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Open-source constraint solver.
/*
* This file is part of choco-solver, http://choco-solver.org/
*
* Copyright (c) 2020, IMT Atlantique. All rights reserved.
*
* Licensed under the BSD 4-clause license.
*
* See LICENSE file in the project root for full license information.
*/
package org.chocosolver.util.tools;
import static java.lang.reflect.Array.newInstance;
import gnu.trove.list.array.TIntArrayList;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import java.util.Random;
import java.util.Set;
import org.chocosolver.solver.variables.BoolVar;
import org.chocosolver.solver.variables.IntVar;
/**
* This class contains various methods for manipulating arrays.
*
*
* @author Charles Prud'homme, Jean-Guillaume Fages, Rene Helmke
* @since 17 sept. 2010
*/
public enum ArrayUtils {
;
/**
* Creates an array of ints of consecutive values from lb (inclusive) to ub (inclusive as well),
* i.e. the range [lb, ub],
* For instance: {3,4,...,99,100}
* @param lb first element in the array
* @param ub last element in the array
* @return an array of ints
* @throws NegativeArraySizeException if ubc extracted from matrix array.
* @param array double entry matrix
* @param c index of the column to get
* @return the column c from array, or null if array is null or array.length is null,
* or if c is negative or if array.length < c
*/
@SuppressWarnings({"unchecked", "RedundantCast"})
public static int[] getColumn(final int[][] array, final int c) {
if (array != null && array.length > 0
&& c >= 0 && array[0].length > c) {
int[] res = new int[array.length];
for (int i = 0; i < array.length; i++) {
res[i] = array[i][c];
}
return res;
}
return null;
}
/**
* Returns the column c extracted from matrix array.
* @param array double entry matrix
* @param c index of the column to get
* @return the column c from array, or null if array is null or array.length is null,
* or if c is negative or if array.length < c
*/
@SuppressWarnings({"unchecked", "RedundantCast"})
public static double[] getColumn(final double[][] array, final int c) {
if (array != null && array.length > 0
&& c >= 0 && array[0].length > c) {
double[] res = new double[array.length];
for (int i = 0; i < array.length; i++) {
res[i] = array[i][c];
}
return res;
}
return null;
}
/**
* Returns the column c extracted from matrix array.
* @param array double entry matrix
* @param c index of the column to get
* @param the class of the objects in the input matrix
* @return the column c from array, or null if array is null or array.length is null,
* or if c is negative or if array.length < c
*/
@SuppressWarnings({"unchecked", "RedundantCast"})
public static T[] getColumn(final T[][] array, final int c) {
return getColumn(array, c, (Class) array[0].getClass());
}
/**
* Returns the column c extracted from matrix array.
* @param array double entry matrix
* @param c index of the column to get
* @param newType the class of the copy to be returned
* @param the class of the objects in the input matrix
* @return the column c from array, or null if array is null or array.length is null,
* or if c is negative or if array.length < c
*/
@SuppressWarnings({"unchecked", "RedundantCast"})
public static T[] getColumn(final T[][] array, final int c, Class newType) {
if (array != null && array.length > 0
&& c >= 0 && array[0].length > c) {
T[] res = ((Object) newType == (Object) Object[].class)
? (T[]) new Object[array.length]
: (T[]) newInstance(newType.getComponentType(), array.length);
for (int i = 0; i < array.length; i++) {
res[i] = (T) array[i][c];
}
return res;
}
return null;
}
/**
* Sum the lengths of arrays
* @param arrays list of arrays
* @param the class of the objects in the input array
* @return the sum of lengths of arrays
*/
@SafeVarargs
public static int length(final T[]... arrays) {
int length = 0;
for (T[] array : arrays) {
if (array != null) length += array.length;
}
return length;
}
/**
*
* @param array array of elements
* @param obj element to find
* @param the class of the objects in the input array
* @return true if array contains obj
*/
public static boolean contains(T[] array, T obj) {
for (T elem : array) {
if (elem.equals(obj)) return true;
}
return false;
}
/**
* Returns the element in position index when considering all arrays appended altogether.
