arrayutil.java

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     * sequentially equal to the elements of arrb.
     */
    public static int countSameElements(byte[] arra, int start, byte[] arrb) {

        int k     = 0;
        int limit = arra.length - start;

        if (limit > arrb.length) {
            limit = arrb.length;
        }

        for (int i = 0; i < limit; i++) {
            if (arra[i + start] == arrb[i]) {
                k++;
            } else {
                break;
            }
        }

        return k;
    }

    /**
     * Returns the index of the first occurence of arrb in arra. Or -1 if not found.
     */
    public static int find(byte[] arra, int start, int limit, byte[] arrb) {

        int k = 0;

        limit = limit - arrb.length + 1;

        int value = arrb[0];

        for (; k < limit; k++) {
            if (arra[k] == value) {
                if (arrb.length == 1) {
                    return k;
                }

                if (containsAt(arra, k, arrb)) {
                    return k;
                }
            }
        }

        return -1;
    }

    /**
     * Returns an index into arra (or -1) where the character is not in the
     * charset byte array.
     */
    public static int findNotIn(byte[] arra, int start, int limit,
                                byte[] charset) {

        int k = 0;

        for (; k < limit; k++) {
            for (int i = 0; i < charset.length; i++) {
                if (arra[k] == charset[i]) {
                    continue;
                }
            }

            return k;
        }

        return -1;
    }

    /**
     * Returns an index into arra (or -1) where the character is in the
     * charset byte array.
     */
    public static int findIn(byte[] arra, int start, int limit,
                             byte[] charset) {

        int k = 0;

        for (; k < limit; k++) {
            for (int i = 0; i < charset.length; i++) {
                if (arra[k] == charset[i]) {
                    return k;
                }
            }
        }

        return -1;
    }

    /**
     * Returns the index of b or c in arra. Or -1 if not found.
     */
    public static int find(byte[] arra, int start, int limit, int b, int c) {

        int k = 0;

        for (; k < limit; k++) {
            if (arra[k] == b || arra[k] == c) {
                return k;
            }
        }

        return -1;
    }

    /**
     * Set elements of arrb true if their indexes appear in arrb.
     */
    public static void intIndexesToBooleanArray(int[] arra, boolean[] arrb) {

        int k = 0;

        for (int i = 0; i < arra.length; i++) {
            if (arra[i] < arrb.length) {
                arrb[arra[i]] = true;
            }
        }
    }

    /**
     * Return true if for each true element in arrb, the corresponding
     * element in arra is true
     */
    public static boolean containsAllTrueElements(boolean[] arra,
            boolean[] arrb) {

        for (int i = 0; i < arra.length; i++) {
            if (arrb[i] &&!arra[i]) {
                return false;
            }
        }

        return true;
    }

    /**
     * Returns true if arra from position start contains all elements of arrb
     * in sequential order.
     */
    public static boolean containsAt(byte[] arra, int start, byte[] arrb) {
        return countSameElements(arra, start, arrb) == arrb.length;
    }

    /**
     * Returns the count of elements in arra from position start that are
     * among the elements of arrb. Stops at any element not in arrb.
     */
    public static int countStartElementsAt(byte[] arra, int start,
                                           byte[] arrb) {

        int k = 0;

        mainloop:
        for (int i = start; i < arra.length; i++) {
            for (int j = 0; j < arrb.length; j++) {
                if (arra[i] == arrb[j]) {
                    k++;

                    continue mainloop;
                }
            }

            break;
        }

        return k;
    }

    /**
     * Returns the count of elements in arra from position start that are not
     * among the elements of arrb.
     *
     */
    public static int countNonStartElementsAt(byte[] arra, int start,
            byte[] arrb) {

        int k = 0;

        mainloop:
        for (int i = start; i < arra.length; i++) {
            for (int j = 0; j < arrb.length; j++) {
                if (arra[i] == arrb[j]) {
                    break mainloop;
                }
            }

            k++;
        }

        return k;
    }

    /**
     * Convenience wrapper for System.arraycopy().
     */
    public static void copyArray(Object source, Object dest, int count) {
        System.arraycopy(source, 0, dest, 0, count);
    }

    /**
     * Returns a range of elements of source from start to end of the array.
     */
    public static int[] arraySlice(int[] source, int start, int count) {

        int[] slice = new int[count];

        System.arraycopy(source, start, slice, 0, count);

        return slice;
    }

    /**
     * Fills the array with a value.
     */
    public static void fillArray(Object[] array, Object value) {

        int to = array.length;

        while (--to >= 0) {
            array[to] = value;
        }
    }

    /**
     * Fills the int array with a value
     */
    public static void fillArray(int[] array, int value) {

        int to = array.length;

        while (--to >= 0) {
            array[to] = value;
        }
    }

    /**
     * Returns a duplicates of an array.
     */
    public static Object duplicateArray(Object source) {

        int size = Array.getLength(source);
        Object newarray =
            Array.newInstance(source.getClass().getComponentType(), size);

        System.arraycopy(source, 0, newarray, 0, size);

        return newarray;
    }

    /**
     * Returns the given array if newsize is the same as existing.
     * Returns a new array of given size, containing as many elements of
     * the original array as it can hold.
     */
    public static Object resizeArrayIfDifferent(Object source, int newsize) {

        int oldsize = Array.getLength(source);

        if (oldsize == newsize) {
            return source;
        }

        Object newarray =
            Array.newInstance(source.getClass().getComponentType(), newsize);

        if (oldsize < newsize) {
            newsize = oldsize;
        }

        System.arraycopy(source, 0, newarray, 0, newsize);

        return newarray;
    }

    /**
     * Returns a new array of given size, containing as many elements of
     * the original array as it can hold. N.B. Always returns a new array
     * even if newsize parameter is the same as the old size.
     */
    public static Object resizeArray(Object source, int newsize) {

