Perl & Raku solutions to Tasks 1 & 2 for Week 251

4 files changed, 1031 insertions, 0 deletions

diff --git a/challenge-251/athanasius/perl/ch-1.pl b/challenge-251/athanasius/perl/ch-1.pl
new file mode 100644
index 0000000000..e946765634
--- /dev/null
+++ b/challenge-251/athanasius/perl/ch-1.pl
@@ -0,0 +1,205 @@
+#!perl
+
+################################################################################
+=comment
+
+Perl Weekly Challenge 251
+=========================
+
+TASK #1
+-------
+*Concatenation Value*
+
+Submitted by: Mohammad S Anwar
+
+You are given an array of integers, @ints.
+
+Write a script to find the concatenation value of the given array.
+
+The concatenation of two numbers is the number formed by concatenating their
+numerals.
+
+  For example, the concatenation of 10, 21 is 1021.
+  The concatenation value of @ints is initially equal to 0.
+  Perform this operation until @ints becomes empty:
+
+  If there exists more than one number in @ints, pick the first element
+  and last element in @ints respectively and add the value of their
+  concatenation to the concatenation value of @ints, then delete the
+  first and last element from @ints.
+
+  If one element exists, add its value to the concatenation value of
+  @ints, then delete it.
+
+Example 1
+
+  Input: @ints = (6, 12, 25, 1)
+  Output: 1286
+
+  1st operation: concatenation of 6 and 1 is 61
+  2nd operation: concaternation of 12 and 25 is 1225
+
+  Concatenation Value => 61 + 1225 => 1286
+
+Example 2
+
+  Input: @ints = (10, 7, 31, 5, 2, 2)
+  Output: 489
+
+  1st operation: concatenation of 10 and 2 is 102
+  2nd operation: concatenation of 7 and 2 is 72
+  3rd operation: concatenation of 31 and 5 is 315
+
+  Concatenation Value => 102 + 72 + 315 => 489
+
+Example 3
+
+  Input: @ints = (1, 2, 10)
+  Output: 112
+
+  1st operation: concatenation of 1 and 10 is 110
+  2nd operation: only element left is 2
+
+  Concatenation Value => 110 + 2 => 112
+
+=cut
+################################################################################
+
+#--------------------------------------#
+# Copyright © 2024 PerlMonk Athanasius #
+#--------------------------------------#
+
+#===============================================================================
+=comment
+
+Assumption
+----------
+The input integers are unsigned (i.e., non-negative).
+
+Rationale: If the right hand side of a concatenation is a negative integer, then
+the result of the concatenation will not be an integer. (For example, "3" con-
+catenated with "-45" gives "3-45", which is not an integer.) The simplest way to
+avoid this possibility is to disallow negative numbers in the input.
+
+Interface
+---------
+If no command-line arguments are given, the test suite is run.
+
+=cut
+#===============================================================================
+
+use v5.32.1;       # Enables strictures
+use warnings;
+use Const::Fast;
+use Regexp::Common qw( number );
+use Test::More;
+
+const my $USAGE => <<END;
+Usage:
+  perl $0 [<ints> ...]
