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/*
* Copyright (C) 2009-2017 Sebastiano Vigna
*
* Licensed 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.
*
*
*
* Copyright (C) 1999 CERN - European Organization for Nuclear Research.
*
* Permission to use, copy, modify, distribute and sell this software and
* its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and that
* both that copyright notice and this permission notice appear in
* supporting documentation. CERN makes no representations about the
* suitability of this software for any purpose. It is provided "as is"
* without expressed or implied warranty.
*/
package PACKAGE;
import java.util.Arrays;
import java.util.Random;
import it.unimi.dsi.fastutil.BigArrays;
import it.unimi.dsi.fastutil.Hash;
import static it.unimi.dsi.fastutil.BigArrays.ensureLength;
import static it.unimi.dsi.fastutil.BigArrays.start;
import static it.unimi.dsi.fastutil.BigArrays.segment;
import static it.unimi.dsi.fastutil.BigArrays.displacement;
import static it.unimi.dsi.fastutil.BigArrays.SEGMENT_MASK;
import static it.unimi.dsi.fastutil.BigArrays.SEGMENT_SHIFT;
import static it.unimi.dsi.fastutil.BigArrays.SEGMENT_SIZE;
#if KEYS_PRIMITIVE
#if ! KEY_CLASS_Byte && ! KEY_CLASS_Boolean
import it.unimi.dsi.fastutil.bytes.ByteBigArrays;
#endif
/** A class providing static methods and objects that do useful things with {@linkplain BigArrays big arrays}.
*
* In particular, the ensureCapacity(), grow(),
* trim() and setLength() methods allow to handle
* big arrays much like array lists.
*
*
Note that {@link it.unimi.dsi.fastutil.io.BinIO} and {@link it.unimi.dsi.fastutil.io.TextIO}
* contain several methods that make it possible to load and save big arrays of primitive types as sequences
* of elements in {@link java.io.DataInput} format (i.e., not as objects) or as sequences of lines of text.
*
* @see BigArrays
*/
public class BIG_ARRAYS {
#else
import java.util.Comparator;
/** A class providing static methods and objects that do useful things with {@linkplain BigArrays big arrays}.
*
*
In particular, the ensureCapacity(), grow(),
* trim() and setLength() methods allow to handle
* arrays much like array lists.
*
*
Note that {@link it.unimi.dsi.fastutil.io.BinIO} and {@link it.unimi.dsi.fastutil.io.TextIO}
* contain several methods make it possible to load and save big arrays of primitive types as sequences
* of elements in {@link java.io.DataInput} format (i.e., not as objects) or as sequences of lines of text.
*
*
Warning: creating arrays
* using {@linkplain java.lang.reflect.Array#newInstance(Class,int) reflection}, as it
* happens in {@link #ensureCapacity(Object[][],long,long)} and {@link #grow(Object[][],long,long)},
* is significantly slower than using new. This phenomenon is particularly
* evident in the first growth phases of an array reallocated with doubling (or similar) logic.
*
* @see BigArrays
*/
public class BIG_ARRAYS {
#endif
private BIG_ARRAYS() {}
/** A static, final, empty big array. */
public final static KEY_TYPE[][] EMPTY_BIG_ARRAY = {};
/** Returns the element of the given big array of specified index.
*
* @param array a big array.
* @param index a position in the big array.
* @return the element of the big array at the specified position.
*/
public static KEY_GENERIC KEY_GENERIC_TYPE get(final KEY_GENERIC_TYPE[][] array, final long index) {
return array[segment(index)][displacement(index)];
}
/** Sets the element of the given big array of specified index.
*
* @param array a big array.
* @param index a position in the big array.
* @param value the new value for the array element at the specified position.
*/
public static KEY_GENERIC void set(final KEY_GENERIC_TYPE[][] array, final long index, KEY_GENERIC_TYPE value) {
array[segment(index)][displacement(index)] = value;
}
/** Swaps the element of the given big array of specified indices.
*
* @param array a big array.
* @param first a position in the big array.
* @param second a position in the big array.
*/
public static KEY_GENERIC void swap(final KEY_GENERIC_TYPE[][] array, final long first, final long second) {
final KEY_GENERIC_TYPE t = array[segment(first)][displacement(first)];
array[segment(first)][displacement(first)] = array[segment(second)][displacement(second)];
array[segment(second)][displacement(second)] = t;
}
#if KEYS_PRIMITIVE && ! KEY_CLASS_Boolean
/** Adds the specified increment the element of the given big array of specified index.
*
* @param array a big array.
* @param index a position in the big array.
* @param incr the increment
*/
public static void add(final KEY_GENERIC_TYPE[][] array, final long index, KEY_GENERIC_TYPE incr) {
array[segment(index)][displacement(index)] += incr;
}
/** Multiplies by the specified factor the element of the given big array of specified index.
*
* @param array a big array.
* @param index a position in the big array.
* @param factor the factor
*/
public static void mul(final KEY_GENERIC_TYPE[][] array, final long index, KEY_GENERIC_TYPE factor) {
array[segment(index)][displacement(index)] *= factor;
}
/** Increments the element of the given big array of specified index.
*
* @param array a big array.
* @param index a position in the big array.
*/
public static void incr(final KEY_GENERIC_TYPE[][] array, final long index) {
array[segment(index)][displacement(index)]++;
}
/** Decrements the element of the given big array of specified index.
*
* @param array a big array.
* @param index a position in the big array.
*/
public static void decr(final KEY_GENERIC_TYPE[][] array, final long index) {
array[segment(index)][displacement(index)]--;
}
#endif
/** Returns the length of the given big array.
*
* @param array a big array.
* @return the length of the given big array.
*/
public static KEY_GENERIC long length(final KEY_GENERIC_TYPE[][] array) {
final int length = array.length;
return length == 0 ? 0 : start(length - 1) + array[length - 1].length;
}
/** Copies a big array from the specified source big array, beginning at the specified position, to the specified position of the destination big array.
* Handles correctly overlapping regions of the same big array.
*
* @param srcArray the source big array.
* @param srcPos the starting position in the source big array.
* @param destArray the destination big array.
* @param destPos the starting position in the destination data.
* @param length the number of elements to be copied.
*/
public static KEY_GENERIC void copy(final KEY_GENERIC_TYPE[][] srcArray, final long srcPos, final KEY_GENERIC_TYPE[][] destArray, final long destPos, long length) {
if (destPos <= srcPos) {
int srcSegment = segment(srcPos);
int destSegment = segment(destPos);
int srcDispl = displacement(srcPos);
int destDispl = displacement(destPos);
int l;
while(length > 0) {
l = (int)Math.min(length, Math.min(srcArray[srcSegment].length - srcDispl, destArray[destSegment].length - destDispl));
System.arraycopy(srcArray[srcSegment], srcDispl, destArray[destSegment], destDispl, l);
if ((srcDispl += l) == SEGMENT_SIZE) {
srcDispl = 0;
srcSegment++;
}
if ((destDispl += l) == SEGMENT_SIZE) {
destDispl = 0;
destSegment++;
}
length -= l;
}
}
else {
int srcSegment = segment(srcPos + length);
int destSegment = segment(destPos + length);
int srcDispl = displacement(srcPos + length);
int destDispl = displacement(destPos + length);
int l;
while(length > 0) {
if (srcDispl == 0) {
srcDispl = SEGMENT_SIZE;
srcSegment--;
}
if (destDispl == 0) {
destDispl = SEGMENT_SIZE;
destSegment--;
}
l = (int)Math.min(length, Math.min(srcDispl, destDispl));
System.arraycopy(srcArray[srcSegment], srcDispl - l, destArray[destSegment], destDispl - l, l);
srcDispl -= l;
destDispl -= l;
length -= l;
}
}
}
/** Copies a big array from the specified source big array, beginning at the specified position, to the specified position of the destination array.
