- Added solutions in Perl, Raku and Swift.

23 files changed, 3060 insertions, 1901 deletions

diff --git a/challenge-075/mohammad-anwar/perl/ch-1.pl b/challenge-075/mohammad-anwar/perl/ch-1.pl
new file mode 100755
index 0000000000..7749fa9364
--- /dev/null
+++ b/challenge-075/mohammad-anwar/perl/ch-1.pl
@@ -0,0 +1,64 @@
+#!/usr/bin/perl
+
+#
+# Perl Weekly Challenge - 075
+#
+# Task #1: Coins Sum
+#
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-075
+#
+
+use strict;
+use warnings;
+
+my $COINS = $ARGV[0] || "1, 2, 4";
+my $SUM   = $ARGV[1] || 6;
+
+print "Possible ways to achieve the target: ",
+      coins_sum(prepare($COINS), $SUM), "\n";
+
+#
+#
+# METHODS
+
+sub coins_sum {
+    my ($coins, $sum) = @_;
+
+    my $size = $#$coins;
+    return 0 if ($size == -1 || $sum <= 0);
+
+    my $matrix;
+
+    # Sum of 0 can be achieved in one possible way.
+    $matrix->[$_][0] = 1 for (0 .. $size+1);
+
+    foreach my $i (0 .. $size) {
+
+        foreach my $j (1 .. $sum) {
+
+            my $include_current = 0;
+            my $exclude_current = 0;
+
+            if ($coins->[$i] <= $j) {
+                $include_current = $matrix->[$i][$j - $coins->[$i]];
+            }
+
+            if ($i > 0) {
+                $exclude_current = $matrix->[$i - 1][$j];
+            }
+
+            $matrix->[$i][$j] = $include_current + $exclude_current;
+        }
+    }
+
+    return $matrix->[$size][$sum];
+}
+
+sub prepare {
+    my ($coins) = @_;
+
+    if (defined $coins) {
+        $coins =~ s/\s//g;
+        return [ split /\,/, $coins ];
+    }
+}
diff --git a/challenge-075/mohammad-anwar/perl/ch-1.t b/challenge-075/mohammad-anwar/perl/ch-1.t
new file mode 100755
index 0000000000..c2d32443b5
--- /dev/null
+++ b/challenge-075/mohammad-anwar/perl/ch-1.t
@@ -0,0 +1,67 @@
+#!/usr/bin/perl
+
+#
+# Perl Weekly Challenge - 075
+#
+# Task #1: Coins Sum
+#
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-075
+#
+
+use strict;
+use warnings;
+use Test::More;
+
+is coins_sum(prepare("1, 2"),        5), 3;
+is coins_sum(prepare("1, 2, 3"),     5), 5;
+is coins_sum(prepare("1, 2, 4"),     6), 6;
+is coins_sum(prepare("25, 10, 5"),  30), 5;
+is coins_sum(prepare("9, 6, 5, 1"), 11), 6;
+
+done_testing;
+
+#
+#
+# METHODS
+
+sub coins_sum {
+    my ($coins, $sum) = @_;
+
+    my $size = $#$coins;
+    return 0 if ($size == -1 || $sum <= 0);
+
+    my $matrix;
+
+    # Sum of 0 can be achieved in one possible way.
+    $matrix->[$_][0] = 1 for (0 .. $size+1);
+
+    foreach my $i (0 .. $size) {
+
+        foreach my $j (1 .. $sum) {
+
+            my $include_current = 0;
+            my $exclude_current = 0;
+
+            if ($coins->[$i] <= $j) {
+                $include_current = $matrix->[$i][$j - $coins->[$i]];
+            }
+
+            if ($i > 0) {
+                $exclude_current = $matrix->[$i - 1][$j];
+            }
+
+            $matrix->[$i][$j] = $include_current + $exclude_current;
+        }
+    }
+
+    return $matrix->[$size][$sum];
+}
+
+sub prepare {
+    my ($coins) = @_;
+
+    if (defined $coins) {
+        $coins =~ s/\s//g;
+        return [ split /\,/, $coins ];
+    }
+}
diff --git a/challenge-075/mohammad-anwar/perl/ch-2.pl b/challenge-075/mohammad-anwar/perl/ch-2.pl
new file mode 100755
index 0000000000..7749fa9364
--- /dev/null
+++ b/challenge-075/mohammad-anwar/perl/ch-2.pl
@@ -0,0 +1,64 @@
+#!/usr/bin/perl
+
+#
+# Perl Weekly Challenge - 075
+#
+# Task #1: Coins Sum
+#
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-075
+#
+
+use strict;
+use warnings;
+
+my $COINS = $ARGV[0] || "1, 2, 4";
+my $SUM   = $ARGV[1] || 6;
+
+print "Possible ways to achieve the target: ",
+      coins_sum(prepare($COINS), $SUM), "\n";
+
+#
+#
+# METHODS
+
+sub coins_sum {
+    my ($coins, $sum) = @_;
+
+    my $size = $#$coins;
+    return 0 if ($size == -1 || $sum <= 0);
+
+    my $matrix;
+
+    # Sum of 0 can be achieved in one possible way.
