+
+ /**
+ * Sorts both arrays to give ascending order by the first array, by first
+ * partitioning into zero and non-zero values before sorting the latter. This
+ * is faster than a direct call to charSortByFloat in the case where most of
+ * the array to be sorted is zero.
+ *
+ * @param arr
+ * @param s
+ */
+ public static void sort(float[] arr, char[] s)
+ {
+ /*
+ * Move all zero values to the front, non-zero to the back, while counting
+ * negative values
+ */
+ float[] f1 = new float[arr.length];
+ char[] s1 = new char[s.length];
+ int negativeCount = 0;
+ int zerosCount = 0;
+ int nextNonZeroValue = arr.length - 1;
+ for (int i = 0; i < arr.length; i++)
+ {
+ float val = arr[i];
+ if (val != 0f)
+ {
+ f1[nextNonZeroValue] = val;
+ s1[nextNonZeroValue] = s[i];
+ nextNonZeroValue--;
+ if (val < 0f)
+ {
+ negativeCount++;
+ }
+ }
+ else
+ {
+ f1[zerosCount] = val;
+ s1[zerosCount] = s[i];
+ zerosCount++;
+ }
+ }
+ int positiveCount = arr.length - zerosCount - negativeCount;
+
+ if (zerosCount == arr.length)
+ {
+ return; // all zero
+ }
+
+ /*
+ * sort the non-zero values
+ */
+ float[] nonZeroFloats = Arrays.copyOfRange(f1, zerosCount, f1.length);
+ char[] nonZeroChars = Arrays.copyOfRange(s1, zerosCount, s1.length);
+ charSortByFloat(nonZeroFloats, nonZeroChars, true);
+
+ /*
+ * Backfill zero values to original arrays, after the space reserved for
+ * negatives
+ */
+ System.arraycopy(f1, 0, arr, negativeCount, zerosCount);
+ System.arraycopy(s1, 0, s, negativeCount, zerosCount);
+
+ /*
+ * Copy sorted negative values to the front of arr, s
+ */
+ System.arraycopy(nonZeroFloats, 0, arr, 0, negativeCount);
+ System.arraycopy(nonZeroChars, 0, s, 0, negativeCount);
+
+ /*
+ * Copy sorted positive values after the negatives and zeros
+ */
+ System.arraycopy(nonZeroFloats, negativeCount, arr, negativeCount
+ + zerosCount, positiveCount);
+ System.arraycopy(nonZeroChars, negativeCount, s, negativeCount
+ + zerosCount, positiveCount);
+ }
+
+ /**
+ * Sorts arrays of float and char by the float values, by making an array of
+ * indices, and sorting it using a comparator that refers to the float values.
+ *
+ * @see http
+ * ://stackoverflow.com/questions/4859261/get-the-indices-of-an-array-
+ * after-sorting
+ * @param arr
+ * @param s
+ * @param ascending
+ */
+ public static void charSortByFloat(float[] arr, char[] s,
+ boolean ascending)
+ {
+ final int length = arr.length;
+ Integer[] indices = makeIndexArray(length);
+ Arrays.sort(indices, new FloatComparator(arr, ascending));
+
+ /*
+ * Copy the array values as per the sorted indices
+ */
+ float[] sortedFloats = new float[length];
+ char[] sortedChars = new char[s.length];
+ for (int i = 0; i < length; i++)
+ {
+ sortedFloats[i] = arr[indices[i]];
+ sortedChars[i] = s[indices[i]];
+ }
+
+ /*
+ * And copy the sorted values back into the arrays
+ */
+ System.arraycopy(sortedFloats, 0, arr, 0, length);
+ System.arraycopy(sortedChars, 0, s, 0, s.length);
+ }
+
+ /**
+ * Make an array whose values are 0...length.
+ *
+ * @param length
+ * @return
+ */
+ protected static Integer[] makeIndexArray(final int length)
+ {
+ Integer[] indices = new Integer[length];
+ for (int i = 0; i < length; i++)
+ {
+ indices[i] = i;
+ }
+ return indices;
+ }
+
+ static void sort(float[] arr, int p, int r, char[] s)
+ {
+ int q;
+ if (p < r)
+ {
+ q = partition(arr, p, r, s);
+ sort(arr, p, q, s);
+ sort(arr, q + 1, r, s);
+ }
+ }
+
+ /**
+ * Sorts both arrays to give ascending order in the first array, by first
+ * partitioning into zero and non-zero values before sorting the latter. This
+ * is faster than a direct call to charSortByInt in the case where most of the
+ * array to be sorted is zero.
+ *
+ * @param arr
+ * @param s
+ */
+ public static void sort(int[] arr, char[] s)
+ { /*
+ * Move all zero values to the front, non-zero to the back, while counting
+ * negative values
+ */
+ int[] f1 = new int[arr.length];
+ char[] s1 = new char[s.length];
+ int negativeCount = 0;
+ int zerosCount = 0;
+ int nextNonZeroValue = arr.length - 1;
+ for (int i = 0; i < arr.length; i++)
+ {
+ int val = arr[i];
+ if (val != 0f)
+ {
+ f1[nextNonZeroValue] = val;
+ s1[nextNonZeroValue] = s[i];
+ nextNonZeroValue--;
+ if (val < 0)
+ {
+ negativeCount++;
+ }
+ }
+ else
+ {
+ f1[zerosCount] = val;
+ s1[zerosCount] = s[i];
+ zerosCount++;
+ }
+ }
+ int positiveCount = arr.length - zerosCount - negativeCount;
+
+ if (zerosCount == arr.length)
+ {
+ return; // all zero
+ }
+
+ /*
+ * sort the non-zero values
+ */
+ int[] nonZeroInts = Arrays.copyOfRange(f1, zerosCount, f1.length);
+ char[] nonZeroChars = Arrays.copyOfRange(s1, zerosCount, s1.length);
+ charSortByInt(nonZeroInts, nonZeroChars, true);
+
+ /*
+ * Backfill zero values to original arrays, after the space reserved for
+ * negatives
+ */
+ System.arraycopy(f1, 0, arr, negativeCount, zerosCount);
+ System.arraycopy(s1, 0, s, negativeCount, zerosCount);
+
+ /*
+ * Copy sorted negative values to the front of arr, s
+ */
+ System.arraycopy(nonZeroInts, 0, arr, 0, negativeCount);
+ System.arraycopy(nonZeroChars, 0, s, 0, negativeCount);
+
+ /*
+ * Copy sorted positive values after the negatives and zeros
+ */
+ System.arraycopy(nonZeroInts, negativeCount, arr, negativeCount
+ + zerosCount, positiveCount);
+ System.arraycopy(nonZeroChars, negativeCount, s, negativeCount
+ + zerosCount, positiveCount);
+ }
+
+ /**
+ * Sorts arrays of int and char, by making an array of indices, and sorting it
+ * using a comparator that refers to the int values.