+  perl $0
+
+    [<ints> ...]    A non-empty list of unsigned integers
+END
+
+#-------------------------------------------------------------------------------
+BEGIN
+#-------------------------------------------------------------------------------
+{
+    $| = 1;
+    print "\nChallenge 251, Task #1: Concatenation Value (Perl)\n\n";
+}
+
+#===============================================================================
+MAIN:
+#===============================================================================
+{
+    if (scalar @ARGV == 0)
+    {
+        run_tests();
+    }
+    else
+    {
+        my   @ints = @ARGV;
+
+        for (@ints)
+        {
+            / ^ $RE{num}{int} $ /x or error( qq["$_" is not a valid integer] );
+
+            $_ >= 0                or error( "$_ is negative" );
+        }
+
+        printf "Input:  \@ints = (%s)\n",  join ', ', @ints;
+
+        my $concat_value = find_concatenation_value( \@ints );
+
+        print  "Output: $concat_value\n";
+    }
+}
+
+#-------------------------------------------------------------------------------
+sub find_concatenation_value
+#-------------------------------------------------------------------------------
+{
+    my ($ints)        = @_;
+    my  $concat_value = 0;
+
+    while (@$ints)
+    {
+        # Addition of 0 normalizes an integer; for example, "+234" becomes "234"
+
+        if (scalar @$ints == 1)
+        {
+            $concat_value +=  0 + shift @$ints;
+        }
+        else
+        {
+            $concat_value += (0 + shift @$ints) . (0 + pop @$ints);
+        }
+    }
+
+    return $concat_value;
+}
+
+#-------------------------------------------------------------------------------
+sub run_tests
+#-------------------------------------------------------------------------------
+{
+    print "Running the test suite\n";
+
+    while (my $line = <DATA>)
+    {
+        chomp $line;
+
+        my  ($test_name, $ints_str, $expected) = split / \| /x, $line;
+
+        for ($test_name, $ints_str, $expected)
+        {
+            s/ ^ \s+   //x;
+            s/   \s+ $ //x;
+        }
+
+        my @ints         = split / \s+ /x, $ints_str;
+        my $concat_value = find_concatenation_value( \@ints );
+
+        is $concat_value, $expected, $test_name;
+    }
+
+    done_testing;
+}
+
+#-------------------------------------------------------------------------------
+sub error
+#-------------------------------------------------------------------------------
+{
+    my ($message) = @_;
+
+    die "ERROR: $message\n$USAGE";
+}
+
+################################################################################
+
+__DATA__
+Example 1| 6 12 25 1    |1286
+Example 2|10  7 31 5 2 2| 489
+Example 3| 1  2 10      | 112
diff --git a/challenge-251/athanasius/perl/ch-2.pl b/challenge-251/athanasius/perl/ch-2.pl
new file mode 100644
index 0000000000..1d521c3619
--- /dev/null
+++ b/challenge-251/athanasius/perl/ch-2.pl
@@ -0,0 +1,307 @@
+#!perl
+
+################################################################################
+=comment
+
+Perl Weekly Challenge 251
+=========================
+
+TASK #2
+-------
+*Lucky Numbers*
+
+Submitted by: Mohammad S Anwar
+
+You are given a m x n matrix of distinct numbers.
+
+Write a script to return the lucky number, if there is one, or -1 if not.
+
+  A lucky number is an element of the matrix such that it is
+  the minimum element in its row and maximum in its column.
+
+Example 1
+
+  Input: $matrix = [ [ 3,  7,  8],
+                     [ 9, 11, 13],
+                     [15, 16, 17] ];
+  Output: 15
+
+  15 is the only lucky number since it is the minimum in its row
+  and the maximum in its column.
+
+Example 2
+
+  Input: $matrix = [ [ 1, 10,  4,  2],
+                     [ 9,  3,  8,  7],
+                     [15, 16, 17, 12] ];
+  Output: 12
+
+Example 3
+
+  Input: $matrix = [ [7, 8],
+                     [1, 2] ];
+  Output: 7
+
+=cut
+################################################################################
+
+#--------------------------------------#
+# Copyright © 2024 PerlMonk Athanasius #
+#--------------------------------------#
+
+#===============================================================================
+=comment
+
+Interface
+---------
+If no command-line arguments are given, the test suite is run.
+
+Assumptions
+-----------
+Since -1 is returned on failure, elements of the input matrix are limited to
+non-negative numbers. For convenience, they are in addition limited to integers.
+
+Algorithm
+---------
+This is a simple search for a lucky number: if one is found, it is immediately
+returned, otherwise after the search has completed -1 is returned.
+
+In fact, there can only ever be one lucky number for a given matrix. Proof (by
+contradiction):
+
+1. Let element x = matrix(i, j) be a lucky number. Can there be another lucky
+   number in the same matrix?
+
+2. Assume there is a lucky number y = matrix(k, l) with k ≠ i and l ≠ j.
+
+3. Let w = matrix(i, l). Since x is the smallest element in row i, w > x.
+   And since y is the largest element in column l, y > w. So, y > w > x, and by
+   transitivity, y > x (a).
+
+4. Let z = matrix(k, j). Since x is the largest element in column j, z < x.
+   And since y is the smallest element in row k, y < z. So, y < z < x, and by
+   transitivity, y < x (b).
