+ /**
+ * Adds the given range to a list of ranges. If the new range just extends
+ * existing ranges, the current endpoint is updated instead.
+ *
+ * @param range
+ * @param addTo
+ */
+ public static void addRange(int[] range, List<int[]> addTo)
+ {
+ /*
+ * list is empty - add to it!
+ */
+ if (addTo.size() == 0)
+ {
+ addTo.add(range);
+ return;
+ }
+
+ int[] last = addTo.get(addTo.size() - 1);
+ boolean lastForward = last[1] >= last[0];
+ boolean newForward = range[1] >= range[0];
+
+ /*
+ * contiguous range in the same direction - just update endpoint
+ */
+ if (lastForward == newForward && last[1] == range[0])
+ {
+ last[1] = range[1];
+ return;
+ }
+
+ /*
+ * next range starts at +1 in forward sense - update endpoint
+ */
+ if (lastForward && newForward && range[0] == last[1] + 1)
+ {
+ last[1] = range[1];
+ return;
+ }
+
+ /*
+ * next range starts at -1 in reverse sense - update endpoint
+ */
+ if (!lastForward && !newForward && range[0] == last[1] - 1)
+ {
+ last[1] = range[1];
+ return;
+ }
+
+ /*
+ * just add the new range
+ */
+ addTo.add(range);
+ }