+    $matrix->[$_][0] = 1 for (0 .. $size+1);
+
+    foreach my $i (0 .. $size) {
+
+        foreach my $j (1 .. $sum) {
+
+            my $include_current = 0;
+            my $exclude_current = 0;
+
+            if ($coins->[$i] <= $j) {
+                $include_current = $matrix->[$i][$j - $coins->[$i]];
+            }
+
+            if ($i > 0) {
+                $exclude_current = $matrix->[$i - 1][$j];
+            }
+
+            $matrix->[$i][$j] = $include_current + $exclude_current;
+        }
+    }
+
+    return $matrix->[$size][$sum];
+}
+
+sub prepare {
+    my ($coins) = @_;
+
+    if (defined $coins) {
+        $coins =~ s/\s//g;
+        return [ split /\,/, $coins ];
+    }
+}
diff --git a/challenge-075/mohammad-anwar/perl/ch-2.t b/challenge-075/mohammad-anwar/perl/ch-2.t
new file mode 100755
index 0000000000..c2d32443b5
--- /dev/null
+++ b/challenge-075/mohammad-anwar/perl/ch-2.t
@@ -0,0 +1,67 @@
+#!/usr/bin/perl
+
+#
+# Perl Weekly Challenge - 075
+#
+# Task #1: Coins Sum
+#
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-075
+#
+
+use strict;
+use warnings;
+use Test::More;
+
+is coins_sum(prepare("1, 2"),        5), 3;
+is coins_sum(prepare("1, 2, 3"),     5), 5;
+is coins_sum(prepare("1, 2, 4"),     6), 6;
+is coins_sum(prepare("25, 10, 5"),  30), 5;
+is coins_sum(prepare("9, 6, 5, 1"), 11), 6;
+
+done_testing;
+
+#
+#
+# METHODS
+
+sub coins_sum {
+    my ($coins, $sum) = @_;
+
+    my $size = $#$coins;
+    return 0 if ($size == -1 || $sum <= 0);
+
+    my $matrix;
+
+    # Sum of 0 can be achieved in one possible way.
+    $matrix->[$_][0] = 1 for (0 .. $size+1);
+
+    foreach my $i (0 .. $size) {
+
+        foreach my $j (1 .. $sum) {
+
+            my $include_current = 0;
+            my $exclude_current = 0;
+
+            if ($coins->[$i] <= $j) {
+                $include_current = $matrix->[$i][$j - $coins->[$i]];
+            }
+
+            if ($i > 0) {
+                $exclude_current = $matrix->[$i - 1][$j];
+            }
+
+            $matrix->[$i][$j] = $include_current + $exclude_current;
+        }
+    }
+
+    return $matrix->[$size][$sum];
+}
+
+sub prepare {
+    my ($coins) = @_;
+
+    if (defined $coins) {
+        $coins =~ s/\s//g;
+        return [ split /\,/, $coins ];
+    }
+}
diff --git a/challenge-075/mohammad-anwar/raku/ch-1.raku b/challenge-075/mohammad-anwar/raku/ch-1.raku
new file mode 100755
index 0000000000..f6bade8c9f
--- /dev/null
+++ b/challenge-075/mohammad-anwar/raku/ch-1.raku
@@ -0,0 +1,55 @@
+#!/usr/bin/env raku
+
+#
+# Perl Weekly Challenge - 075
+#
+# Task #1: Coins Sum
+#
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-075
+#
+
+use v6.d;
+
+sub MAIN(Str :$COINS = "1, 2, 4", Int :$SUM = 6) {
+    say "Possible ways to achieve the target: " ~
+        coins-sum($COINS, $SUM);
+}
+
+sub coins-sum(Str $coins is copy, Int $sum) returns Int {
+
+    die "ERROR: Invalid coins [$coins].\n"
+        unless $coins ~~ /^[\s?\-?\d\,?\s?]+$/;
+
+    say "Coins: $coins";
+    $coins ~~ s:g/\s//;
+    my $_coins = [ $coins.split(',').map({ .Int }) ];
+
+    my $size = $_coins.elems;
+    return 0 if ($size == 0 || $sum <= 0);
+
+    my $matrix;
+
+    # Sum of 0 can be achieved in one possible way.
