tasks a-s

Task/Range-extraction/JavaScript/range-extraction.js

@@ -0,0 +1,35 @@
+function rangeExtraction(list) {
+  var len = list.length;
+  var out = [];
+  var i, j;
+
+  for (i = 0; i < len; i = j + 1) {
+    // beginning of range or single
+    out.push(list[i]);
+
+    // find end of range
+    for (var j = i + 1; j < len && list[j] == list[j-1] + 1; j++);
+    j--;
+
+    if (i == j) {
+      // single number
+      out.push(",");
+    } else if (i + 1 == j) {
+      // two numbers
+      out.push(",", list[j], ",");
+    } else {
+      // range
+      out.push("-", list[j], ",");
+    }
+  }
+  out.pop(); // remove trailing comma
+  return out.join("");
+}
+
+// using print function as supplied by Rhino standalone
+print(rangeExtraction([
+  0,  1,  2,  4,  6,  7,  8, 11, 12, 14,
+  15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
+  25, 27, 28, 29, 30, 31, 32, 33, 35, 36,
+  37, 38, 39
+]));