        Object newarray =
            Array.newInstance(source.getClass().getComponentType(), newsize);
        int oldsize = Array.getLength(source);

        if (oldsize < newsize) {
            newsize = oldsize;
        }

        System.arraycopy(source, 0, newarray, 0, newsize);

        return newarray;
    }

    /**
     * Returns an array containing the elements of parameter source, with one
     * element removed or added. Parameter adjust {-1, +1} indicates the
     * operation. Parameter colindex indicates the position at which an element
     * is removed or added. Parameter addition is an Object to add when
     * adjust is +1.
     */
    public static Object toAdjustedArray(Object source, Object addition,
                                         int colindex, int adjust) {

        int newsize = Array.getLength(source) + adjust;
        Object newarray =
            Array.newInstance(source.getClass().getComponentType(), newsize);

        copyAdjustArray(source, newarray, addition, colindex, adjust);

        return newarray;
    }

    /**
     *  Copies elements of source to dest. If adjust is -1 the element at
     *  colindex is not copied. If adjust is +1 that element is filled with
     *  the Object addition. All the rest of the elements in source are
     *  shifted left or right accordingly when they are copied. If adjust is 0
     *  the addition is copied over the element at colindex.
     *
     *  No checks are perfomed on array sizes and an exception is thrown
     *  if they are not consistent with the other arguments.
     */
    public static void copyAdjustArray(Object source, Object dest,
                                       Object addition, int colindex,
                                       int adjust) {

        int length = Array.getLength(source);

        if (colindex < 0) {
            System.arraycopy(source, 0, dest, 0, length);

            return;
        }

        System.arraycopy(source, 0, dest, 0, colindex);

        if (adjust == 0) {
            int endcount = length - colindex - 1;

            Array.set(dest, colindex, addition);

            if (endcount > 0) {
                System.arraycopy(source, colindex + 1, dest, colindex + 1,
                                 endcount);
            }
        } else if (adjust < 0) {
            int endcount = length - colindex - 1;

            if (endcount > 0) {
                System.arraycopy(source, colindex + 1, dest, colindex,
                                 endcount);
            }
        } else {
            int endcount = length - colindex;

            Array.set(dest, colindex, addition);

            if (endcount > 0) {
                System.arraycopy(source, colindex, dest, colindex + 1,
                                 endcount);
            }
        }
    }

    /**
     * Returns a new array with the elements in collar adjusted to reflect
     * changes at colindex. <p>
     *
     * Each element in collarr represents an index into another array
     * otherarr. <p>
     *
     * colindex is the index at which an element is added or removed.
     * Each element in the result array represents the new,
     * adjusted index. <p>
     *
     * For each element of collarr that represents an index equal to
     * colindex and adjust is -1, the result will not contain that element
     * and will be shorter than collar by one element.
     *
     * @param  colarr the source array
     * @param  colindex index at which to perform adjustement
     * @param  adjust +1, 0 or -1
     * @return new, adjusted array
     */
    public static int[] toAdjustedColumnArray(int[] colarr, int colindex,
            int adjust) {

        if (colarr == null) {
            return null;
        }

        int[] intarr = new int[colarr.length];
        int   j      = 0;

        for (int i = 0; i < colarr.length; i++) {
            if (colarr[i] > colindex) {
                intarr[j] = colarr[i] + adjust;

                j++;
            } else if (colarr[i] == colindex) {
                if (adjust < 0) {

                    // skip an element from colarr
                } else {
                    intarr[j] = colarr[i] + adjust;

                    j++;
                }
            } else {
                intarr[j] = colarr[i];

                j++;
            }
        }

        if (colarr.length != j) {
            int[] newarr = new int[j];

            copyArray(intarr, newarr, j);

            return newarr;
        }

        return intarr;
    }

    /**
     *  Copies some elements of row into colobject by using colindex as
     *  the list of indexes into row. <p>
     *
     *  colindex and colobject are of equal length and are normally
     *  shorter than row. <p>
     *
     *  @param row the source array
     *  @param colindex the list of indexes into row
     *  @param colobject the destination array
     */
    public static void copyColumnValues(Object[] row, int[] colindex,
                                        Object[] colobject) {

        for (int i = 0; i < colindex.length; i++) {
            colobject[i] = row[colindex[i]];
        }
    }

    public static void copyColumnValues(int[] row, int[] colindex,
                                        int[] colobject) {

        for (int i = 0; i < colindex.length; i++) {
            colobject[i] = row[colindex[i]];
        }
    }

    public static void fillSequence(int[] colindex) {

        for (int i = 0; i < colindex.length; i++) {
            colindex[i] = i;
        }
    }
/*
    public static void main(String[] args) {

        int[] a = new int[] {
            23, 11, 37, 7, 1, 5
        };
        int[] b = new int[] {
            1, 3, 7, 11, 13, 17, 19, 3, 1
        };
        int[] c = toAdjustedColumnArray(a, 7, -1);
        int[] d = toAdjustedColumnArray(b, 11, 1);
        int[] e = new int[a.length];

        copyArray(a, e, a.length);
        sortArray(e);

        int[] f = new int[b.length];

        copyArray(b, f, b.length);
        sortArray(f);

        boolean x = haveEqualSets(a, e, a.length);
        boolean y = haveEqualSets(b, f, b.length);

        System.out.print("test passed: ");
        System.out.print(x == true && y == true && c.length == a.length - 1
                         && d.length == b.length);
    }
*/
}