*
* @param srcArray the source big array.
* @param srcPos the starting position in the source big array.
* @param destArray the destination array.
* @param destPos the starting position in the destination data.
* @param length the number of elements to be copied.
*/
public static KEY_GENERIC void copyFromBig(final KEY_GENERIC_TYPE[][] srcArray, final long srcPos, final KEY_GENERIC_TYPE[] destArray, int destPos, int length) {
int srcSegment = segment(srcPos);
int srcDispl = displacement(srcPos);
int l;
while(length > 0) {
l = Math.min(srcArray[srcSegment].length - srcDispl, length);
System.arraycopy(srcArray[srcSegment], srcDispl, destArray, destPos, l);
if ((srcDispl += l) == SEGMENT_SIZE) {
srcDispl = 0;
srcSegment++;
}
destPos += l;
length -= l;
}
}
/** Copies an array from the specified source array, beginning at the specified position, to the specified position of the destination big array.
*
* @param srcArray the source array.
* @param srcPos the starting position in the source array.
* @param destArray the destination big array.
* @param destPos the starting position in the destination data.
* @param length the number of elements to be copied.
*/
public static KEY_GENERIC void copyToBig(final KEY_GENERIC_TYPE[] srcArray, int srcPos, final KEY_GENERIC_TYPE[][] destArray, final long destPos, long length) {
int destSegment = segment(destPos);
int destDispl = displacement(destPos);
int l;
while(length > 0) {
l = (int)Math.min(destArray[destSegment].length - destDispl, length);
System.arraycopy(srcArray, srcPos, destArray[destSegment], destDispl, l);
if ((destDispl += l) == SEGMENT_SIZE) {
destDispl = 0;
destSegment++;
}
srcPos += l;
length -= l;
}
}
#if KEY_CLASS_Object
/** Creates a new big array using the given one as prototype.
*
*
This method returns a new big array of the given length whose element
* are of the same class as of those of prototype. In case
* of an empty big array, it tries to return {@link #EMPTY_BIG_ARRAY}, if possible.
*
* @param prototype a big array that will be used to type the new one.
* @param length the length of the new big array.
* @return a new big array of given type and length.
*/
SUPPRESS_WARNINGS_KEY_UNCHECKED
public static K[][] newBigArray(final K[][] prototype, final long length) {
return (K[][])newBigArray(prototype.getClass().getComponentType(), length);
}
/** Creates a new big array using a the given one as component type.
*
* This method returns a new big array whose segments
* are of class componentType. In case
* of an empty big array, it tries to return {@link #EMPTY_BIG_ARRAY}, if possible.
*
* @param componentType a class representing the type of segments of the array to be created.
* @param length the length of the new big array.
* @return a new big array of given type and length.
*/
private static Object[][] newBigArray(Class componentType, final long length) {
if (length == 0 && componentType == Object[].class) return EMPTY_BIG_ARRAY;
ensureLength(length);
final int baseLength = (int)((length + SEGMENT_MASK) >>> SEGMENT_SHIFT);
Object[][] base = (Object[][])java.lang.reflect.Array.newInstance(componentType, baseLength);
final int residual = (int)(length & SEGMENT_MASK);
if (residual != 0) {
for(int i = 0; i < baseLength - 1; i++) base[i] = (Object[])java.lang.reflect.Array.newInstance(componentType.getComponentType(), SEGMENT_SIZE);
base[baseLength - 1] = (Object[])java.lang.reflect.Array.newInstance(componentType.getComponentType(), residual);
}
else for(int i = 0; i < baseLength; i++) base[i] = (Object[])java.lang.reflect.Array.newInstance(componentType.getComponentType(), SEGMENT_SIZE);
return base;
}
#endif
/** Creates a new big array.
*
* @param length the length of the new big array.
* @return a new big array of given length.
*/
public static KEY_TYPE[][] newBigArray(final long length) {
if (length == 0) return EMPTY_BIG_ARRAY;
ensureLength(length);
final int baseLength = (int)((length + SEGMENT_MASK) >>> SEGMENT_SHIFT);
KEY_TYPE[][] base = new KEY_TYPE[baseLength][];
final int residual = (int)(length & SEGMENT_MASK);
if (residual != 0) {
for(int i = 0; i < baseLength - 1; i++) base[i] = new KEY_TYPE[SEGMENT_SIZE];
base[baseLength - 1] = new KEY_TYPE[residual];
}
else for(int i = 0; i < baseLength; i++) base[i] = new KEY_TYPE[SEGMENT_SIZE];
return base;
}
#if KEY_CLASS_Object
/** Turns a standard array into a big array.
*
*
Note that the returned big array might contain as a segment the original array.
*
* @param array an array.
* @return a new big array with the same length and content of array.
*/
SUPPRESS_WARNINGS_KEY_UNCHECKED
public static K[][] wrap(final K[] array) {
if (array.length == 0 && array.getClass() == Object[].class) return KEY_GENERIC_BIG_ARRAY_CAST EMPTY_BIG_ARRAY;
if (array.length <= SEGMENT_SIZE) {
final K[][] bigArray = (K[][])java.lang.reflect.Array.newInstance(array.getClass(), 1);
bigArray[0] = array;
return bigArray;
}
final K[][] bigArray = (K[][])newBigArray(array.getClass(), array.length);
for(int i = 0; i < bigArray.length; i++) System.arraycopy(array, (int)start(i), bigArray[i], 0, bigArray[i].length);
return bigArray;
}
#else
/** Turns a standard array into a big array.
*
* Note that the returned big array might contain as a segment the original array.
*
* @param array an array.
* @return a new big array with the same length and content of array.
*/
public static KEY_TYPE[][] wrap(final KEY_TYPE[] array) {
if (array.length == 0) return EMPTY_BIG_ARRAY;
if (array.length <= SEGMENT_SIZE) return new KEY_TYPE[][] { array };
final KEY_TYPE[][] bigArray = newBigArray(array.length);
for(int i = 0; i < bigArray.length; i++) System.arraycopy(array, (int)start(i), bigArray[i], 0, bigArray[i].length);
return bigArray;
}
#endif
/** Ensures that a big array can contain the given number of entries.
*
*
If you cannot foresee whether this big array will need again to be
* enlarged, you should probably use grow() instead.
*
*
Warning: the returned array might use part of the segments of the original
* array, which must be considered read-only after calling this method.
*
* @param array a big array.
* @param length the new minimum length for this big array.
* @return array, if it contains length entries or more; otherwise,
* a big array with length entries whose first length(array)
* entries are the same as those of array.
*/
public static KEY_GENERIC KEY_GENERIC_TYPE[][] ensureCapacity(final KEY_GENERIC_TYPE[][] array, final long length) {
return ensureCapacity(array, length, length(array));
}
#if KEY_CLASS_Object
/** Ensures that a big array can contain the given number of entries, preserving just a part of the big array.
