Java Array Sort sortByIndex(int start, int end, int[] indexes, double[] values)

Description

In-place sort of two arrays, only indexes is used for comparison and values of same position are sorted accordingly.

License

Apache License

Parameter

Parameter	Description
start	starting index
end	ending index
indexes	array of indexes to sort by
values	double array of values to sort

Declaration

public static void sortByIndex(int start, int end, int[] indexes, double[] values) 

Method Source Code

//package com.java2s;
/*//from   w w  w  .  j a  v  a 2 s.  co m
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

public class Main {
    /**
     * In-place sort of two arrays, only indexes is used for comparison and values
     * of same position are sorted accordingly. 
     * 
      * @param start starting index
      * @param end ending index
      * @param indexes array of indexes to sort by
      * @param values double array of values to sort
      */
    public static void sortByIndex(int start, int end, int[] indexes, double[] values) {
        int tempIx;
        double tempVal;

        int length = end - start;
        if (length < 7) {
            for (int i = start + 1; i < end; i++) {
                for (int j = i; j > start && indexes[j - 1] > indexes[j]; j--) {
                    tempIx = indexes[j];
                    indexes[j] = indexes[j - 1];
                    indexes[j - 1] = tempIx;
                    tempVal = values[j];
                    values[j] = values[j - 1];
                    values[j - 1] = tempVal;
                }
            }
            return;
        }
        int middle = (start + end) / 2;
        if (length > 7) {
            int bottom = start;
            int top = end - 1;
            if (length > 40) {
                length /= 8;
                bottom = med3(indexes, bottom, bottom + length, bottom + (2 * length));
                middle = med3(indexes, middle - length, middle, middle + length);
                top = med3(indexes, top - (2 * length), top - length, top);
            }
            middle = med3(indexes, bottom, middle, top);
        }
        int partionValue = indexes[middle];
        int a, b, c, d;
        a = b = start;
        c = d = end - 1;
        while (true) {
            while (b <= c && indexes[b] <= partionValue) {
                if (indexes[b] == partionValue) {
                    tempIx = indexes[a];
                    indexes[a] = indexes[b];
                    indexes[b] = tempIx;
                    tempVal = values[a];
                    values[a++] = values[b];
                    values[b] = tempVal;
                }
                b++;
            }
            while (c >= b && indexes[c] >= partionValue) {
                if (indexes[c] == partionValue) {
                    tempIx = indexes[c];
                    indexes[c] = indexes[d];
                    indexes[d] = tempIx;
                    tempVal = values[c];
                    values[c] = values[d];
                    values[d--] = tempVal;
                }
                c--;
            }
            if (b > c) {
                break;
            }
            tempIx = indexes[b];
            indexes[b] = indexes[c];
            indexes[c] = tempIx;
            tempVal = values[b];
            values[b++] = values[c];
            values[c--] = tempVal;
        }
        length = a - start < b - a ? a - start : b - a;
        int l = start;
        int h = b - length;
        while (length-- > 0) {
            tempIx = indexes[l];
            indexes[l] = indexes[h];
            indexes[h] = tempIx;
            tempVal = values[l];
            values[l++] = values[h];
            values[h++] = tempVal;
        }
        length = d - c < end - 1 - d ? d - c : end - 1 - d;
        l = b;
        h = end - length;
        while (length-- > 0) {
            tempIx = indexes[l];
            indexes[l] = indexes[h];
            indexes[h] = tempIx;
            tempVal = values[l];
            values[l++] = values[h];
            values[h++] = tempVal;
        }
        if ((length = b - a) > 0) {
            sortByIndex(start, start + length, indexes, values);
        }
        if ((length = d - c) > 0) {
            sortByIndex(end - length, end, indexes, values);
        }
    }