* @param index position of the element to return
* @param arrays list of arrays
* @param the class of the objects in the input arrays
* @return the element in position index when considering all arrays appended altogether.
*/
@SafeVarargs
public static T get(int index, final T[]... arrays) {
int shift = index;
for (T[] tab : arrays) {
if (shift < tab.length) {
return tab[shift];
} else {
shift -= tab.length;
}
}
return null;
}
/**
* Returns the element in position index when considering all arrays appended altogether.
* @param index position of the element to return
* @param arrays list of arrays
* @param the class of the objects in the input lists
* @return the element in position index when considering all arrays appended altogether.
*/
@SafeVarargs
public static T get(int index, final List... arrays) {
int shift = index;
for (List tab : arrays) {
if (shift < tab.size()) {
return tab.get(shift);
} else {
shift -= tab.size();
}
}
return null;
}
/**
* Append two Arrays
*
* @param toAppend array of arrays to append
* @return a new Array composed of both given in parameters.
*/
@SuppressWarnings("unchecked")
public static T[] append(T[]... toAppend) {
int total = length(toAppend);
T[] ret = (T[]) newInstance(toAppend.getClass().getComponentType().getComponentType(), total);
int pos = 0;
for (T[] tab : toAppend) {
if (tab != null) {
System.arraycopy(tab, 0, ret, pos, tab.length);
pos += tab.length;
}
}
return ret;
}
/**
* Append two Arrays
*
* @param toAppend array of arrays to append
* @return a new Array composed of both given in parameters.
*/
@SuppressWarnings("unchecked")
public static IntVar[] append(IntVar[]... toAppend) {
int total = length(toAppend);
IntVar[] ret = new IntVar[total];
int pos = 0;
for (IntVar[] tab : toAppend) {
if (tab != null) {
System.arraycopy(tab, 0, ret, pos, tab.length);
pos += tab.length;
}
}
return ret;
}
/**
* Append two Arrays
*
* @param toAppend array of arrays to append
* @return a new Array composed of both given in parameters.
*/
@SuppressWarnings("unchecked")
public static BoolVar[] append(BoolVar[]... toAppend) {
int total = length(toAppend);
BoolVar[] ret = new BoolVar[total];
int pos = 0;
for (BoolVar[] tab : toAppend) {
if (tab != null) {
System.arraycopy(tab, 0, ret, pos, tab.length);
pos += tab.length;
}
}
return ret;
}
/**
* Append elements at the end of another array
*
* @param array array of arrays to append
* @param elements elements to append
* @return a new Array composed of both given in parameters.
*/
@SuppressWarnings("unchecked")
public static T[] concat(T[] array, T... elements) {
return append(array, elements);
}
/**
* Append elements at the end of another array
*
* @param array array of arrays to append
* @param elements elements to append
* @return a new Array composed of both given in parameters.
*/
@SuppressWarnings("unchecked")
public static IntVar[] concat(IntVar[] array, IntVar... elements) {
return append(array, elements);
}
/**
* Append elements at the end of another array
*
* @param array array of arrays to append
* @param elements elements to append
* @return a new Array composed of both given in parameters.
*/
@SuppressWarnings("unchecked")
public static BoolVar[] concat(BoolVar[] array, BoolVar... elements) {
return append(array, elements);
}
/**
* Append int arrays
*
* @param toAppend array of arrays to append
* @return a new Array composed of those given in parameters.
*/
@SuppressWarnings("unchecked")
public static int[] append(int[]... toAppend) {
int total = 0;
for (int[] tab : toAppend) {
if (tab != null) {
total += tab.length;
}
}
int[] ret = new int[total];
int pos = 0;
for (int[] tab : toAppend) {
if (tab != null) {
System.arraycopy(tab, 0, ret, pos, tab.length);
pos += tab.length;
}
}
return ret;
}
/**
* Append elements at the end of another array
*
* @param array array of arrays to append
* @param elements elements to append
* @return a new Array composed of both given in parameters.