+    $matrix.[$_][0] = 1 for (0 .. $size-1);
+
+    for 0 .. $size-1 -> $i {
+
+        for 1 .. $sum -> $j {
+
+            my Int $include-current = 0;
+            my Int $exclude-current = 0;
+
+            if $_coins.[$i] <= $j {
+                $include-current = $matrix.[$i][$j - $_coins.[$i]];
+            }
+
+            if $i > 0 {
+                $exclude-current = $matrix.[$i - 1][$j];
+            }
+
+            $matrix.[$i][$j] = $include-current + $exclude-current;
+        }
+    }
+
+    return $matrix.[$size-1][$sum];
+}
diff --git a/challenge-075/mohammad-anwar/raku/ch-1.t b/challenge-075/mohammad-anwar/raku/ch-1.t
new file mode 100755
index 0000000000..e1a0e5b656
--- /dev/null
+++ b/challenge-075/mohammad-anwar/raku/ch-1.t
@@ -0,0 +1,57 @@
+#!/usr/bin/env raku
+
+#
+# Perl Weekly Challenge - 075
+#
+# Task #1: Coins Sum
+#
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-075
+#
+
+use Test;
+
+is coins-sum("1, 2", 5), 3,        "Coins=[1, 2]       Sum=5";
+is coins-sum("1, 2, 3", 5), 5,     "Coins=[1, 2, 3]    Sum=5";
+is coins-sum("1, 2, 4", 6), 6,     "Coins=[1, 2, 4]    Sum=6";
+is coins-sum("25, 10, 5", 30), 5,  "Coins=[25, 10, 5]  Sum=30";
+is coins-sum("9, 6, 5, 1", 11), 6, "Coins=[9, 6, 5, 1] Sum=6";
+
+done-testing;
+
+sub coins-sum(Str $coins is copy, Int $sum) returns Int {
+
+    die "ERROR: Invalid coins [$coins].\n"
+        unless $coins ~~ /^[\s?\-?\d\,?\s?]+$/;
+
+    $coins ~~ s:g/\s//;
+    my $_coins = [ $coins.split(',').map({ .Int }) ];
+
+    my $size = $_coins.elems;
+    return 0 if ($size == 0 || $sum <= 0);
+
+    my $matrix;
+
+    # Sum of 0 can be achieved in one possible way.
