'm' ) . "\n");
print("Character with highest ASCII value: " . maxstr( 'z', 'c', 'm' ) . "\n");
print("-" x 35, "\n");

print("\n");
print("-" x 35, "\n");
print("Challenge 3. How do two strings differ?");
print("-" x 35, "\n");
use String::Diff;

my($str_1, $str_2) = String::Diff::diff('abcefgijk', 'abcdefghijk');
print "$str_1\n"; # abcefgijk
print "$str_2\n"; # abc{d}efg{h}ijk
print("-" x 35, "\n");

print("\n");
print("-" x 35, "\n");
print("Challenge 4. What do the two arrays ('a b c d' and 'c d e f') have in common and how do these arrays differ?");
print("-" x 35, "\n");

use Array::Utils qw(:all);

@a = qw( a b c d );
@b = qw( c d e f );

@intersection = intersect(@a, @b);
print("items that \@a and \@b share: @intersection\n");

@minus = array_minus( @a, @b );
print("items of \@a that are not in \@b: @minus\n");

@minus = array_minus( @b, @a );
print("items of \@b that are not in \@a: @minus\n");

print("-" x 35, "\n");

use HTML::Entities;
$str_french = "Voilà un gâteau étonnant à la crème brûlée, dégusté à côté d'une île mystérieuse près du cœur de la forêt.";
print (encode_entities($str_french), "\n");

$str_hyperlink = 'arcolinux.com';
print (encode_entities($str_hyperlink), "\n");

use POSIX;

$float = 3.5;
$ceil   = ceil($float); 
print("result 'use POSIX': $ceil\n"); # 4
$floor  = floor($float);  
print("result 'use POSIX': $floor\n"); # 3

$float = -3.5;
$ceil   = ceil($float); 
print("result 'use POSIX': $ceil\n"); # -3
$floor  = floor($float);  
print("result 'use POSIX': $floor\n"); # -4

use Math::Round qw( :all );

$float = 3.5;
$rounded = round($float);
print("result 'use Math': $rounded\n"); # 4

$float = -3.5;
$rounded = round($float);
print("result 'use Math': $rounded\n"); # -4

# without module, with regex

$str = "  Hello World!   ";
$str =~ s/\s+//g;
print("Result: |" . $str . "|\n"); 

# with module 'String::Util' qw(:all)

use String::Util qw(:all);
$str = "  Hello World!   ";
print("Result: |" . nospace($str) . "|\n"); 

# in addition, the module has more interesting features as 'collapse', 'contains', 'startswith', 'endswith', 'sanitize'...

use Path::Tiny;

$number_words = 0;
$total_length_words = 0;
$total_space = 0;

$file = path("./lorem_ipsum.txt");
if ( $file->exists ) {

    @lines = $file->lines; # or @lines = $file->lines_utf8;

    chomp(@lines);

    foreach $line (@lines) {
	
      $line =~ s/\h+/ /g;	

# not necessary...  
      $count_space = () = $line =~ / /g;
      $total_space += $count_space; 
# ...
  
      @single_line = split(/ /, $line);
      $number_words += scalar(@single_line);	

      foreach $word (@single_line) {
        $total_length_words += length($word); 
      }	
    }  

    print("Number of words: $number_words\n");
    print("Number of characters (without space): $total_length_words\n");
    print("Number of spaces: " . $total_space . "\n");
    # print("Number of spaces: " . ($number_words - 1) . "\n");
    print("Average word length: " . $total_length_words / $number_words . "\n");
    
}
else {
    print("$file does not exist.\n");
}    

use Path::Tiny;

$file = path("./lorem_ipsum.txt");	

if ( $file->exists ) {

    $file->copy("./lorem_ipsum.copy.txt");	
  
    $all_text = $file->slurp; # or $all_text = $file->slurp_utf8;
    $all_text =~ s/[a-d]/x/g;
    $file->spew($all_text);
    
} 
else {
    print("$file does not exist.\n");
}

use Text::ASCII::Convert;

$non_ASCII_text = "Árvíztűrő tükörfúrógép, gyönyörű élményekkel teli hétvégét kívánok! 😊🌈🎉";
$text_converted = convert_to_ascii($non_ASCII_text);
 
print("$text_converted\n"); # prints "Arvizturo tukorfurogep, gyonyoru elmenyekkel teli hetveget kivanok!"

use Format::Util::Numbers qw( commas to_monetary_number_format roundnear);

print("12.6789012 -> ". roundnear( 0.01, 12.6789012) . "\n"); # => 12.68
print("-12.6789012 -> ". roundnear( 0.01, -12.6789012) . "\n"); # => -12.68

print("12.6789012 -> ". roundnear( 0.1, 12.6789012) . "\n"); # => 12.7
print("-12.6789012 -> ". roundnear( 0.1, -12.6789012) . "\n"); # => -12.7

print("12345.679 -> ". commas(12345.679, 1) . "\n"); # => 12,345.7

print("123456789 -> ". to_monetary_number_format(123456789) . "\n"); # => 123,456,789.00

	
# content scores.csv with one blank line
# Sebastian;4.5;6.0;7.2
# Daniel;5.5;6.5;7.0
# 
# Florence;7.1;7.9;7.8

use Path::Tiny;
use Format::Util::Numbers qw( roundnear );

use Text::CSV;
$csv = Text::CSV->new({ sep_char => ';' });
 
$file = path("./scores.csv");
if ( $file->exists ) {	
 
   $sum = 0;
   $count = 0;
   $row = 0;

    @lines = $file->lines;

    chomp(@lines);

    foreach $line (@lines) {   
      
      if($line) {
		  
          $row++;
          
          if ($csv->parse($line)) {
          
              @fields = $csv->fields();
              for ($i = 1; $i <= 3; $i++) 
              {
                if ($fields[$i]) {
                  $sum += $fields[$i]; 
                  $count++;
                }    
              }  
          } 
          else {
            die("Line could not be parsed: $line\n");
          }
     }
   }
   print("The average math score of $row students: " . roundnear( 0.1, $sum / $count) . "\n");

}
else {

    print("$file does not exist.\n");	
}

	
use List::MoreUtils qw(each_array);

@array1 = ('a', 'b', 'c', 'd');
@array2 = (1, 2, 3, 4);

# Create an iterator for the arrays
$iter = each_array(@array1, @array2);

# Loop through the arrays simultaneously
while ( ($elem1, $elem2) = $iter->() ) {
    print "$elem1$elem2";
}
print("\n");

	
use Term::Size;
 
($columns, $rows) = Term::Size::chars *STDOUT{IO};

die "Need 80 column screen" if ($columns < 80);

$screen_width = $columns;

$str = "We know what we are, but not what we may be.";
$len = length($str);
$empty = int( ($screen_width - $len) / 2);

print("*" x $screen_width . "\n");
print(" " x $empty);
print($str);
print(" " x $empty . "\n");
print("*" x $screen_width);
print("\n");