*/
@SuppressWarnings("unchecked")
public static int[] concat(int[] array, int... elements) {
return append(array, elements);
}
/**
* Reverse all signs of the a given int table.
*
* @param tab array to inverse
*/
public static void inverseSign(int[] tab) {
for (int i = 0; i < tab.length; i++) {
tab[i] = -tab[i];
}
}
/**
* Turns back to from the elements of tab from the middle position.
* @param tab array to reverse
*/
public static void reverse(int[] tab) {
int tmp;
final int n = tab.length;
for (int i = 0; i < n / 2; i++) {
tmp = tab[i];
tab[i] = tab[n - i - 1];
tab[n - i - 1] = tmp;
}
}
/**
* Turns back to from the elements of tab from the middle position.
* @param tab array to reverse
* @param the class of the objects in the input array
*/
public static void reverse(T[] tab) {
T tmp;
final int n = tab.length - 1;
for (int i = 0; i <= n / 2; i++) {
tmp = tab[i];
tab[i] = tab[n - i];
tab[n - i] = tmp;
}
}
/**
* Permutes elements from tab wrt to permutuation: tab[i] = tab[permutation[i]].
* @param permutation permutation
* @param tab array of ints
* @param the class of the objects in the input array
*/
@SuppressWarnings("unchecked")
public static void permutation(int[] permutation, T[] tab) {
T[] tmp = tab.clone();
for (int i = 0; i < tab.length; i++) {
tab[i] = tmp[permutation[i]];
}
}
/**
* Returns a list composed of elements from array.
* @param array array of elements
* @param the class of the objects in the input array
* @return a list composed of elements from array.
*/
public static List toList(T[] array) {
return Arrays.asList(array);
}
/**
* Returns an array composed of elements from list.
* @param c the class of the copy to be returned
* @param list list of elements
* @param the class of the objects in the input array
* @return an array composed of elements from list.
*/
@SuppressWarnings("unchecked")
public static T[] toArray(Class c, List list) {
// T[] array = (T[])Array.newInstance(c, list.size());
// return list.toArray(array);
return list.toArray((T[]) newInstance(c, list.size()));
}
/**
* Creates an array from vargs elt.
* @param elt elements to put in an array
* @param the class of the objects in the returned array
* @return an array from vargs elt
*/
@SafeVarargs
public static T[] toArray(T... elt) {
return elt;
}
/**
* Creates an array from elements in list.
* @param list elements to put in an array
* @param the class of the objects in the returned array
* @return an array from element in list
*/
public static T[] toArray(List list) {
return toArray(list.get(0).getClass(), list);
}
/**
* Transposes a matrix M[n][m] in a matrix MT[m][n] such that MT[i][j] = M[j][i]
* @param matrix matrix to transpose
* @param the class of the objects in the input matrix
* @return a matrix
*/
@SuppressWarnings("unchecked")
public static T[][] transpose(T[][] matrix) {
T[][] ret = (T[][]) newInstance(matrix.getClass().getComponentType(), matrix[0].length);
for (int i = 0; i < ret.length; i++) {
ret[i] = (T[]) newInstance(matrix[0].getClass().getComponentType(), matrix.length);
}
for (int i = 0; i < matrix.length; i++)
for (int j = 0; j < matrix[i].length; j++)
ret[j][i] = matrix[i][j];
return ret;
}
/**
* Transposes a matrix M[n][m] in a matrix MT[m][n] such that MT[i][j] = M[j][i]
* @param matrix matrix to transpose
* @return a matrix
*/
public static int[][] transpose(int[][] matrix) {
int[][] ret = (int[][]) newInstance(matrix.getClass().getComponentType(), matrix[0].length);
for (int i = 0; i < ret.length; i++) {
ret[i] = (int[]) newInstance(matrix[0].getClass().getComponentType(), matrix.length);
}
for (int i = 0; i < matrix.length; i++)
for (int j = 0; j < matrix[i].length; j++)
ret[j][i] = matrix[i][j];
return ret;
}
/**
* Flattens a matrix M[n][m] in an array F[n*m] such that F[i*n+j] = M[i][j].