+    $matrix.[$_][0] = 1 for (0 .. $size-1);
+
+    for 0 .. $size-1 -> $i {
+
+        for 1 .. $sum -> $j {
+
+            my Int $include-current = 0;
+            my Int $exclude-current = 0;
+
+            if $_coins.[$i] <= $j {
+                $include-current = $matrix.[$i][$j - $_coins.[$i]];
+            }
+
+            if $i > 0 {
+                $exclude-current = $matrix.[$i - 1][$j];
+            }
+
+            $matrix.[$i][$j] = $include-current + $exclude-current;
+        }
+    }
+
+    return $matrix.[$size-1][$sum];
+}
diff --git a/challenge-075/mohammad-anwar/raku/ch-2.raku b/challenge-075/mohammad-anwar/raku/ch-2.raku
new file mode 100755
index 0000000000..024006d590
--- /dev/null
+++ b/challenge-075/mohammad-anwar/raku/ch-2.raku
@@ -0,0 +1,204 @@
+#!/usr/bin/env raku
+
+#
+# Perl Weekly Challenge - 075
+#
+# Task #2: Largest Rectangle Histogram
+#
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-075
+#
+
+use v6.d;
+
+sub MAIN(Str :$LIST = "2, 1, 4, 5, 3, 7") {
+    my $list = prepare($LIST);
+    chart($list).say;
+    say "Largest Rectangle Histogram: " ~
+        largest-rectangle-histogram($list);
+}
+
+#
+#
+# METHODS
+
+sub largest-rectangle-histogram($list where .all ~~ Int) returns Int {
+
+    my Int $i   = 0;
+    my Int $max = 0;
+
+    for 0 .. $list.elems-1 -> $i {
+
+        my (Int $left, Int $right) = (0, 0);
+        $left  = go-left($i, $list)  if $i > 0;
+        $right = go-right($i, $list) if $i < $list.elems;
+
+        my $heights = $list.[$i - $left .. $i + $right];
+        my $size    = $heights.min * $heights.elems;
+
+        $max = $size if $size > $max;
+    }
+
+    return $max;
+}
+
+sub go-left(Int $i is copy, $list where .all ~~ Int) returns Int {
+
+    my $c = $list.[$i];
+    my $j = 0;
+    while $i > 0 {
+        $i = $i - 1;
+        last if $list.[$i] < $c;
+        $j = $j + 1;
+    }
+
+    return $j;
+}
+
+sub go-right(Int $i is copy, $list where .all ~~ Int) returns Int {
+
+    my $c = $list.[$i];
+    my $j = 0;
+    while $i < $list.elems-1 {
+        $i += 1;
+        last if $list.[$i] < $c;
+        $j += 1;
+    }
+
+    return $j;
+}
+
+sub chart($list where .all ~~ Int) {
+
+    my $max   = $list.max;
+    my $chart = [];
+    my $row   = 1;
+    for 1 .. $max -> $n {
+        my Str $data = "";
+        for 0 .. $list.elems-1 -> $i {
+            if $row <= $list.[$i] {
+                $data ~= " #";
+            }
+            else {
+                $data ~= "  ";
+            }
+        }
+
+        $row += 1;
+
+        $chart.push: sprintf("%d%s", $n, $data);
+    }
+
+    my (Str $histogram, Str $line, Str $size) = ("", "", "  ");
+    $histogram = $chart.reverse.join("\n");
+    $line ~= "_ " for 0 .. $list.elems;
+    $size ~= $list.join(" ");
+
+    return ($histogram, $line, $size).join("\n");
+}
+
+sub prepare(Str $list is copy) {
+
+    return unless $list.defined;
+
+    die "ERROR: Invalid list [$list].\n"
+        unless $list ~~ /^[\s?\-?\d\,?\s?]+$/;
+
+    $list ~~ s:g/\s//;
+    return [ $list.split(',').map({ .Int }) ];
+}
+
+=finish
+
+my $list = prepare($L);
+print chart($list), "\n\n";
+print "Largest Rectangle Histogram: ", largest_rectangle_histogram($list), "\n";
+
+#
+#
+# METHODS
+
+sub largest_rectangle_histogram {
+    my ($list) = @_;
+
+    my $i   = 0;
+    my $max = 0;
+    foreach my $n (@$list) {
+
+        my ($left, $right) = (0, 0);
+        $left  = go_left($i, $list)  if ($i > 0);
+        $right = go_right($i, $list) if ($i <= $#$list);
+
+        my @heights = (@$list)[$i - $left .. $i + $right];
+        my $size    = min(@heights) * @heights;
+        $max = $size if ($size > $max);
+
+        $i++;
+    }
+
+    return $max;
+}
+
+sub go_left {
+    my ($i, $list) = @_;
+
+    my $c = $list->[$i];
+    my $j = 0;