*
*
This method returns a new big array of the given length whose element
* are of the same class as of those of array.
*
*
Warning: the returned array might use part of the segments of the original
* array, which must be considered read-only after calling this method.
*
* @param array a big array.
* @param length the new minimum length for this big array.
* @param preserve the number of elements of the big array that must be preserved in case a new allocation is necessary.
* @return array, if it can contain length entries or more; otherwise,
* a big array with length entries whose first preserve
* entries are the same as those of array.
*/
SUPPRESS_WARNINGS_KEY_UNCHECKED
public static KEY_GENERIC KEY_GENERIC_TYPE[][] ensureCapacity(final KEY_GENERIC_TYPE[][] array, final long length, final long preserve) {
final long oldLength = length(array);
if (length > oldLength) {
ensureLength(length);
final int valid = array.length - (array.length == 0 || array.length > 0 && array[array.length - 1].length == SEGMENT_SIZE ? 0 : 1);
final int baseLength = (int)((length + SEGMENT_MASK) >>> SEGMENT_SHIFT);
final KEY_GENERIC_TYPE[][] base = Arrays.copyOf(array, baseLength);
final Class componentType = array.getClass().getComponentType();
final int residual = (int)(length & SEGMENT_MASK);
if (residual != 0) {
for(int i = valid; i < baseLength - 1; i++) base[i] = (KEY_GENERIC_TYPE[])java.lang.reflect.Array.newInstance(componentType.getComponentType(), SEGMENT_SIZE);
base[baseLength - 1] = (KEY_GENERIC_TYPE[])java.lang.reflect.Array.newInstance(componentType.getComponentType(), residual);
}
else for(int i = valid; i < baseLength; i++) base[i] = (KEY_GENERIC_TYPE[])java.lang.reflect.Array.newInstance(componentType.getComponentType(), SEGMENT_SIZE);
if (preserve - (valid * (long)SEGMENT_SIZE) > 0) copy(array, valid * (long)SEGMENT_SIZE, base, valid * (long)SEGMENT_SIZE, preserve - (valid * (long)SEGMENT_SIZE));
return base;
}
return array;
}
#else
/** Ensures that a big array can contain the given number of entries, preserving just a part of the big array.
*
*
Warning: the returned array might use part of the segments of the original
* array, which must be considered read-only after calling this method.
*
* @param array a big array.
* @param length the new minimum length for this big array.
* @param preserve the number of elements of the big array that must be preserved in case a new allocation is necessary.
* @return array, if it can contain length entries or more; otherwise,
* a big array with length entries whose first preserve
* entries are the same as those of array.
*/
public static KEY_TYPE[][] ensureCapacity(final KEY_TYPE[][] array, final long length, final long preserve) {
final long oldLength = length(array);
if (length > oldLength) {
ensureLength(length);
final int valid = array.length - (array.length == 0 || array.length > 0 && array[array.length - 1].length == SEGMENT_SIZE ? 0 : 1);
final int baseLength = (int)((length + SEGMENT_MASK) >>> SEGMENT_SHIFT);
final KEY_TYPE[][] base = Arrays.copyOf(array, baseLength);
final int residual = (int)(length & SEGMENT_MASK);
if (residual != 0) {
for(int i = valid; i < baseLength - 1; i++) base[i] = new KEY_TYPE[SEGMENT_SIZE];
base[baseLength - 1] = new KEY_TYPE[residual];
}
else for(int i = valid; i < baseLength; i++) base[i] = new KEY_TYPE[SEGMENT_SIZE];
if (preserve - (valid * (long)SEGMENT_SIZE) > 0) copy(array, valid * (long)SEGMENT_SIZE, base, valid * (long)SEGMENT_SIZE, preserve - (valid * (long)SEGMENT_SIZE));
return base;
}
return array;
}
#endif
/** Grows the given big array to the maximum between the given length and
* the current length multiplied by two, provided that the given
* length is larger than the current length.
*
*
If you want complete control on the big array growth, you
* should probably use ensureCapacity() instead.
*
*
Warning: the returned array might use part of the segments of the original
* array, which must be considered read-only after calling this method.
*
* @param array a big array.
* @param length the new minimum length for this big array.
* @return array, if it can contain length
* entries; otherwise, a big array with
* max(length,length(array)/φ) entries whose first
* length(array) entries are the same as those of array.
* */
public static KEY_GENERIC KEY_GENERIC_TYPE[][] grow(final KEY_GENERIC_TYPE[][] array, final long length) {
final long oldLength = length(array);
return length > oldLength ? grow(array, length, oldLength) : array;
}
/** Grows the given big array to the maximum between the given length and
* the current length multiplied by two, provided that the given
* length is larger than the current length, preserving just a part of the big array.
*
*
If you want complete control on the big array growth, you
* should probably use ensureCapacity() instead.
*
*
Warning: the returned array might use part of the segments of the original
* array, which must be considered read-only after calling this method.
*
* @param array a big array.
* @param length the new minimum length for this big array.
* @param preserve the number of elements of the big array that must be preserved in case a new allocation is necessary.
* @return array, if it can contain length
* entries; otherwise, a big array with
* max(length,length(array)/φ) entries whose first
* preserve entries are the same as those of array.
* */
public static KEY_GENERIC KEY_GENERIC_TYPE[][] grow(final KEY_GENERIC_TYPE[][] array, final long length, final long preserve) {
final long oldLength = length(array);
return length > oldLength ? ensureCapacity(array, Math.max(2 * oldLength, length), preserve) : array;
}
#if KEY_CLASS_Object
/** Trims the given big array to the given length.
*
*
Warning: the returned array might use part of the segments of the original
* array, which must be considered read-only after calling this method.
*
* @param array a big array.
* @param length the new maximum length for the big array.
* @return array, if it contains length
* entries or less; otherwise, a big array with
* length entries whose entries are the same as
* the first length entries of array.
*
*/
public static KEY_GENERIC KEY_GENERIC_TYPE[][] trim(final KEY_GENERIC_TYPE[][] array, final long length) {
ensureLength(length);
final long oldLength = length(array);
if (length >= oldLength) return array;
final int baseLength = (int)((length + SEGMENT_MASK) >>> SEGMENT_SHIFT);
final KEY_GENERIC_TYPE[][] base = Arrays.copyOf(array, baseLength);
final int residual = (int)(length & SEGMENT_MASK);
if (residual != 0) base[baseLength - 1] = ARRAYS.trim(base[baseLength - 1], residual);
return base;
}
#else
/** Trims the given big array to the given length.
*
*
Warning: the returned array might use part of the segments of the original
* array, which must be considered read-only after calling this method.
*
* @param array a big array.
* @param length the new maximum length for the big array.
* @return array, if it contains length
* entries or less; otherwise, a big array with
* length entries whose entries are the same as
* the first length entries of array.
*
*/
public static KEY_GENERIC KEY_GENERIC_TYPE[][] trim(final KEY_GENERIC_TYPE[][] array, final long length) {
ensureLength(length);
final long oldLength = length(array);
if (length >= oldLength) return array;
final int baseLength = (int)((length + SEGMENT_MASK) >>> SEGMENT_SHIFT);
final KEY_TYPE[][] base = Arrays.copyOf(array, baseLength);
final int residual = (int)(length & SEGMENT_MASK);
if (residual != 0) base[baseLength - 1] = ARRAYS.trim(base[baseLength - 1], residual);
return base;
}
#endif
/** Sets the length of the given big array.