* @param matrix matrix to flatten
* @param the class of the objects in the input matrix
* @return a matrix
*/
@SuppressWarnings("unchecked")
public static T[] flatten(T[][] matrix) {
int sz = 0;
for (T[] t : matrix) sz += t.length;
T[] ret = (T[]) newInstance(matrix[0].getClass().getComponentType(), sz);
int k = 0;
for (T[] ta : matrix) {
for (T t : ta)
ret[k++] = t;
}
return ret;
}
/**
* Flattens a matrix M[n][m][p] in an array F[n*m*p] such that F[(i*n*m) + (j*m) + k] = M[i][j][k].
* @param matrix matrix to flatten
* @param the class of the objects in the input matrix
* @return a matrix
*/
@SuppressWarnings("unchecked")
public static T[] flatten(T[][][] matrix) {
List elt = new ArrayList<>();
for (T[][] t : matrix) {
for (T[] tt : t) {
elt.addAll(Arrays.asList(tt));
}
}
T[] ret = (T[]) newInstance(matrix[0][0].getClass().getComponentType(), elt.size());
return elt.toArray(ret);
}
@SuppressWarnings("unchecked")
public static T[] flattenSubMatrix(int iMin, int iLength, int jMin, int jLength, T[][] matrix) {
T[] ret = (T[]) newInstance(matrix[0].getClass().getComponentType(), iLength * jLength);
for (int i = 0, k = 0; i < iLength; i++, k += jLength)
System.arraycopy(matrix[iMin + i], jMin, ret, k, jLength);
return ret;
}
/**
* Flattens a matrix M[n][m] in an array F[n*m] such that F[i*n+j] = M[i][j].
* @param matrix matrix to flatten
* @return a matrix
*/
public static int[] flatten(int[][] matrix) {
int sz = 0;
for (int[] t : matrix) sz += t.length;
final int[] ret = new int[sz];
int k = 0;
for (int[] ta : matrix) {
for (int t : ta)
ret[k++] = t;
}
return ret;
}
public static int[] createNonRedundantSortedValues(TIntArrayList values) {
values.sort();
int offset = 1;
while (offset < values.size()) {
while (values.get(offset - 1) == values.get(offset)) {
values.remove(offset);
if (offset == values.size()) {
break;
}
}
offset++;
}
return values.toArray();
}
/**
* Create an array of elements in set and sort them using {@link Arrays#sort(Object[])}
* @param set set of elements
* @param the class of the objects in the input set.
* @return an array of sorted elements from set
*/
@SuppressWarnings("unchecked")
public static > T[] sort(Set set) {
final LinkedList tmpl = new LinkedList<>(set);
if (tmpl.isEmpty()) {
return null;
} else {
T[] tmpa = (T[]) newInstance(tmpl.getFirst().getClass(), tmpl.size());
tmpl.toArray(tmpa);
Arrays.sort(tmpa);
return tmpa;
}
}
/**
* Duplicates arr and returns the new copy
* @param arr matrix to duplicate
* @return a copy of arr
*/
public static int[][][][] swallowCopy(int[][][][] arr) {
int s0 = arr.length;
int[][][][] copy = new int[s0][][][];
for (int i = s0 - 1; i >= 0; i--) {
int s1 = arr[i].length;
copy[i] = new int[s1][][];
for (int j = s1 - 1; j >= 0; j--) {
int s2 = arr[i][j].length;
copy[i][j] = new int[s2][];
for (int k = s2 - 1; k >= 0; k--) {
int s3 = arr[i][j][k].length;
copy[i][j][k] = new int[s3];
System.arraycopy(arr[i][j][k], 0, copy[i][j][k], 0, s3);
}
}
}
return copy;
}
/**
* Duplicates arr and returns the new copy
* @param arr matrix to duplicate
* @return a copy of arr
*/
public static int[][][] swallowCopy(int[][][] arr) {
int s0 = arr.length;
int[][][] copy = new int[s0][][];
for (int i = s0 - 1; i >= 0; i--) {
int s1 = arr[i].length;
copy[i] = new int[s1][];
for (int j = s1 - 1; j >= 0; j--) {
int s2 = arr[i][j].length;
copy[i][j] = new int[s2];
System.arraycopy(arr[i][j], 0, copy[i][j], 0, s2);
}
}
return copy;
}
/**
* Creates and returns an array of ints composed of unique values from 0 (inclusive) to nb (exclusive), in random order.