+    while ($i > 0) {
+        $i--;
+        last if ($list->[$i] < $c);
+        $j++;
+    }
+
+    return $j;
+}
+
+sub go_right {
+    my ($i, $list) = @_;
+
+    my $c = $list->[$i];
+    my $j = 0;
+    while ($i < $#$list) {
+        $i++;
+        last if ($list->[$i] < $c);
+        $j++;
+    }
+
+    return $j;
+}
+
+sub chart {
+    my ($list) = @_;
+
+    my $max   = max(@$list);
+    my $chart = [];
+    my $row   = 1;
+    foreach (1..$max) {
+        my $data = "";
+        foreach my $i (0..$#$list) {
+            if ($row <= $list->[$i]) {
+                $data .= " #";
+            }
+            else {
+                $data .= "  ";
+            }
+        }
+        $row++;
+        push @$chart, sprintf("%d%s", $_, $data);
+    }
+
+    my ($histogram, $line, $size) = ("", "", "  ");
+    $histogram = join "\n", (reverse @$chart);
+    $line .= "_ " for (0..$#$list + 1);
+    $size .= join " ", @$list;
+
+    return join "\n", $histogram, $line, $size;
+}
+
+sub prepare {
+    my ($list) = @_;
+
+    if (defined $list) {
+        $list =~ s/\s//g;
+        return [ split /\,/, $list ];
+    }
+}
diff --git a/challenge-075/mohammad-anwar/raku/ch-2.t b/challenge-075/mohammad-anwar/raku/ch-2.t
new file mode 100755
index 0000000000..b0e420faa3
--- /dev/null
+++ b/challenge-075/mohammad-anwar/raku/ch-2.t
@@ -0,0 +1,202 @@
+#!/usr/bin/env raku
+
+#
+# Perl Weekly Challenge - 075
+#
+# Task #2: Largest Rectangle Histogram
+#
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-075
+#
+
+use Test;
+
+is largest-rectangle-histogram(prepare("2, 1, 4, 5, 3, 7")), 12, "example 1";
+is largest-rectangle-histogram(prepare("3, 2, 3, 5, 7, 5")), 15, "example 2";
+
+done-testing;
+
+#
+#
+# METHODS
+
+sub largest-rectangle-histogram($list where .all ~~ Int) returns Int {
+
+    my Int $i   = 0;
+    my Int $max = 0;
+
+    for 0 .. $list.elems-1 -> $i {
+
+        my (Int $left, Int $right) = (0, 0);
+        $left  = go-left($i, $list)  if $i > 0;
+        $right = go-right($i, $list) if $i < $list.elems;
+
+        my $heights = $list.[$i - $left .. $i + $right];
+        my $size    = $heights.min * $heights.elems;
+
+        $max = $size if $size > $max;
+    }
+
+    return $max;
+}
+
+sub go-left(Int $i is copy, $list where .all ~~ Int) returns Int {
+
+    my $c = $list.[$i];
+    my $j = 0;
+    while $i > 0 {
+        $i = $i - 1;
+        last if $list.[$i] < $c;
+        $j = $j + 1;
+    }
+
+    return $j;
+}
+
+sub go-right(Int $i is copy, $list where .all ~~ Int) returns Int {
+
+    my $c = $list.[$i];
+    my $j = 0;
+    while $i < $list.elems-1 {
+        $i += 1;
+        last if $list.[$i] < $c;
+        $j += 1;
+    }
+
+    return $j;
+}
+
+sub chart($list where .all ~~ Int) {
+
+    my $max   = $list.max;
+    my $chart = [];
+    my $row   = 1;
+    for 1 .. $max -> $n {
+        my Str $data = "";
+        for 0 .. $list.elems-1 -> $i {
+            if $row <= $list.[$i] {
+                $data ~= " #";
+            }
+            else {
+                $data ~= "  ";
+            }
+        }
+
+        $row += 1;
+
+        $chart.push: sprintf("%d%s", $n, $data);
+    }
+
+    my (Str $histogram, Str $line, Str $size) = ("", "", "  ");
+    $histogram = $chart.reverse.join("\n");
+    $line ~= "_ " for 0 .. $list.elems;
+    $size ~= $list.join(" ");
+
+    return ($histogram, $line, $size).join("\n");
+}
+
+sub prepare(Str $list is copy) {
+
+    return unless $list.defined;
+
+    die "ERROR: Invalid list [$list].\n"
+        unless $list ~~ /^[\s?\-?\d\,?\s?]+$/;
+
+    $list ~~ s:g/\s//;
+    return [ $list.split(',').map({ .Int }) ];
+}
+
+=finish
+
+my $list = prepare($L);
+print chart($list), "\n\n";
+print "Largest Rectangle Histogram: ", largest_rectangle_histogram($list), "\n";
+
+#
+#
+# METHODS
+