*
*
Warning: the returned array might use part of the segments of the original
* array, which must be considered read-only after calling this method.
*
* @param array a big array.
* @param length the new length for the big array.
* @return array, if it contains exactly length
* entries; otherwise, if it contains more than
* length entries, a big array with length entries
* whose entries are the same as the first length entries of
* array; otherwise, a big array with length entries
* whose first length(array) entries are the same as those of
* array.
*
*/
public static KEY_GENERIC KEY_GENERIC_TYPE[][] setLength(final KEY_GENERIC_TYPE[][] array, final long length) {
final long oldLength = length(array);
if (length == oldLength) return array;
if (length < oldLength) return trim(array, length);
return ensureCapacity(array, length);
}
/** Returns a copy of a portion of a big array.
*
* @param array a big array.
* @param offset the first element to copy.
* @param length the number of elements to copy.
* @return a new big array containing length elements of array starting at offset.
*/
public static KEY_GENERIC KEY_GENERIC_TYPE[][] copy(final KEY_GENERIC_TYPE[][] array, final long offset, final long length) {
ensureOffsetLength(array, offset, length);
final KEY_GENERIC_TYPE[][] a =
#if KEY_CLASS_Object
newBigArray(array, length);
#else
newBigArray(length);
#endif
copy(array, offset, a, 0, length);
return a;
}
/** Returns a copy of a big array.
*
* @param array a big array.
* @return a copy of array.
*/
public static KEY_GENERIC KEY_GENERIC_TYPE[][] copy(final KEY_GENERIC_TYPE[][] array) {
final KEY_GENERIC_TYPE[][] base = array.clone();
for(int i = base.length; i-- != 0;) base[i] = array[i].clone();
return base;
}
/** Fills the given big array with the given value.
*
*
This method uses a backward loop. It is significantly faster than the corresponding
* method in {@link java.util.Arrays}.
*
* @param array a big array.
* @param value the new value for all elements of the big array.
*/
public static KEY_GENERIC void fill(final KEY_GENERIC_TYPE[][] array, final KEY_GENERIC_TYPE value) {
for(int i = array.length; i-- != 0;) Arrays.fill(array[i], value);
}
/** Fills a portion of the given big array with the given value.
*
*
If possible (i.e., from is 0) this method uses a
* backward loop. In this case, it is significantly faster than the
* corresponding method in {@link java.util.Arrays}.
*
* @param array a big array.
* @param from the starting index of the portion to fill.
* @param to the end index of the portion to fill.
* @param value the new value for all elements of the specified portion of the big array.
*/
public static KEY_GENERIC void fill(final KEY_GENERIC_TYPE[][] array, final long from, long to, final KEY_GENERIC_TYPE value) {
final long length = length(array);
BigArrays.ensureFromTo(length, from, to);
int fromSegment = segment(from);
int toSegment = segment(to);
int fromDispl = displacement(from);
int toDispl = displacement(to);
if (fromSegment == toSegment) {
Arrays.fill(array[fromSegment], fromDispl, toDispl, value);
return;
}
if (toDispl != 0) Arrays.fill(array[toSegment], 0, toDispl, value);
while(--toSegment > fromSegment) Arrays.fill(array[toSegment], value);
Arrays.fill(array[fromSegment], fromDispl, SEGMENT_SIZE, value);
}
/** Returns true if the two big arrays are elementwise equal.
*
*
This method uses a backward loop. It is significantly faster than the corresponding
* method in {@link java.util.Arrays}.
*
* @param a1 a big array.
* @param a2 another big array.
* @return true if the two big arrays are of the same length, and their elements are equal.
*/
public static KEY_GENERIC boolean equals(final KEY_GENERIC_TYPE[][] a1, final KEY_GENERIC_TYPE a2[][]) {
if (length(a1) != length(a2)) return false;
int i = a1.length, j;
KEY_GENERIC_TYPE[] t, u;
while(i-- != 0) {
t = a1[i];
u = a2[i];
j = t.length;
while(j-- != 0) if (! KEY_EQUALS(t[j], u[j])) return false;
}
return true;
}
/* Returns a string representation of the contents of the specified big array.
*
* The string representation consists of a list of the big array's elements, enclosed in square brackets ("[]"). Adjacent elements are separated by the characters ", " (a comma followed by a space). Returns "null" if a is null.
* @param a the big array whose string representation to return.
* @return the string representation of a.
*/
public static KEY_GENERIC String toString(final KEY_GENERIC_TYPE[][] a) {
if (a == null) return "null";
final long last = length(a) - 1;
if (last == - 1) return "[]";
final StringBuilder b = new StringBuilder();
b.append('[');
for (long i = 0; ; i++) {
b.append(String.valueOf(get(a, i)));
if (i == last) return b.append(']').toString();
b.append(", ");
}
}
/** Ensures that a range given by its first (inclusive) and last (exclusive) elements fits a big array.
*
*
This method may be used whenever a big array range check is needed.
*
* @param a a big array.
* @param from a start index (inclusive).
* @param to an end index (inclusive).
* @throws IllegalArgumentException if from is greater than to.
* @throws ArrayIndexOutOfBoundsException if from or to are greater than the big array length or negative.
*/
public static KEY_GENERIC void ensureFromTo(final KEY_GENERIC_TYPE[][] a, final long from, final long to) {
BigArrays.ensureFromTo(length(a), from, to);
}
/** Ensures that a range given by an offset and a length fits a big array.
*
*
This method may be used whenever a big array range check is needed.
*
* @param a a big array.
* @param offset a start index.
* @param length a length (the number of elements in the range).
* @throws IllegalArgumentException if length is negative.
* @throws ArrayIndexOutOfBoundsException if offset is negative or offset+length is greater than the big array length.
*/
public static KEY_GENERIC void ensureOffsetLength(final KEY_GENERIC_TYPE[][] a, final long offset, final long length) {
BigArrays.ensureOffsetLength(length(a), offset, length);
}
/** A type-specific content-based hash strategy for big arrays. */
private static final class BigArrayHashStrategy KEY_GENERIC implements Hash.Strategy, java.io.Serializable {
private static final long serialVersionUID = -7046029254386353129L;
public int hashCode(final KEY_GENERIC_TYPE[][] o) {
return java.util.Arrays.deepHashCode(o);
}
public boolean equals(final KEY_GENERIC_TYPE[][] a, final KEY_GENERIC_TYPE[][] b) {
return BIG_ARRAYS.equals(a, b);
}
}
/** A type-specific content-based hash strategy for big arrays.
*
* This hash strategy may be used in custom hash collections whenever keys are
* big arrays, and they must be considered equal by content. This strategy
* will handle {@code null} correctly, and it is serializable.
*/
@SuppressWarnings({"rawtypes"})
public final static Hash.Strategy HASH_STRATEGY = new BigArrayHashStrategy();
private static final int SMALL = 7;
private static final int MEDIUM = 40;
private static KEY_GENERIC void vecSwap(final KEY_GENERIC_TYPE[][] x, long a, long b, final long n) {
for(int i = 0; i < n; i++, a++, b++) swap(x, a, b);
}
private static KEY_GENERIC long med3(final KEY_GENERIC_TYPE x[][], final long a, final long b, final long c, KEY_COMPARATOR KEY_GENERIC comp) {
int ab = comp.compare(get(x, a), get(x, b));
int ac = comp.compare(get(x, a), get(x, c));
int bc = comp.compare(get(x, b), get(x, c));
return (ab < 0 ?
