- Added solutions by Arne Sommer.

1 files changed, 62 insertions, 0 deletions

diff --git a/challenge-070/arne-sommer/node/gray-code-seq-node b/challenge-070/arne-sommer/node/gray-code-seq-node
new file mode 100755
index 0000000000..c3e831c06f
--- /dev/null
+++ b/challenge-070/arne-sommer/node/gray-code-seq-node
@@ -0,0 +1,62 @@
+#! /usr/bin/env node
+
+var N = process.argv[2] || 3;
+
+var verbose = false;
+
+if (N == '--verbose') 
+{
+  verbose = true;
+  N = process.argv[3] || 3;
+}
+
+let die = (message) => {
+    console.log(message);
+    process.kill(process.pid);
+};
+
+var NN = parseInt(N);
+
+if (NN != N || NN < 2 || NN > 5)
+    die('N: Integer 2,3,4,5 only');
+
+var sequence = [0,1,3,2];
+
+let asBinary = (value, length) => {
+  var binary =  value.toString(2);
+
+  while (binary.length < length)
+    binary = "0" + binary;
+
+  return binary;
+}
+
+let generate2bgcs = (array, level) => {
+  var S1a = array.map(x => asBinary(x,level-1) );
+  var S2a = S1a.slice(); S2a.reverse();
+  var S1  = S1a.map(x => '0' + x);
+  var S2  = S2a.map(x => '1' + x);
+  var S3  = S1; for (x of S2) { S3.push(x); }
+  var out = S3.map( x => parseInt(x, 2) );
+  
+  if (verbose)
+  {
+    console.log(': in: ' + array);
+    console.log(': a) S1 = ' + S1a);
+    console.log(': b) S2 = ' + S2a);
+    console.log(': c) S1 = ' + S1);
+    console.log(': d) S2 = ' + S2);
+    console.log(': e) S3 = ' + S3);
+    console.log(': out: ' + out);
+  }
+
+  return out;
+}
+
+for (level = 3; level <= NN; level++)
+{
+  sequence = generate2bgcs(sequence, level);
+}
+
+console.log(sequence);
+