+
+5. Relations (a) and (b) are mutually contradictory, therefore the assumption
+   made in step 2 must be false. QED.
+
+Note
+----
+This solution incorporates or adapts code used in the solution of Task 2 for
+Challenge 248.
+
+=cut
+#===============================================================================
+
+use v5.32.1;       # Enables strictures
+use warnings;
+use Const::Fast;
+use List::Util     qw( min );
+use Regexp::Common qw( number );
+use Test::More;
+
+const my $USAGE => <<END;
+Usage:
+  perl $0 [<matrix> ...]
+  perl $0
+
+    [<matrix> ...]    A non-empty matrix of distinct unsigned integers
+                      e.g., "3 7 8" "9 11 13" "15 16 17"
+                      Note: the input matrix must be rectangular
+END
+
+#-------------------------------------------------------------------------------
+BEGIN
+#-------------------------------------------------------------------------------
+{
+    $| = 1;
+    print "\nChallenge 251, Task #2: Lucky Numbers (Perl)\n\n";
+}
+
+#===============================================================================
+MAIN:
+#===============================================================================
+{
+    if (scalar @ARGV == 0)
+    {
+        run_tests();
+    }
+    else
+    {
+        my $matrix = parse_matrix( \@ARGV );
+
+        print_matrix( 'Input:  $matrix = ', $matrix );
+
+        printf "Output: %d\n", find_lucky_number( $matrix );
+    }
+}
+
+#-------------------------------------------------------------------------------
+sub find_lucky_number
+#-------------------------------------------------------------------------------
+{
+    my ($matrix) = @_;
+
+    for my $row (@$matrix)
+    {
+        my $row_min = min @$row;                           # Row minimum
+
+        for my $col (0 .. $#$row)
+        {
+            if ($row->[ $col ] == $row_min)
+            {
+                my $col_max = 0;
+
+                for my $row (0 .. $#$matrix)               # Find column maximum
+                {
+                    my $elem = $matrix->[ $row ][ $col ];
+
+                    $col_max = $elem if $elem > $col_max;
+                }
+
+                return $row_min if $row_min == $col_max;
+            }
+        }
+    }
+
+    return -1;
+}
+
+#-------------------------------------------------------------------------------
+sub parse_matrix
+#-------------------------------------------------------------------------------
+{
+    my ($matrix_strs) = @_;
+    my  @matrix;
+    my  %dict;
+    my  $num_cols;
+
+    for my $row_str (@$matrix_strs)
+    {
+        my $row = fill_row( $row_str, \%dict );
+
+        push @matrix, $row;
+
+        if (defined $num_cols)
+        {
+            scalar @$row == $num_cols
+                or error( 'The matrix is not rectangular' );
+        }
+        else
+        {
+            ($num_cols = scalar @$row) > 0
+                or error( 'The first row is empty' );
+        }
+    }
+
+    return \@matrix;
+}
+
+#-------------------------------------------------------------------------------
+sub fill_row
+#-------------------------------------------------------------------------------
+{
+    my ($row_str, $dict) = @_;
+    my  @row;
+
+    for my $elem_str (split ' ', $row_str)        # split ' ' removes leading ws
+    {
+        $elem_str =~ / ^ $RE{num}{int} $ /x
+            or error( qq["$elem_str" is not a valid integer] );
+
+        my $elem = $elem_str + 0;                 # Normalize
+
+        $elem >= 0
+            or error( qq["$elem" is negative] );
+
+        ++$dict->{ $elem } == 1
+            or error( qq[Element "$elem" is repeated] );
+
+        push @row, $elem;
+    }
+
+    return \@row;
+}
+
+#-------------------------------------------------------------------------------
+sub print_matrix
+#-------------------------------------------------------------------------------
+{
+    my ($prefix, $matrix) = @_;
+    my  $tab   = ' ' x length $prefix;
+    my  @width = (1) x scalar @{ $matrix->[ 0 ] };
+
+    for my $row (@$matrix)
+    {
+        for my $i (0 .. $#$row)
+        {