(bc < 0 ? b : ac < 0 ? c : a) :
(bc > 0 ? b : ac > 0 ? c : a));
}
private static KEY_GENERIC void selectionSort(final KEY_GENERIC_TYPE[][] a, final long from, final long to, final KEY_COMPARATOR KEY_GENERIC comp) {
for(long i = from; i < to - 1; i++) {
long m = i;
for(long j = i + 1; j < to; j++) if (comp.compare(BIG_ARRAYS.get(a, j), BIG_ARRAYS.get(a, m)) < 0) m = j;
if (m != i) swap(a, i, m);
}
}
/** Sorts the specified range of elements according to the order induced by the specified
* comparator using quicksort.
*
*
The sorting algorithm is a tuned quicksort adapted from Jon L. Bentley and M. Douglas
* McIlroy, “Engineering a Sort Function”, Software: Practice and Experience, 23(11), pages
* 1249−1265, 1993.
*
* @param x the big array to be sorted.
* @param from the index of the first element (inclusive) to be sorted.
* @param to the index of the last element (exclusive) to be sorted.
* @param comp the comparator to determine the sorting order.
*/
public static KEY_GENERIC void quickSort(final KEY_GENERIC_TYPE[][] x, final long from, final long to, final KEY_COMPARATOR KEY_GENERIC comp) {
final long len = to - from;
// Selection sort on smallest arrays
if (len < SMALL) {
selectionSort(x, from, to, comp);
return;
}
// Choose a partition element, v
long m = from + len / 2; // Small arrays, middle element
if (len > SMALL) {
long l = from;
long n = to - 1;
if (len > MEDIUM) { // Big arrays, pseudomedian of 9
long s = len / 8;
l = med3(x, l, l + s, l + 2 * s, comp);
m = med3(x, m - s, m, m + s, comp);
n = med3(x, n - 2 * s, n - s, n, comp);
}
m = med3(x, l, m, n, comp); // Mid-size, med of 3
}
final KEY_GENERIC_TYPE v = get(x, m);
// Establish Invariant: v* (v)* v*
long a = from, b = a, c = to - 1, d = c;
while(true) {
int comparison;
while (b <= c && (comparison = comp.compare(get(x, b), v)) <= 0) {
if (comparison == 0) swap(x, a++, b);
b++;
}
while (c >= b && (comparison = comp.compare(get(x, c), v)) >=0) {
if (comparison == 0) swap(x, c, d--);
c--;
}
if (b > c) break;
swap(x, b++, c--);
}
// Swap partition elements back to middle
long s, n = to;
s = Math.min(a - from, b - a);
vecSwap(x, from, b - s, s);
s = Math.min(d - c, n - d- 1);
vecSwap(x, b, n - s, s);
// Recursively sort non-partition-elements
if ((s = b - a) > 1) quickSort(x, from, from + s, comp);
if ((s = d - c) > 1) quickSort(x, n - s, n, comp);
}
SUPPRESS_WARNINGS_KEY_UNCHECKED
private static KEY_GENERIC long med3(final KEY_GENERIC_TYPE x[][], final long a, final long b, final long c) {
int ab = KEY_CMP(get(x, a), get(x, b));
int ac = KEY_CMP(get(x, a), get(x, c));
int bc = KEY_CMP(get(x, b), get(x, c));
return (ab < 0 ?
(bc < 0 ? b : ac < 0 ? c : a) :
(bc > 0 ? b : ac > 0 ? c : a));
}
SUPPRESS_WARNINGS_KEY_UNCHECKED
private static KEY_GENERIC void selectionSort(final KEY_GENERIC_TYPE[][] a, final long from, final long to) {
for(long i = from; i < to - 1; i++) {
long m = i;
for(long j = i + 1; j < to; j++) if (KEY_LESS(BIG_ARRAYS.get(a, j), BIG_ARRAYS.get(a, m))) m = j;
if (m != i) swap(a, i, m);
}
}
/** Sorts the specified big array according to the order induced by the specified
* comparator using quicksort.
*
* The sorting algorithm is a tuned quicksort adapted from Jon L. Bentley and M. Douglas
* McIlroy, “Engineering a Sort Function”, Software: Practice and Experience, 23(11), pages
* 1249−1265, 1993.
*
* @param x the big array to be sorted.
* @param comp the comparator to determine the sorting order.
*
*/
public static KEY_GENERIC void quickSort(final KEY_GENERIC_TYPE[][] x, final KEY_COMPARATOR KEY_GENERIC comp) {
quickSort(x, 0, BIG_ARRAYS.length(x), comp);
}
/** Sorts the specified range of elements according to the natural ascending order using quicksort.
*
*
The sorting algorithm is a tuned quicksort adapted from Jon L. Bentley and M. Douglas
* McIlroy, “Engineering a Sort Function”, Software: Practice and Experience, 23(11), pages
* 1249−1265, 1993.
*
* @param x the big array to be sorted.
* @param from the index of the first element (inclusive) to be sorted.
* @param to the index of the last element (exclusive) to be sorted.
*/
SUPPRESS_WARNINGS_KEY_UNCHECKED
public static KEY_GENERIC void quickSort(final KEY_GENERIC_TYPE[][] x, final long from, final long to) {
final long len = to - from;
// Selection sort on smallest arrays
if (len < SMALL) {
selectionSort(x, from, to);
return;
}
// Choose a partition element, v
long m = from + len / 2; // Small arrays, middle element
if (len > SMALL) {
long l = from;
long n = to - 1;
if (len > MEDIUM) { // Big arrays, pseudomedian of 9
long s = len / 8;
l = med3(x, l, l + s, l + 2 * s);
m = med3(x, m - s, m, m + s);
n = med3(x, n - 2 * s, n - s, n);
}
m = med3(x, l, m, n); // Mid-size, med of 3
}
final KEY_GENERIC_TYPE v = get(x, m);
// Establish Invariant: v* (v)* v*
long a = from, b = a, c = to - 1, d = c;
while(true) {
int comparison;
while (b <= c && (comparison = KEY_CMP(get(x, b), v)) <= 0) {
if (comparison == 0) swap(x, a++, b);
b++;
}
while (c >= b && (comparison = KEY_CMP(get(x, c), v)) >=0) {
if (comparison == 0) swap(x, c, d--);
c--;
}
if (b > c) break;
swap(x, b++, c--);
}
// Swap partition elements back to middle
long s, n = to;
s = Math.min(a - from, b - a);
vecSwap(x, from, b - s, s);
s = Math.min(d - c, n - d- 1);
vecSwap(x, b, n - s, s);
// Recursively sort non-partition-elements
if ((s = b - a) > 1) quickSort(x, from, from + s);
if ((s = d - c) > 1) quickSort(x, n - s, n);
}
/** Sorts the specified big array according to the natural ascending order using quicksort.
*
* The sorting algorithm is a tuned quicksort adapted from Jon L. Bentley and M. Douglas
* McIlroy, “Engineering a Sort Function”, Software: Practice and Experience, 23(11), pages
* 1249−1265, 1993.