+sub largest_rectangle_histogram {
+    my ($list) = @_;
+
+    my $i   = 0;
+    my $max = 0;
+    foreach my $n (@$list) {
+
+        my ($left, $right) = (0, 0);
+        $left  = go_left($i, $list)  if ($i > 0);
+        $right = go_right($i, $list) if ($i <= $#$list);
+
+        my @heights = (@$list)[$i - $left .. $i + $right];
+        my $size    = min(@heights) * @heights;
+        $max = $size if ($size > $max);
+
+        $i++;
+    }
+
+    return $max;
+}
+
+sub go_left {
+    my ($i, $list) = @_;
+
+    my $c = $list->[$i];
+    my $j = 0;
+    while ($i > 0) {
+        $i--;
+        last if ($list->[$i] < $c);
+        $j++;
+    }
+
+    return $j;
+}
+
+sub go_right {
+    my ($i, $list) = @_;
+
+    my $c = $list->[$i];
+    my $j = 0;
+    while ($i < $#$list) {
+        $i++;
+        last if ($list->[$i] < $c);
+        $j++;
+    }
+
+    return $j;
+}
+
+sub chart {
+    my ($list) = @_;
+
+    my $max   = max(@$list);
+    my $chart = [];
+    my $row   = 1;
+    foreach (1..$max) {
+        my $data = "";
+        foreach my $i (0..$#$list) {
+            if ($row <= $list->[$i]) {
+                $data .= " #";
+            }
+            else {
+                $data .= "  ";
+            }
+        }
+        $row++;
+        push @$chart, sprintf("%d%s", $_, $data);
+    }
+
+    my ($histogram, $line, $size) = ("", "", "  ");
+    $histogram = join "\n", (reverse @$chart);
+    $line .= "_ " for (0..$#$list + 1);
+    $size .= join " ", @$list;
+
+    return join "\n", $histogram, $line, $size;
+}
+
+sub prepare {
+    my ($list) = @_;
+
+    if (defined $list) {
+        $list =~ s/\s//g;
+        return [ split /\,/, $list ];
+    }
+}
diff --git a/challenge-075/mohammad-anwar/swift/ch-1.swift b/challenge-075/mohammad-anwar/swift/ch-1.swift
new file mode 100755
index 0000000000..016bfba8bf
--- /dev/null
+++ b/challenge-075/mohammad-anwar/swift/ch-1.swift
@@ -0,0 +1,110 @@
+import Foundation
+
+/*
+
+Perl Weekly Challenge - 075
+
+Task #1: Coins Sum
+
+https://perlweeklychallenge.org/blog/perl-weekly-challenge-075
+
+*/
+
+enum ParamError: Error {
+    case missingList
+    case missingSum
+    case invalidList
+    case invalidSum
+}
+
+do {
+    let paramCount:Int = Int(CommandLine.argc)
+
+    if paramCount <= 1 {
+        throw ParamError.missingList
+    }
+
+    let list:String = CommandLine.arguments[1]
+
+    if isValidList(list) {
+
+        let sum:Int = Int(CommandLine.arguments[2])!
+        if sum > 0 {
+            let coins = list.components(separatedBy: ", ")
+            let size:Int = coins.count - 1
+
+            if size >= 1 {
+
+                var matrix = [[Int]]()
+
+                // Sum of 0 can be achieved in one possible way.
+                for _ in 0...size {
+                    var row = [Int]()
+                    row.append(1)
+                    matrix.append(row)
+                }
+
+                for i in 0...size {
+
+                    for j in 1...sum {
+
+                        var includeCurrent:Int = 0
+                        var excludeCurrent:Int = 0
+                        let currentCoin:Int    = Int(coins[i])!
+
+                        if currentCoin <= j {
+                            includeCurrent = matrix[i][j - currentCoin]
+                        }
+
+                        if i > 0 {
+                            excludeCurrent = matrix[i - 1][j]
+                        }
+
+                        matrix[i].append(includeCurrent + excludeCurrent)
+                    }
+                }
+
+                print(matrix[size][sum])
+            }
+        }
+        else {
+            throw ParamError.invalidSum
+        }
+    }
+    else {
+        throw ParamError.invalidList
+    }
+}
+catch ParamError.missingList {
+    print("Missing list.")