+            my $w = length $row->[ $i ];
+
+            $width[ $i ] = $w if $w > $width[ $i ];
+        }
+    }
+
+    print "$prefix\[ ";
+
+    for my $i (0 .. $#$matrix)
+    {
+        my $row = $matrix->[ $i ];
+        my @row_str;
+
+        for my $j (0 .. $#$row)
+        {
+            push @row_str, sprintf '%*d', $width[ $j ], $row->[ $j ];
+        }
+
+        printf "%s\[%s]",  $i == 0 ? '' : $tab . '  ', join ', ', @row_str;
+        print  "\n" unless $i == $#$matrix;
+    }
+
+    print " ]\n";
+}
+
+#-------------------------------------------------------------------------------
+sub run_tests
+#-------------------------------------------------------------------------------
+{
+    print "Running the test suite\n";
+
+    while (my $line = <DATA>)
+    {
+        chomp $line;
+
+        my  ($test_name, $matrix_str, $expected) = split / \| /x, $line;
+
+        for ($test_name, $matrix_str, $expected)
+        {
+            s/ ^ \s+   //x;
+            s/   \s+ $ //x;
+        }
+
+        my @rows      = split / \; /x, $matrix_str;
+        my $matrix    = parse_matrix( \@rows );
+        my $lucky_num = find_lucky_number( $matrix );
+
+        is $lucky_num, $expected, $test_name;
+    }
+
+    done_testing;
+}
+
+#-------------------------------------------------------------------------------
+sub error
+#-------------------------------------------------------------------------------
+{
+    my ($message) = @_;
+
+    die "ERROR: $message\n$USAGE";
+}
+
+################################################################################
+
+__DATA__
+Example 1|   3 7 8;   9 11 13;    15 16 17|15
+Example 2|1 10 4 2; 9 3  8  7; 15 16 17 12|12
+Example 3|     7 8;      1  2;            | 7
+Singleton|       4;                       | 4
+None     |     1 3;      4  2;            |-1
diff --git a/challenge-251/athanasius/raku/ch-1.raku b/challenge-251/athanasius/raku/ch-1.raku
new file mode 100644
index 0000000000..45ac215f86
--- /dev/null
+++ b/challenge-251/athanasius/raku/ch-1.raku
@@ -0,0 +1,206 @@
+use v6d;
+
+################################################################################
+=begin comment
+
+Perl Weekly Challenge 251
+=========================
+
+TASK #1
+-------
+*Concatenation Value*
+
+Submitted by: Mohammad S Anwar
+
+You are given an array of integers, @ints.
+
+Write a script to find the concatenation value of the given array.
+
+The concatenation of two numbers is the number formed by concatenating their
+numerals.
+
+  For example, the concatenation of 10, 21 is 1021.
+  The concatenation value of @ints is initially equal to 0.
+  Perform this operation until @ints becomes empty:
+
+  If there exists more than one number in @ints, pick the first element
+  and last element in @ints respectively and add the value of their
+  concatenation to the concatenation value of @ints, then delete the
+  first and last element from @ints.
+
+  If one element exists, add its value to the concatenation value of
+  @ints, then delete it.
+
+Example 1
+
+  Input: @ints = (6, 12, 25, 1)
+  Output: 1286
+
+  1st operation: concatenation of 6 and 1 is 61
+  2nd operation: concaternation of 12 and 25 is 1225
+
+  Concatenation Value => 61 + 1225 => 1286
+
+Example 2
+
+  Input: @ints = (10, 7, 31, 5, 2, 2)
+  Output: 489
+
+  1st operation: concatenation of 10 and 2 is 102
+  2nd operation: concatenation of 7 and 2 is 72
+  3rd operation: concatenation of 31 and 5 is 315
+
+  Concatenation Value => 102 + 72 + 315 => 489
+
+Example 3
+
+  Input: @ints = (1, 2, 10)
+  Output: 112
+
+  1st operation: concatenation of 1 and 10 is 110
+  2nd operation: only element left is 2
+
+  Concatenation Value => 110 + 2 => 112
+
+=end comment
+################################################################################
+
+#--------------------------------------#
+# Copyright © 2024 PerlMonk Athanasius #
+#--------------------------------------#
+
+#===============================================================================
+=begin comment
+
+Assumption
+----------
+The input integers are unsigned (i.e., non-negative).
