imported my solutions to this week's challenges - I think there was a bug in task 2? - see README

3 files changed, 160 insertions, 34 deletions

diff --git a/challenge-122/duncan-c-white/README b/challenge-122/duncan-c-white/README
index a67e73b42b..943444f99f 100644
--- a/challenge-122/duncan-c-white/README
+++ b/challenge-122/duncan-c-white/README
@@ -1,51 +1,57 @@
-Task 1: "Invert Bit
+Task 1: "Average of Stream
 
-You are given integers 0 <= $m <= 255 and 1 <= $n <= 8.
+You are given a stream of numbers, @N.
 
-Write a script to invert $n bit from the end of the binary representation
-of $m and print the decimal representation of the new binary number.
+Write a script to print the average of the stream at every point.
 
 Example
 
-  Input: $m = 12, $n = 3
-  Output: 8
+Input: @N = (10, 20, 30, 40, 50, 60, 70, 80, 90, ...)
+Output:      10, 15, 20, 25, 30, 35, 40, 45, 50, ...
 
-Binary representation of $m = 00001100
-Invert 3rd bit from the end = 00001000
-Decimal equivalent of 00001000 = 8
-
-  Input $m = 18, $n = 4
-  Output: 26
-
-Binary representation of $m = 00010010
-Invert 4th bit from the end = 00011010
-Decimal equivalent of 00011010 = 26
+Average of first number is 10.
+Average of first 2 numbers (10+20)/2 = 15
+Average of first 3 numbers (10+20+30)/3 = 20
+Average of first 4 numbers (10+20+30+40)/4 = 25 and so on.
 "
 
-My notes: trivial again.
+My notes: sounds quite simple, just requires a running total.
 
 
-Task 2: "Travelling Salesman
-Submitted by: Jorg Sommrey
+Task 2: "Basketball Points
 
-You are given a NxN matrix containing the distances between N cities.
+You are given a score $S.
 
-Write a script to find a round trip of minimum length visiting all N
-cities exactly once and returning to the start.
+You can win basketball points e.g. 1 point, 2 points and 3 points.
 
-Example
+Write a script to find out the different ways you can score $S.
 
-Matrix: [0, 5, 2, 7]
-        [5, 0, 5, 3]
-        [3, 1, 0, 6]
-        [4, 5, 4, 0]
-
-Output:
-        length = 10
-        tour = (0 2 1 3 0)
+Example
 
-BONUS 1: For a given number N, create a random NxN distance matrix and find a solution for this matrix.
-BONUS 2: Find a solution for a random matrix of size 15x15 or 20x20
+Input: $S = 4
+Output: 1 1 1 1
+        1 1 2
+        1 2 1
+        1 3
+        2 1 1
+        2 2
+        3 1
+
+Input: $S = 5
+Output: 1 1 1 1 1
+        1 1 1 2
+        1 1 2 1
+        1 1 3
+        1 2 1 1
+        1 2 2
+        1 3 1
+        2 1 1 1
+        2 1 2
+        2 2 1
+        2 3
+        3 1 1
 "
 
-My notes: gurk!  TSP is hard.  I'm tired and I'm not doing that.
+My notes: Assuming I'm understanding it right, all combinations of
+removing 1, 2 or 3 from N repeatedly.  Easyish (recursive).
+NOTE: surely the $S = 5 example omits one last solution "3 2"?
diff --git a/challenge-122/duncan-c-white/perl/ch-1.pl b/challenge-122/duncan-c-white/perl/ch-1.pl
new file mode 100755
index 0000000000..4562cd7ac2
--- /dev/null
+++ b/challenge-122/duncan-c-white/perl/ch-1.pl
@@ -0,0 +1,40 @@
+#!/usr/bin/perl
+# 
+# Task 1: "Average of Stream
+# 
+# You are given a stream of numbers, @N.
+# 
+# Write a script to print the average of the stream at every point.
+# 
+# Example
+# 
+# Input: @N = (10, 20, 30, 40, 50, 60, 70, 80, 90, ...)
+# Output:      10, 15, 20, 25, 30, 35, 40, 45, 50, ...
+# 
+# Average of first number is 10.
+# Average of first 2 numbers (10+20)/2 = 15
+# Average of first 3 numbers (10+20+30)/3 = 20
+# Average of first 4 numbers (10+20+30+40)/4 = 25 and so on.
+# "
+# 
+# My notes: sounds quite simple, just requires a running total.
+# 
+
+use strict;
+use warnings;
+use feature 'say';
+#use Data::Dumper;
+
+die "Usage: stream-average N1 N2...\n" if @ARGV == 0;
+my @n = @ARGV;
+
+my $sum = 0;
+my $n = 0;
+foreach my $val (@n)
+{
+	$sum += $val;
+	$n++;
+	print "," if $n>1;
+	print $sum/$n;
+}
+say "";
diff --git a/challenge-122/duncan-c-white/perl/ch-2.pl b/challenge-122/duncan-c-white/perl/ch-2.pl
new file mode 100755
index 0000000000..d60decb34c
--- /dev/null
+++ b/challenge-122/duncan-c-white/perl/ch-2.pl
@@ -0,0 +1,80 @@
+#!/usr/bin/perl
+# 
+# Task 2: "Basketball Points
+# 
+# You are given a score $S.
+# 
+# You can win basketball points e.g. 1 point, 2 points and 3 points.
+# 
+# Write a script to find out the different ways you can score $S.
+# 
+# Example
+# 
+# Input: $S = 4
+# Output: 1 1 1 1
+#         1 1 2
+#         1 2 1
+#         1 3
+#         2 1 1
+#         2 2
+#         3 1
+# 
+# Input: $S = 5
+# Output: 1 1 1 1 1
+#         1 1 1 2
+#         1 1 2 1
+#         1 1 3
+#         1 2 1 1
+#         1 2 2
+#         1 3 1
+#         2 1 1 1
+#         2 1 2
+#         2 2 1
+#         2 3
+#         3 1 1
+# "
+# 
+# My notes: Assuming I'm understanding it right, all combinations of
+# removing 1, 2 or 3 from N repeatedly.  Easyish (recursive).
+# NOTE: surely the $S = 5 example omits one last solution "3 2"?
+# 
+
+use strict;
+use warnings;
+use feature 'say';
+use Function::Parameters;
+use Getopt::Long;
+use Data::Dumper;
+
+my $debug = 0;
+die "Usage: basketball-points N\n" unless
+	GetOptions( "debug" => \$debug ) && @ARGV==1;
+my $n = shift;
+die "basketball-points: N ($n) > 0\n" if $n<1;
+
+bp( $n, "" );
+
+
+#
+# bp( $n, $prefix );
+#	Print out all basketball-point combinations of $n given
+#	a prefix (such as "1 1 2") $prefix.
+#
+fun bp( $n, $prefix )
+{
+	if( $n >= 1 )
+	{
+		say "$prefix $n" if $n == 1;
+		bp( $n-1, "$prefix 1" ) if $n > 1;
+	}
+	if( $n >= 2 )
+	{
+		say "$prefix $n" if $n == 2;
+		bp( $n-2, "$prefix 2" ) if $n > 2;
+	}
+	if( $n >= 3 )
+	{
+		say "$prefix $n" if $n == 3;
+		bp( $n-3, "$prefix 3" ) if $n > 3;
+	}
+}