+}
+catch ParamError.missingSum {
+    print("Missinng sum.")
+}
+catch ParamError.invalidList {
+    print("Invalid list.")
+}
+catch ParamError.invalidSum {
+    print("Invalid Sum.")
+}
+catch let error {
+    print(error)
+}
+
+//
+//
+// Function
+
+func isValidList(_ list:String) -> Bool {
+
+    let pattern = "^[\\-?\\d\\,?\\s?]+$"
+    let regex   = try! NSRegularExpression(pattern: pattern)
+    let range   = NSRange(location: 0, length: list.utf16.count)
+
+    if regex.firstMatch(in: list, options: [], range: range) != nil {
+        return true
+    }
+    else {
+        return false
+    }
+}
diff --git a/challenge-075/mohammad-anwar/swift/ch-2.swift b/challenge-075/mohammad-anwar/swift/ch-2.swift
new file mode 100755
index 0000000000..cc38ea1a7c
--- /dev/null
+++ b/challenge-075/mohammad-anwar/swift/ch-2.swift
@@ -0,0 +1,179 @@
+import Foundation
+
+/*
+
+Perl Weekly Challenge - 075
+
+Task #2: Largest Rectangle Histogram
+
+https://perlweeklychallenge.org/blog/perl-weekly-challenge-075
+
+*/
+
+enum ParamError: Error {
+    case missingList
+    case invalidList
+}
+
+do {
+    let paramCount:Int = Int(CommandLine.argc)
+
+    if paramCount <= 1 {
+        throw ParamError.missingList
+    }
+
+    let list:String = CommandLine.arguments[1]
+
+    if isValidList(list) {
+        let heights:[Int] = prepare(list)
+
+        print(chart(heights))
+        print("\nLargest Rectangle Histogram: " +
+              String(largestRectangleHistogram(heights)))
+    }
+    else {
+        throw ParamError.invalidList
+    }
+}
+catch ParamError.missingList {
+    print("Missing list.")
+}
+catch ParamError.invalidList {
+    print("Invalid list.")
+}
+catch let error {
+    print(error)
+}
+
+//
+//
+// Functions
+
+func isValidList(_ list:String) -> Bool {
+
+    let pattern = "^[\\-?\\d\\,?\\s?]+$"
+    let regex   = try! NSRegularExpression(pattern: pattern)
+    let range   = NSRange(location: 0, length: list.utf16.count)
+
+    if regex.firstMatch(in: list, options: [], range: range) != nil {
+        return true
+    }
+    else {
+        return false
+    }
+}
+
+func largestRectangleHistogram(_ heights:[Int]) -> Int {
+
+    var max:Int = 0
+
+    for i in 0...heights.count-1 {
+
+        var left:Int  = 0
+        var right:Int = 0
+
+        if i > 0 {
+            left = goLeft(i, heights)
+        }
+
+        if i <= heights.count-1 {
+            right = goRight(i, heights)
+        }
+
+        let _heights:[Int] = Array(heights[i - left ... i + right])
+        let size:Int       = _heights.min()! * _heights.count
+
+        if size > max {
+            max = size
+        }
+
+    }
+
+    return max
+}
+
+func goLeft(_ i:Int, _ heights:[Int]) -> Int {
+
+    let c:Int  = heights[i]
+    var j:Int  = 0
+    var _i:Int = i
+    while _i > 0 {
+        _i -= 1
+        if heights[_i] < c {
+            break
+        }
+        j += 1
+    }
+
+    return j
+}
+
+func goRight(_ i:Int, _ heights:[Int]) -> Int {
+
+    let c:Int  = heights[i]
+    var j:Int  = 0
+    var _i:Int = i
+    while _i < heights.count-1 {
+        _i += 1
+        if heights[_i] < c {
+            break
+        }
+        j += 1
+    }
+
+    return j
+
+}
+
+func chart(_ heights:[Int]) -> String {
+
+    let max:Int        = heights.max()!
+    var chart:[String] = [String]()
+    var row:Int        = 1
+    var line:String    = ""
+    var size:String    = " "
+
+    for i in 1...max