+
+Rationale: If the right hand side of a concatenation is a negative integer, then
+the result of the concatenation will not be an integer. (For example, "3" con-
+catenated with "-45" gives "3-45", which is not an integer.) The simplest way to
+avoid this possibility is to disallow negative numbers in the input.
+
+Interface
+---------
+If no command-line arguments are given, the test suite is run.
+
+=end comment
+#===============================================================================
+
+use Test;
+
+#-------------------------------------------------------------------------------
+BEGIN
+#-------------------------------------------------------------------------------
+{
+    "\nChallenge 251, Task #1: Concatenation Value (Raku)\n".put;
+}
+
+#===============================================================================
+multi sub MAIN
+(
+    #| A non-empty list of unsigned integers
+
+    *@ints where { .elems > 0 && .all ~~ UInt:D }
+)
+#===============================================================================
+{
+    "Input:  \@ints = (%s)\n".printf: @ints.join: ', ';
+
+    my UInt  $concat-value = find-concatenation-value( @ints );
+
+    "Output: $concat-value".put;
+}
+
+#===============================================================================
+multi sub MAIN()                                  # No input: run the test suite
+#===============================================================================
+{
+    run-tests();
+}
+
+#-------------------------------------------------------------------------------
+sub find-concatenation-value( List:D[UInt:D] $ints --> UInt:D )
+#-------------------------------------------------------------------------------
+{
+    my UInt @ints         = @$ints;
+    my UInt $concat-value = 0;
+
+    while @ints
+    {
+        # The prepended "+" operators normalize the integers; for example,
+        # "+234" becomes "234"
+
+        if @ints.elems == 1
+        {
+            $concat-value += +@ints.shift;
+        }
+        else
+        {
+            $concat-value += +@ints.shift ~ +@ints.pop;
+        }
+    }
+
+    return $concat-value;
+}
+
+#-------------------------------------------------------------------------------
+sub run-tests()
+#-------------------------------------------------------------------------------
+{
+    'Running the test suite'.put;
+
+    for test-data.lines -> Str $line
+    {
+        my Str ($test-name, $ints-str, $expected) = $line.split: / \| /;
+
+        for     $test-name, $ints-str, $expected
+        {
+            s/ ^ \s+   //;
+            s/   \s+ $ //;
+        }
+
+        my UInt @ints         = $ints-str.split( / \s+ / ).map: { .Int };
+        my UInt $concat-value = find-concatenation-value( @ints );
+
+        is $concat-value, $expected.Int, $test-name;
+    }
+
+    done-testing;
+}
+
+#-------------------------------------------------------------------------------
+sub error( Str:D $message )
+#-------------------------------------------------------------------------------
+{
+    "ERROR: $message".put;
+
+    USAGE();
+
+    exit 0;
+}
+
+#-------------------------------------------------------------------------------
+sub USAGE()
+#-------------------------------------------------------------------------------
+{
+    my Str $usage = $*USAGE;
+
+    $usage ~~ s:g/ ($*PROGRAM-NAME) /raku $0/;
+
+    $usage.put;
+}
+
+#-------------------------------------------------------------------------------
+sub test-data( --> Str:D )
+#-------------------------------------------------------------------------------
+{
+    return q:to/END/;
+        Example 1| 6 12 25 1    |1286
+        Example 2|10  7 31 5 2 2| 489
+        Example 3| 1  2 10      | 112
+        END
+}
+
+################################################################################
diff --git a/challenge-251/athanasius/raku/ch-2.raku b/challenge-251/athanasius/raku/ch-2.raku
new file mode 100644
index 0000000000..4fd942d0a1
--- /dev/null
+++ b/challenge-251/athanasius/raku/ch-2.raku
@@ -0,0 +1,313 @@
+use v6d;
+
+################################################################################
+=begin comment
+
+Perl Weekly Challenge 251
+=========================
+
+TASK #2
+-------
+*Lucky Numbers*
+
+Submitted by: Mohammad S Anwar
+
+You are given a m x n matrix of distinct numbers.
+
+Write a script to return the lucky number, if there is one, or -1 if not.
+
+  A lucky number is an element of the matrix such that it is
+  the minimum element in its row and maximum in its column.