+ *
+ * @see http
+ * ://stackoverflow.com/questions/4859261/get-the-indices-of-an-array-
+ * after-sorting
+ * @param arr
+ * @param s
+ * @param ascending
+ */
+ public static void charSortByInt(int[] arr, char[] s, boolean ascending)
+ {
+ final int length = arr.length;
+ Integer[] indices = makeIndexArray(length);
+ Arrays.sort(indices, new IntComparator(arr, ascending));
+
+ /*
+ * Copy the array values as per the sorted indices
+ */
+ int[] sortedInts = new int[length];
+ char[] sortedChars = new char[s.length];
+ for (int i = 0; i < length; i++)
+ {
+ sortedInts[i] = arr[indices[i]];
+ sortedChars[i] = s[indices[i]];
+ }
+
+ /*
+ * And copy the sorted values back into the arrays
+ */
+ System.arraycopy(sortedInts, 0, arr, 0, length);
+ System.arraycopy(sortedChars, 0, s, 0, s.length);
+ }
+
+ /**
+ * Sorts arrays of int and Object, by making an array of indices, and sorting
+ * it using a comparator that refers to the int values.
+ *
+ * @see http
+ * ://stackoverflow.com/questions/4859261/get-the-indices-of-an-array-
+ * after-sorting
+ * @param arr
+ * @param s
+ * @param ascending
+ */
+ public static void sortByInt(int[] arr, Object[] s, boolean ascending)
+ {
+ final int length = arr.length;
+ Integer[] indices = makeIndexArray(length);
+ Arrays.sort(indices, new IntComparator(arr, ascending));
+
+ /*
+ * Copy the array values as per the sorted indices
+ */
+ int[] sortedInts = new int[length];
+ Object[] sortedObjects = new Object[s.length];
+ for (int i = 0; i < length; i++)
+ {
+ sortedInts[i] = arr[indices[i]];
+ sortedObjects[i] = s[indices[i]];
+ }
+
+ /*
+ * And copy the sorted values back into the arrays
+ */
+ System.arraycopy(sortedInts, 0, arr, 0, length);
+ System.arraycopy(sortedObjects, 0, s, 0, s.length);
+ }
+
+ /**
+ * Sorts arrays of String and Object, by making an array of indices, and
+ * sorting it using a comparator that refers to the String values. Both arrays
+ * are sorted by case-sensitive order of the string array values.
+ *
+ * @see http
+ * ://stackoverflow.com/questions/4859261/get-the-indices-of-an-array-
+ * after-sorting
+ * @param arr
+ * @param s
+ * @param ascending
+ */
+ public static void sortByString(String[] arr, Object[] s,
+ boolean ascending)
+ {
+ final int length = arr.length;
+ Integer[] indices = makeIndexArray(length);
+ Arrays.sort(indices, new ExternalComparator(arr, ascending));
+
+ /*
+ * Copy the array values as per the sorted indices
+ */
+ String[] sortedStrings = new String[length];
+ Object[] sortedObjects = new Object[s.length];
+ for (int i = 0; i < length; i++)
+ {
+ sortedStrings[i] = arr[indices[i]];
+ sortedObjects[i] = s[indices[i]];
+ }
+
+ /*
+ * And copy the sorted values back into the arrays
+ */
+ System.arraycopy(sortedStrings, 0, arr, 0, length);
+ System.arraycopy(sortedObjects, 0, s, 0, s.length);
+ }
+
+ /**
+ * Sorts arrays of double and Object, by making an array of indices, and
+ * sorting it using a comparator that refers to the double values.
+ *
+ * @see http
+ * ://stackoverflow.com/questions/4859261/get-the-indices-of-an-array-
+ * after-sorting
+ * @param arr
+ * @param s
+ * @param ascending
+ */
+ public static void sortByDouble(double[] arr, Object[] s,
+ boolean ascending)
+ {
+ final int length = arr.length;
+ Integer[] indices = makeIndexArray(length);
+ Arrays.sort(indices, new DoubleComparator(arr, ascending));
+
+ /*
+ * Copy the array values as per the sorted indices
+ */
+ double[] sortedDoubles = new double[length];
+ Object[] sortedObjects = new Object[s.length];
+ for (int i = 0; i < length; i++)
+ {
+ sortedDoubles[i] = arr[indices[i]];
+ sortedObjects[i] = s[indices[i]];
+ }
+
+ /*
+ * And copy the sorted values back into the arrays
+ */
+ System.arraycopy(sortedDoubles, 0, arr, 0, length);
+ System.arraycopy(sortedObjects, 0, s, 0, s.length);
+ }