*
* @param x the big array to be sorted.
*/
public static KEY_GENERIC void quickSort(final KEY_GENERIC_TYPE[][] x) {
quickSort(x, 0, BIG_ARRAYS.length(x));
}
#if ! KEY_CLASS_Boolean
/**
* Searches a range of the specified big array for the specified value using
* the binary search algorithm. The range must be sorted prior to making this call.
* If it is not sorted, the results are undefined. If the range contains multiple elements with
* the specified value, there is no guarantee which one will be found.
*
* @param a the big array to be searched.
* @param from the index of the first element (inclusive) to be searched.
* @param to the index of the last element (exclusive) to be searched.
* @param key the value to be searched for.
* @return index of the search key, if it is contained in the big array;
* otherwise, (-(insertion point) - 1). The insertion
* point is defined as the the point at which the value would
* be inserted into the big array: the index of the first
* element greater than the key, or the length of the big array, if all
* elements in the big array are less than the specified key. Note
* that this guarantees that the return value will be >= 0 if
* and only if the key is found.
* @see java.util.Arrays
*/
SUPPRESS_WARNINGS_KEY_UNCHECKED
public static KEY_GENERIC long binarySearch(final KEY_GENERIC_TYPE[][] a, long from, long to, final KEY_GENERIC_TYPE key) {
KEY_GENERIC_TYPE midVal;
to--;
while (from <= to) {
final long mid = (from + to) >>> 1;
midVal = get(a, mid);
#if KEYS_PRIMITIVE
if (midVal < key) from = mid + 1;
else if (midVal > key) to = mid - 1;
else return mid;
#else
final int cmp = ((Comparable KEY_SUPER_GENERIC)midVal).compareTo(key);
if (cmp < 0) from = mid + 1;
else if (cmp > 0) to = mid - 1;
else return mid;
#endif
}
return -(from + 1);
}
/**
* Searches a big array for the specified value using
* the binary search algorithm. The range must be sorted prior to making this call.
* If it is not sorted, the results are undefined. If the range contains multiple elements with
* the specified value, there is no guarantee which one will be found.
*
* @param a the big array to be searched.
* @param key the value to be searched for.
* @return index of the search key, if it is contained in the big array;
* otherwise, (-(insertion point) - 1). The insertion
* point is defined as the the point at which the value would
* be inserted into the big array: the index of the first
* element greater than the key, or the length of the big array, if all
* elements in the big array are less than the specified key. Note
* that this guarantees that the return value will be >= 0 if
* and only if the key is found.
* @see java.util.Arrays
*/
public static KEY_GENERIC long binarySearch(final KEY_GENERIC_TYPE[][] a, final KEY_TYPE key) {
return binarySearch(a, 0, BIG_ARRAYS.length(a), key);
}
/**
* Searches a range of the specified big array for the specified value using
* the binary search algorithm and a specified comparator. The range must be sorted following the comparator prior to making this call.
* If it is not sorted, the results are undefined. If the range contains multiple elements with
* the specified value, there is no guarantee which one will be found.
*
* @param a the big array to be searched.
* @param from the index of the first element (inclusive) to be searched.
* @param to the index of the last element (exclusive) to be searched.
* @param key the value to be searched for.
* @param c a comparator.
* @return index of the search key, if it is contained in the big array;
* otherwise, (-(insertion point) - 1). The insertion
* point is defined as the the point at which the value would
* be inserted into the big array: the index of the first
* element greater than the key, or the length of the big array, if all
* elements in the big array are less than the specified key. Note
* that this guarantees that the return value will be >= 0 if
* and only if the key is found.
* @see java.util.Arrays
*/
public static KEY_GENERIC long binarySearch(final KEY_GENERIC_TYPE[][] a, long from, long to, final KEY_GENERIC_TYPE key, final KEY_COMPARATOR KEY_GENERIC c) {
KEY_GENERIC_TYPE midVal;
to--;
while (from <= to) {
final long mid = (from + to) >>> 1;
midVal = get(a, mid);
final int cmp = c.compare(midVal, key);
if (cmp < 0) from = mid + 1;
else if (cmp > 0) to = mid - 1;
else return mid; // key found
}
return -(from + 1);
}
/**
* Searches a big array for the specified value using
* the binary search algorithm and a specified comparator. The range must be sorted following the comparator prior to making this call.
* If it is not sorted, the results are undefined. If the range contains multiple elements with
* the specified value, there is no guarantee which one will be found.
*
* @param a the big array to be searched.
* @param key the value to be searched for.
* @param c a comparator.
* @return index of the search key, if it is contained in the big array;
* otherwise, (-(insertion point) - 1). The insertion
* point is defined as the the point at which the value would
* be inserted into the big array: the index of the first
* element greater than the key, or the length of the big array, if all
* elements in the big array are less than the specified key. Note
* that this guarantees that the return value will be >= 0 if
* and only if the key is found.
* @see java.util.Arrays
*/
public static KEY_GENERIC long binarySearch(final KEY_GENERIC_TYPE[][] a, final KEY_GENERIC_TYPE key, final KEY_COMPARATOR KEY_GENERIC c) {
return binarySearch(a, 0, BIG_ARRAYS.length(a), key, c);
}
#if KEYS_PRIMITIVE
/** The size of a digit used during radix sort (must be a power of 2). */
private static final int DIGIT_BITS = 8;
/** The mask to extract a digit of {@link #DIGIT_BITS} bits. */
private static final int DIGIT_MASK = (1 << DIGIT_BITS) - 1;
/** The number of digits per element. */
private static final int DIGITS_PER_ELEMENT = KEY_CLASS.SIZE / DIGIT_BITS;
/** This method fixes negative numbers so that the combination exponent/significand is lexicographically sorted. */
#if KEY_CLASS_Double
private static final long fixDouble(final double d) {
final long l = Double.doubleToRawLongBits(d);
return l >= 0 ? l : l ^ 0x7FFFFFFFFFFFFFFFL;
}
#elif KEY_CLASS_Float
private static final long fixFloat(final float f) {
final long i = Float.floatToRawIntBits(f);
return i >= 0 ? i : i ^ 0x7FFFFFFF;
}
#endif
/** Sorts the specified big array using radix sort.
*
*
The sorting algorithm is a tuned radix sort adapted from Peter M. McIlroy, Keith Bostic and M. Douglas
* McIlroy, “Engineering radix sort”, Computing Systems, 6(1), pages 5−27 (1993),
* and further improved using the digit-oracle idea described by
* Juha Kärkkäinen and Tommi Rantala in “Engineering radix sort for strings”,
* String Processing and Information Retrieval, 15th International Symposium, volume 5280 of
* Lecture Notes in Computer Science, pages 3−14, Springer (2008).
*
*
This implementation is significantly faster than quicksort
* already at small sizes (say, more than 10000 elements), but it can only
* sort in ascending order.
* It will allocate a support array of bytes with the same number of elements as the array to be sorted.
*
* @param a the big array to be sorted.
*/
public static void radixSort(final KEY_TYPE[][] a) {
radixSort(a, 0, BIG_ARRAYS.length(a));
}
/** Sorts the specified big array using radix sort.