+
+Example 1
+
+  Input: $matrix = [ [ 3,  7,  8],
+                     [ 9, 11, 13],
+                     [15, 16, 17] ];
+  Output: 15
+
+  15 is the only lucky number since it is the minimum in its row
+  and the maximum in its column.
+
+Example 2
+
+  Input: $matrix = [ [ 1, 10,  4,  2],
+                     [ 9,  3,  8,  7],
+                     [15, 16, 17, 12] ];
+  Output: 12
+
+Example 3
+
+  Input: $matrix = [ [7, 8],
+                     [1, 2] ];
+  Output: 7
+
+=end comment
+################################################################################
+
+#--------------------------------------#
+# Copyright © 2024 PerlMonk Athanasius #
+#--------------------------------------#
+
+#===============================================================================
+=begin comment
+
+Interface
+---------
+If no command-line arguments are given, the test suite is run.
+
+Assumptions
+-----------
+Since -1 is returned on failure, elements of the input matrix are limited to
+non-negative numbers. For convenience, they are in addition limited to integers.
+
+Algorithm
+---------
+This is a simple search for a lucky number: if one is found, it is immediately
+returned, otherwise after the search has completed -1 is returned.
+
+In fact, there can only ever be one lucky number for a given matrix. Proof (by
+contradiction):
+
+1. Let element x = matrix(i, j) be a lucky number. Can there be another lucky
+   number in the same matrix?
+
+2. Assume there is a lucky number y = matrix(k, l) with k ≠ i and l ≠ j.
+
+3. Let w = matrix(i, l). Since x is the smallest element in row i, w > x.
+   And since y is the largest element in column l, y > w. So, y > w > x, and by
+   transitivity, y > x (a).
+
+4. Let z = matrix(k, j). Since x is the largest element in column j, z < x.
+   And since y is the smallest element in row k, y < z. So, y < z < x, and by
+   transitivity, y < x (b).
+
+5. Relations (a) and (b) are mutually contradictory, therefore the assumption
+   made in step 2 must be false. QED.
+
+Note
+----
+This solution incorporates or adapts code used in the solution of Task 2 for
+Challenge 248.
+
+=end comment
+#===============================================================================
+
+use Test;
+
+#-------------------------------------------------------------------------------
+BEGIN
+#-------------------------------------------------------------------------------
+{
+    "\nChallenge 251, Task #2: Lucky Numbers (Raku)\n".put;
+}
+
+#===============================================================================
+multi sub MAIN
+(
+    #| A non-empty matrix of distinct unsigned integers
+    #  e.g., "3 7 8" "9 11 13" "15 16 17"
+    #  Note: the input matrix must be rectangular
+
+    *@matrix where { .elems > 0 && .all ~~ Str:D }
+)
+#===============================================================================
+{
+    my Array[Array[UInt]] $matrix = parse-matrix( @matrix );
+
+    print-matrix( 'Input:  $matrix = ', $matrix );
+
+    "Output: %d\n".printf: find-lucky-number( $matrix );
+}
+
+#===============================================================================
+multi sub MAIN()                                  # No input: run the test suite
+#===============================================================================
+{
+    run-tests();
+}
+
+#-------------------------------------------------------------------------------
+sub find-lucky-number( List:D[List:D[UInt:D]] $matrix --> Int:D )
+#-------------------------------------------------------------------------------
+{
+    for @$matrix -> Array[UInt] $row
+    {
+        my UInt $row-min = $row.min;                       # Row minimum
+
+        for 0 .. $row.end -> UInt $col
+        {
+            if $row[ $col ] == $row-min
+            {
+                my UInt $col-max = 0;
+
+                for 0 .. $matrix.end -> UInt $row          # Find column maximum
+                {
+                    my UInt $elem = $matrix[ $row; $col ];
+
+                    $col-max = $elem if $elem > $col-max;
+                }
+
+                return $row-min if $row-min == $col-max;
+            }
+        }
+    }
+
+    return -1;
+}
+
+#-------------------------------------------------------------------------------
