1 files changed, 28 insertions, 0 deletions
diff --git a/ch-1.pl b/ch-1.pl
new file mode 100644
index 0000000000..f33a6aff99
--- /dev/null
+++ b/ch-1.pl
@@ -0,0 +1,28 @@
+#!/usr/bin/perl
+use strict;
+
+# Usage: $ ch-1.pl (number of terms) (diff-k) (LIST of N sorted integers, from small to large)
+# ch-1.pl 3 1 1 2 3
+
+my $N = shift @ARGV;
+my $DIFFK = shift @ARGV;
+
+die "not enough terms or too many terms" if $N != $#ARGV+1;
+
+my @A = @ARGV;
+
+my @B;
+
+for (1..$N-1) {
+    push @B, $A[$_] - $A[$_-1];
+}
+
+for (0..$N-2) {
+    my $diff = 0;
+    my $pointer = $_+1;
+    while ($pointer < $N and $diff <= $DIFFK) {
+        $diff += $B[$pointer-1];
+        print $pointer, " ", $_, "\n" if $diff==$DIFFK;
+        $pointer++;
+    }
+}