*
*
The sorting algorithm is a tuned radix sort adapted from Peter M. McIlroy, Keith Bostic and M. Douglas
* McIlroy, “Engineering radix sort”, Computing Systems, 6(1), pages 5−27 (1993),
* and further improved using the digit-oracle idea described by
* Juha Kärkkäinen and Tommi Rantala in “Engineering radix sort for strings”,
* String Processing and Information Retrieval, 15th International Symposium, volume 5280 of
* Lecture Notes in Computer Science, pages 3−14, Springer (2008).
*
*
This implementation is significantly faster than quicksort
* already at small sizes (say, more than 10000 elements), but it can only
* sort in ascending order.
* It will allocate a support array of bytes with the same number of elements as the array to be sorted.
*
* @param a the big array to be sorted.
* @param from the index of the first element (inclusive) to be sorted.
* @param to the index of the last element (exclusive) to be sorted.
*/
public static void radixSort(final KEY_TYPE[][] a, final long from, final long to) {
final int maxLevel = DIGITS_PER_ELEMENT - 1;
final int stackSize = ((1 << DIGIT_BITS) - 1) * (DIGITS_PER_ELEMENT - 1) + 1;
final long[] offsetStack = new long[stackSize];
int offsetPos = 0;
final long[] lengthStack = new long[stackSize];
int lengthPos = 0;
final int[] levelStack = new int[stackSize];
int levelPos = 0;
offsetStack[offsetPos++] = from;
lengthStack[lengthPos++] = to - from;
levelStack[levelPos++] = 0;
final long[] count = new long[1 << DIGIT_BITS];
final long[] pos = new long[1 << DIGIT_BITS];
final byte[][] digit = ByteBigArrays.newBigArray(to - from);
while(offsetPos > 0) {
final long first = offsetStack[--offsetPos];
final long length = lengthStack[--lengthPos];
final int level = levelStack[--levelPos];
#if KEY_CLASS_Character
final int signMask = 0;
#else
final int signMask = level % DIGITS_PER_ELEMENT == 0 ? 1 << DIGIT_BITS - 1 : 0;
#endif
if (length < MEDIUM) {
selectionSort(a, first, first + length);
continue;
}
final int shift = (DIGITS_PER_ELEMENT - 1 - level % DIGITS_PER_ELEMENT) * DIGIT_BITS; // This is the shift that extract the right byte from a key
// Count keys.
for(long i = length; i-- != 0;) ByteBigArrays.set(digit, i, (byte)(((KEY2LEXINT(BIG_ARRAYS.get(a, first + i)) >>> shift) & DIGIT_MASK) ^ signMask));
for(long i = length; i-- != 0;) count[ByteBigArrays.get(digit, i) & 0xFF]++;
// Compute cumulative distribution and push non-singleton keys on stack.
int lastUsed = -1;
long p = 0;
for(int i = 0; i < 1 << DIGIT_BITS; i++) {
if (count[i] != 0) {
lastUsed = i;
if (level < maxLevel && count[i] > 1){
//System.err.println(" Pushing " + new StackEntry(first + pos[i - 1], first + pos[i], level + 1));
offsetStack[offsetPos++] = p + first;
lengthStack[lengthPos++] = count[i];
levelStack[levelPos++] = level + 1;
}
}
pos[i] = (p += count[i]);
}
// When all slots are OK, the last slot is necessarily OK.
final long end = length - count[lastUsed];
count[lastUsed] = 0;
// i moves through the start of each block
int c = -1;
for(long i = 0, d; i < end; i += count[c], count[c] = 0) {
KEY_TYPE t = BIG_ARRAYS.get(a, i +first);
c = ByteBigArrays.get(digit, i) & 0xFF;
while((d = --pos[c]) > i) {
final KEY_TYPE z = t;
final int zz = c;
t = BIG_ARRAYS.get(a, d + first);
c = ByteBigArrays.get(digit, d) & 0xFF;
BIG_ARRAYS.set(a, d + first, z);
ByteBigArrays.set(digit, d, (byte)zz);
}
BIG_ARRAYS.set(a, i + first, t);
}
}
}
private static void selectionSort(final KEY_TYPE[][] a, final KEY_TYPE[][] b, final long from, final long to) {
for(long i = from; i < to - 1; i++) {
long m = i;
for(long j = i + 1; j < to; j++)
if (KEY_LESS(BIG_ARRAYS.get(a, j), BIG_ARRAYS.get(a, m)) || KEY_CMP_EQ(BIG_ARRAYS.get(a, j), BIG_ARRAYS.get(a, m)) && KEY_LESS(BIG_ARRAYS.get(b, j), BIG_ARRAYS.get(b, m))) m = j;
if (m != i) {
KEY_TYPE t = BIG_ARRAYS.get(a, i);
BIG_ARRAYS.set(a, i, BIG_ARRAYS.get(a, m));
BIG_ARRAYS.set(a, m, t);
t = BIG_ARRAYS.get(b, i);
BIG_ARRAYS.set(b, i, BIG_ARRAYS.get(b, m));
BIG_ARRAYS.set(b, m, t);
}
}
}
/** Sorts the specified pair of big arrays lexicographically using radix sort.
*
The sorting algorithm is a tuned radix sort adapted from Peter M. McIlroy, Keith Bostic and M. Douglas
* McIlroy, “Engineering radix sort”, Computing Systems, 6(1), pages 5−27 (1993),
* and further improved using the digit-oracle idea described by
* Juha Kärkkäinen and Tommi Rantala in “Engineering radix sort for strings”,
* String Processing and Information Retrieval, 15th International Symposium, volume 5280 of
* Lecture Notes in Computer Science, pages 3−14, Springer (2008).
*
*
This method implements a lexicographical sorting of the arguments. Pairs of elements
* in the same position in the two provided arrays will be considered a single key, and permuted
* accordingly. In the end, either a[i] < a[i + 1] or a[i] == a[i + 1] and b[i] <= b[i + 1].
*
*
This implementation is significantly faster than quicksort
* already at small sizes (say, more than 10000 elements), but it can only
* sort in ascending order. It will allocate a support array of bytes with the same number of elements as the arrays to be sorted.
*
* @param a the first big array to be sorted.
* @param b the second big array to be sorted.
*/
public static void radixSort(final KEY_TYPE[][] a, final KEY_TYPE[][] b) {
radixSort(a, b, 0, BIG_ARRAYS.length(a));
}
/** Sorts the specified pair of big arrays lexicographically using radix sort.
*
*
The sorting algorithm is a tuned radix sort adapted from Peter M. McIlroy, Keith Bostic and M. Douglas
* McIlroy, “Engineering radix sort”, Computing Systems, 6(1), pages 5−27 (1993),
* and further improved using the digit-oracle idea described by
* Juha Kärkkäinen and Tommi Rantala in “Engineering radix sort for strings”,
* String Processing and Information Retrieval, 15th International Symposium, volume 5280 of
* Lecture Notes in Computer Science, pages 3−14, Springer (2008).
*
*
This method implements a lexicographical sorting of the arguments. Pairs of elements
* in the same position in the two provided arrays will be considered a single key, and permuted
* accordingly. In the end, either a[i] < a[i + 1] or a[i] == a[i + 1] and b[i] <= b[i + 1].
*
*
This implementation is significantly faster than quicksort
* already at small sizes (say, more than 10000 elements), but it can only
* sort in ascending order. It will allocate a support array of bytes with the same number of elements as the arrays to be sorted.
*
* @param a the first big array to be sorted.
* @param b the second big array to be sorted.