    /**
    * In-place sort of three arrays, only first indexes is used for comparison and second
    * indexes as well as values of same position are sorted accordingly. 
    * 
     * @param start starting index
     * @param end ending index
     * @param indexes ?
     * @param indexes2 ?
     * @param values ?
     */
    public static void sortByIndex(int start, int end, int[] indexes, int[] indexes2, double[] values) {
        int tempIx;
        int tempIx2;
        double tempVal;

        int length = end - start;
        if (length < 7) {
            for (int i = start + 1; i < end; i++) {
                for (int j = i; j > start && indexes[j - 1] > indexes[j]; j--) {
                    tempIx = indexes[j];
                    indexes[j] = indexes[j - 1];
                    indexes[j - 1] = tempIx;
                    tempIx2 = indexes2[j];
                    indexes2[j] = indexes2[j - 1];
                    indexes2[j - 1] = tempIx2;
                    tempVal = values[j];
                    values[j] = values[j - 1];
                    values[j - 1] = tempVal;
                }
            }
            return;
        }
        int middle = (start + end) / 2;
        if (length > 7) {
            int bottom = start;
            int top = end - 1;
            if (length > 40) {
                length /= 8;
                bottom = med3(indexes, bottom, bottom + length, bottom + (2 * length));
                middle = med3(indexes, middle - length, middle, middle + length);
                top = med3(indexes, top - (2 * length), top - length, top);
            }
            middle = med3(indexes, bottom, middle, top);
        }
        int partionValue = indexes[middle];
        int a, b, c, d;
        a = b = start;
        c = d = end - 1;
        while (true) {
            while (b <= c && indexes[b] <= partionValue) {
                if (indexes[b] == partionValue) {
                    tempIx = indexes[a];
                    indexes[a] = indexes[b];
                    indexes[b] = tempIx;
                    tempIx2 = indexes2[a];
                    indexes2[a] = indexes2[b];
                    indexes2[b] = tempIx2;
                    tempVal = values[a];
                    values[a++] = values[b];
                    values[b] = tempVal;
                }
                b++;
            }
            while (c >= b && indexes[c] >= partionValue) {
                if (indexes[c] == partionValue) {
                    tempIx = indexes[c];
                    indexes[c] = indexes[d];
                    indexes[d] = tempIx;
                    tempIx2 = indexes2[c];
                    indexes2[c] = indexes2[d];
                    indexes2[d] = tempIx2;
                    tempVal = values[c];
                    values[c] = values[d];
                    values[d--] = tempVal;
                }
                c--;
            }
            if (b > c) {
                break;
            }
            tempIx = indexes[b];
            indexes[b] = indexes[c];
            indexes[c] = tempIx;
            tempIx2 = indexes2[b];
            indexes2[b] = indexes2[c];
            indexes2[c] = tempIx2;
            tempVal = values[b];
            values[b++] = values[c];
            values[c--] = tempVal;
        }
        length = a - start < b - a ? a - start : b - a;
        int l = start;
        int h = b - length;
        while (length-- > 0) {
            tempIx = indexes[l];
            indexes[l] = indexes[h];
            indexes[h] = tempIx;
            tempIx2 = indexes2[l];
            indexes2[l] = indexes2[h];
            indexes2[h] = tempIx2;
            tempVal = values[l];
            values[l++] = values[h];
            values[h++] = tempVal;
        }
        length = d - c < end - 1 - d ? d - c : end - 1 - d;
        l = b;
        h = end - length;
        while (length-- > 0) {
            tempIx = indexes[l];
            indexes[l] = indexes[h];
            indexes[h] = tempIx;
            tempIx2 = indexes2[l];
            indexes2[l] = indexes2[h];
            indexes2[h] = tempIx2;
            tempVal = values[l];
            values[l++] = values[h];
            values[h++] = tempVal;
        }
        if ((length = b - a) > 0) {
            sortByIndex(start, start + length, indexes, indexes2, values);
        }
        if ((length = d - c) > 0) {
            sortByIndex(end - length, end, indexes, indexes2, values);
        }
    }

    private static int med3(int[] array, int a, int b, int c) {
        int x = array[a], y = array[b], z = array[c];
        return x < y ? (y < z ? b : (x < z ? c : a)) : (y > z ? b : (x > z ? c : a));
    }

    private static int med3(double[] array, int a, int b, int c) {
        double x = array[a], y = array[b], z = array[c];
        return x < y ? (y < z ? b : (x < z ? c : a)) : (y > z ? b : (x > z ? c : a));
    }
}

Related

1. sortArray(int[] a)
2. sortArray(int[] array)
3. sortArrayAndReturnIndex(double[] p, String t)
4. sortByFirst(int[] array1, int[] array2)
5. sortByIndex(final double[] data, int size)
6. sortByIndex(int start, int end, int[] indexes, double[] values)
7. sortByLength(String[] proposals)
8. sortByLengthDesc(String[] ss)
9. sortByString(Object[] array)