2 Perl scripts

2 files changed, 94 insertions, 0 deletions

diff --git a/challenge-083/cheok-yin-fung/perl/ch-1.pl b/challenge-083/cheok-yin-fung/perl/ch-1.pl
new file mode 100644
index 0000000000..d52d4a2055
--- /dev/null
+++ b/challenge-083/cheok-yin-fung/perl/ch-1.pl
@@ -0,0 +1,4 @@
+$_ = <STDIN>;
+/(^\w+\s)((\w+\s*)+)(\s\w+$)/;
+print length $2,"\n";
+
diff --git a/challenge-083/cheok-yin-fung/perl/ch-2.pl b/challenge-083/cheok-yin-fung/perl/ch-2.pl
new file mode 100644
index 0000000000..b117ae38bf
--- /dev/null
+++ b/challenge-083/cheok-yin-fung/perl/ch-2.pl
@@ -0,0 +1,90 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+#use Test::More tests => 4;
+
+if ($ARGV[0]) {
+    print fliparray([@ARGV]), "\n";
+} 
+else {
+    print join " ", 1..12,"\n";
+    print fliparray([1..12]), "\n";
+}
+
+sub num_of_1s_in_a_bit_string {
+    my $bitstr = $_[0];
+    my @temp = grep {$_ == 1} split "", $bitstr;
+    return scalar @temp;
+}
+
+sub make_bit_string {
+    my $len = $_[0];
+    my $dec = $_[1];
+    my $a = sprintf("%b", $dec);
+    my $addz = $len - length $a;
+    if ($addz > 0) {
+        $a = "0" x $addz . $a;
+    }
+    return $a;
+}
+
+sub sum_accord_to_bit_string {
+    my @arr = @{$_[0]};
+    my $bitstr = $_[1];
+    my $sum = 0;
+    my @sgn = split "",  $bitstr;
+    for my $i (0..$#arr) {
+        $sum -= $arr[$i] if $sgn[$i] == 1;
+        $sum += $arr[$i] if $sgn[$i] == 0;
+    }
+
+    return $sum;
+}
+
+
+sub fliparray {
+    my @arr = @{$_[0]};
+    my $minflip = $#arr;
+    my $recordmin = 0;
+    $recordmin += $_ for @arr;
+    my $recordflip = scalar @arr;
+
+    my $ans_arr;
+
+    for my $b (1..(2**scalar @arr) - 1) {
+        my $allsign = make_bit_string(scalar @arr,$b);
+        my $sum = sum_accord_to_bit_string(\@arr , $allsign);
+        if ( $sum <= $recordmin and $sum >= 0 ) {
+            $recordflip = scalar @arr if $sum < $recordmin;
+            $recordmin = $sum;
+            my $num_of_1s = num_of_1s_in_a_bit_string $allsign;
+            if ($recordflip > $num_of_1s and $sum == $recordmin) {
+                $recordflip = $num_of_1s; 
+                $ans_arr = $allsign;
+            }
+        }
+    }
+
+# assist checking result
+=pod
+    print $recordflip, "\n";
+    print $ans_arr, "\n";
+    for my $i (0..$#arr) {
+        my @sgn = split "", $ans_arr;
+        print " - " if $sgn[$i] == 1;
+        print " + " if $sgn[$i] == 0;
+        print $arr[$i];
+    }
+    print "\n";
+=cut
+
+    return $recordflip;
+}
+
+
+=pod
+ok fliparray([2,10,8]) == 1, "ten";
+ok fliparray([3,10,8]) == 1, "example 1";
+ok fliparray([1,2,3,4,5,6]) == 2, "one to six";
+ok fliparray([1,2,5,6,3,4]) == 2, "one to six,arr";
+=cut