* @param from the index of the first element (inclusive) to be sorted.
* @param to the index of the last element (exclusive) to be sorted.
*/
public static void radixSort(final KEY_TYPE[][] a, final KEY_TYPE[][] b, final long from, final long to) {
final int layers = 2;
if (BIG_ARRAYS.length(a) != BIG_ARRAYS.length(b)) throw new IllegalArgumentException("Array size mismatch.");
final int maxLevel = DIGITS_PER_ELEMENT * layers - 1;
final int stackSize = ((1 << DIGIT_BITS) - 1) * (layers * DIGITS_PER_ELEMENT - 1) + 1;
final long[] offsetStack = new long[stackSize];
int offsetPos = 0;
final long[] lengthStack = new long[stackSize];
int lengthPos = 0;
final int[] levelStack = new int[stackSize];
int levelPos = 0;
offsetStack[offsetPos++] = from;
lengthStack[lengthPos++] = to - from;
levelStack[levelPos++] = 0;
final long[] count = new long[1 << DIGIT_BITS];
final long[] pos = new long[1 << DIGIT_BITS];
final byte[][] digit = ByteBigArrays.newBigArray(to - from);
while(offsetPos > 0) {
final long first = offsetStack[--offsetPos];
final long length = lengthStack[--lengthPos];
final int level = levelStack[--levelPos];
#if KEY_CLASS_Character
final int signMask = 0;
#else
final int signMask = level % DIGITS_PER_ELEMENT == 0 ? 1 << DIGIT_BITS - 1 : 0;
#endif
if (length < MEDIUM) {
selectionSort(a, b, first, first + length);
continue;
}
final KEY_TYPE[][] k = level < DIGITS_PER_ELEMENT ? a : b; // This is the key array
final int shift = (DIGITS_PER_ELEMENT - 1 - level % DIGITS_PER_ELEMENT) * DIGIT_BITS; // This is the shift that extract the right byte from a key
// Count keys.
for(long i = length; i-- != 0;) ByteBigArrays.set(digit, i, (byte)(((KEY2LEXINT(BIG_ARRAYS.get(k, first + i)) >>> shift) & DIGIT_MASK) ^ signMask));
for(long i = length; i-- != 0;) count[ByteBigArrays.get(digit, i) & 0xFF]++;
// Compute cumulative distribution and push non-singleton keys on stack.
int lastUsed = -1;
long p = 0;
for(int i = 0; i < 1 << DIGIT_BITS; i++) {
if (count[i] != 0) {
lastUsed = i;
if (level < maxLevel && count[i] > 1){
offsetStack[offsetPos++] = p + first;
lengthStack[lengthPos++] = count[i];
levelStack[levelPos++] = level + 1;
}
}
pos[i] = (p += count[i]);
}
// When all slots are OK, the last slot is necessarily OK.
final long end = length - count[lastUsed];
count[lastUsed] = 0;
// i moves through the start of each block
int c = -1;
for(long i = 0, d; i < end; i += count[c], count[c] = 0) {
KEY_TYPE t = BIG_ARRAYS.get(a, i + first);
KEY_TYPE u = BIG_ARRAYS.get(b, i + first);
c = ByteBigArrays.get(digit, i) & 0xFF;
while((d = --pos[c]) > i) {
KEY_TYPE z = t;
final int zz = c;
t = BIG_ARRAYS.get(a, d + first);
BIG_ARRAYS.set(a, d + first, z);
z = u;
u = BIG_ARRAYS.get(b, d + first);
BIG_ARRAYS.set(b, d + first, z);
c = ByteBigArrays.get(digit, d) & 0xFF;
ByteBigArrays.set(digit, d, (byte)zz);
}
BIG_ARRAYS.set(a, i + first, t);
BIG_ARRAYS.set(b, i + first, u);
}
}
}
#endif
#endif
/** Shuffles the specified big array fragment using the specified pseudorandom number generator.
*
* @param a the big array to be shuffled.
* @param from the index of the first element (inclusive) to be shuffled.
* @param to the index of the last element (exclusive) to be shuffled.
* @param random a pseudorandom number generator (please use a XorShift* generator).
* @return a.
*/
public static KEY_GENERIC KEY_GENERIC_TYPE[][] shuffle(final KEY_GENERIC_TYPE[][] a, final long from, final long to, final Random random) {
for(long i = to - from; i-- != 0;) {
final long p = (random.nextLong() & 0x7FFFFFFFFFFFFFFFL) % (i + 1);
final KEY_GENERIC_TYPE t = get(a, from + i);
set(a, from + i, get(a, from + p));
set(a, from + p, t);
}
return a;
}
/** Shuffles the specified big array using the specified pseudorandom number generator.
*
* @param a the big array to be shuffled.
* @param random a pseudorandom number generator (please use a XorShift* generator).
* @return a.
*/
public static KEY_GENERIC KEY_GENERIC_TYPE[][] shuffle(final KEY_GENERIC_TYPE[][] a, final Random random) {
for(long i = length(a); i-- != 0;) {
final long p = (random.nextLong() & 0x7FFFFFFFFFFFFFFFL) % (i + 1);
final KEY_GENERIC_TYPE t = get(a, i);
set(a, i, get(a, p));
set(a, p, t);
}
return a;
}
#if KEY_CLASS_Integer
#ifdef TEST
private static long seed = System.currentTimeMillis();
private static java.util.Random r = new java.util.Random(seed);
private static KEY_TYPE genKey() {
#if KEY_CLASS_Byte || KEY_CLASS_Short || KEY_CLASS_Character
return (KEY_TYPE)(r.nextInt());
#elif KEYS_PRIMITIVE
return r.NEXT_KEY();
#elif KEY_CLASS_Object
return Integer.toBinaryString(r.nextInt());
#else
return new java.io.Serializable() {};
#endif
}
private static Object[] k, v, nk;
private static KEY_TYPE kt[];
private static KEY_TYPE nkt[];
private static BIG_ARRAY_BIG_LIST topList;
protected static void speedTest(int n, boolean b) {}
protected static void test(int n) {
KEY_TYPE[][] a = BIG_ARRAYS.newBigArray(n);
for(int i = 0; i < n; i++) set(a, i, i);
BIG_ARRAYS.copy(a, 0, a, 1, n - 2);
assert a[0][0] == 0;
for(int i = 0; i < n - 2; i++) assert get(a, i + 1) == i;
for(int i = 0; i < n; i++) set(a, i, i);
BIG_ARRAYS.copy(a, 1, a, 0, n - 1);
for(int i = 0; i < n - 1; i++) assert get(a, i) == i + 1;
for(int i = 0; i < n; i++) set(a, i, i);
KEY_TYPE[] b = new KEY_TYPE[n];
for(int i = 0; i < n; i++) b[i] = i;
assert equals(wrap(b), a);
System.out.println("Test OK");
return;
}
public static void main(String args[]) {
int n = Integer.parseInt(args[1]);
if (args.length > 2) r = new java.util.Random(seed = Long.parseLong(args[2]));
try {
if ("speedTest".equals(args[0]) || "speedComp".equals(args[0])) speedTest(n, "speedComp".equals(args[0]));
else if ("test".equals(args[0])) test(n);
} catch(Throwable e) {
e.printStackTrace(System.err);
System.err.println("seed: " + seed);
}
}
#endif
#endif
}