+sub parse-matrix
+(
+    List:D[Str:D] $matrix-strs where { .elems > 0 }
+--> List:D[List:D[UInt:D]]
+)
+#-------------------------------------------------------------------------------
+{
+    my Array[UInt] @matrix;
+    my UInt        %dict{UInt};
+    my UInt        $num-cols;
+
+    for @$matrix-strs -> Str $row-str
+    {
+        my UInt @row = fill-row( $row-str, %dict );
+
+        @matrix.push: @row;
+
+        if $num-cols.defined
+        {
+            @row.elems == $num-cols
+                or error( 'The matrix is not rectangular' );
+        }
+        else
+        {
+            ($num-cols = @row.elems) > 0
+                or error( 'The first row is empty' );
+        }
+    }
+
+    return @matrix;
+}
+
+#-------------------------------------------------------------------------------
+sub fill-row( Str:D $row-str, Hash:D[UInt:D, UInt:D] $dict --> List:D[UInt:D] )
+#-------------------------------------------------------------------------------
+{
+    my UInt @row;
+
+    for $row-str.split( / \s+ /, :skip-empty ) -> Str $elem-str
+    {
+        +$elem-str ~~ UInt:D
+            or error( qq["$elem-str" is not a valid unsigned integer] );
+
+        my UInt $elem = +$elem-str;         # Normalize
+
+        ++$dict{ $elem } == 1
+            or error( qq[Element "$elem" is repeated] );
+
+        @row.push: $elem;
+    }
+
+    return @row;
+}
+
+#-------------------------------------------------------------------------------
+sub print-matrix( Str:D $prefix, List:D[List:D[Int:D]] $matrix )
+#-------------------------------------------------------------------------------
+{
+    my Str  $tab   = ' ' x $prefix.chars;
+    my UInt @width = 1 xx $matrix[ 0 ].elems;
+
+    for @$matrix -> Int @row
+    {
+        for 0 .. @row.end -> UInt $i
+        {
+            my UInt $w = @row[ $i ].chars;
+
+            @width[ $i ] = $w if $w > @width[ $i ];
+        }
+    }
+
+    "$prefix\[ ".print;
+
+    for 0 .. $matrix.end -> UInt $i
+    {
+        my Array[UInt] $row = $matrix[ $i ];
+        my Str         @row-str;
+
+        for 0 .. $row.end -> UInt $j
+        {
+            @row-str.push: '%*d'.sprintf: @width[ $j ], $row[ $j ];
+        }
+
+        "%s\[%s]".printf: $i == 0 ?? '' !! $tab ~ '  ', @row-str.join: ', ';
+
+        put() unless $i == $matrix.end;
+    }
+
+    ' ]'.put;
+}
+
+#-------------------------------------------------------------------------------
+sub run-tests()
+#-------------------------------------------------------------------------------
+{
+    'Running the test suite'.put;
+
+    for test-data.lines -> Str $line
+    {
+        my Str ($test-name, $matrix-str, $expected) = $line.split: / \| /;
+
+        for     $test-name, $matrix-str, $expected
+        {
+            s/ ^ \s+   //;
+            s/   \s+ $ //;
+        }
+
+        my Array[Array[UInt]] $matrix =
+                parse-matrix( $matrix-str.split( / \; /, :skip-empty ).list );
+
+        my Int $lucky-num = find-lucky-number( $matrix );
+
+        is $lucky-num, $expected.Int, $test-name;
+    }
+
+    done-testing;
+}
+
+#-------------------------------------------------------------------------------
+sub error( Str:D $message )
+#-------------------------------------------------------------------------------
+{
+    "ERROR: $message".put;
+
+    USAGE();
+
+    exit 0;
+}
+
+#-------------------------------------------------------------------------------
+sub USAGE()
+#-------------------------------------------------------------------------------
+{
+    my Str $usage = $*USAGE;
+
+    $usage ~~ s:g/ ($*PROGRAM-NAME) /raku $0/;
+
+    $usage.put;
+}
+
+#-------------------------------------------------------------------------------
+sub test-data( --> Str:D )
+#-------------------------------------------------------------------------------
+{
+    return q:to/END/;
+        Example 1|   3 7 8;   9 11 13;    15 16 17|15
+        Example 2|1 10 4 2; 9 3  8  7; 15 16 17 12|12
+        Example 3|     7 8;      1  2;            | 7
+        Singleton|       4;                       | 4
+        None     |     1 3;      4  2;            |-1
+        END
+}
+
+################################################################################