* @param nb upper value (exclusive)
* @return an array of ints composed of unique values from 0 (inclusive) to nb (exclusive), in random order.
*/
public static int[] zeroToNShuffle(int nb) {
return zeroToNShuffle(nb, System.nanoTime());
}
/**
* Creates and returns an array of ints composed of unique values from 0 (inclusive) to nb (exclusive), in random order.
* @param nb upper value (exclusive)
* @param seed seed for randomness
* @return an array of ints composed of unique values from 0 (inclusive) to nb (exclusive), in random order.
*/
public static int[] zeroToNShuffle(int nb, long seed) {
Random r = new Random(seed);
int[] ret = new int[nb];
ArrayList tmp = new ArrayList<>();
for (int i = 0; i < nb; i++) tmp.add(i);
Collections.shuffle(tmp);
return tmp.stream().mapToInt(i -> i).toArray();
}
/**
* Permutes randomly elements from tab
* @param tab array of ints
* @param r randomness generator
*/
public static void randomPermutations(int[] tab, Random r) {
int l = tab.length;
for (int i = 0; i < l; i++) {
int j = r.nextInt(l);
int tmp = tab[i];
tab[i] = tab[j];
tab[j] = tmp;
}
}
/**
* Permutes randomly elements from tab
* @param tab array of ints
* @param seed seed for randomness
*/
public static void randomPermutations(int[] tab, long seed) {
randomPermutations(tab, new Random(seed));
}
/**
* Permutes randomly elements from tab
* @param tab array of ints
* @param r randomness generator
* @param the class of the objects in the input array
*/
public static void randomPermutations(E[] tab, Random r) {
int l = tab.length;
for (int i = 0; i < l; i++) {
int j = r.nextInt(l);
E tmp = tab[i];
tab[i] = tab[j];
tab[j] = tmp;
}
}
/**
* Permutes randomly elements from tab
* @param tab array of ints
* @param seed seed for randomness
* @param the class of the objects in the input array
*/
public static void randomPermutations(E[] tab, long seed) {
randomPermutations(tab, new Random(seed));
}
/**
* Adapted from java.util.Arrays#binarySearch0(int[], int, int, int) ,
* it returns the value greater or equal to key in an increasing order value array
* If the key exists in a, it returns the index of key in a,
* otherwise it returns the index of the closest value greater than key when gq is set to true,
* or the index of the closest value smaller than key when gq is set to false.
*
* @param a the values, increasingly ordered
* @param fromIndex starting index (inclusive)
* @param toIndex ending index (exclusive)
* @param key value to look for
* @param gq set to true to look for the value greater or equal to key,
* false to look for the value smaller or equal to the key
*/
public static int binarySearchInc(int[] a, int fromIndex, int toIndex, int key, boolean gq) {
int p = Arrays.binarySearch(a, fromIndex, toIndex, key);
if (p >= 0) {
return p;
} else {
p = -(p + 1);
p -= (gq ? 0 : 1);
return p;
}
}
/**
* Sorts the input array if it is not already sorted,
* and removes multiple occurrences of the same value
*
* @param values array of values
* @return a sorted array containing each value of values exactly once
*/
public static int[] mergeAndSortIfNot(int[] values) {
int n = values.length;
boolean sorted = true;
boolean noDouble = true;
for (int i = 0; i < n - 1 && sorted; i++) {
if (values[i] > values[i + 1]) {
sorted = false;
noDouble = false;// cannot be sure
}
if (values[i] == values[i + 1]) {
noDouble = false;
}
}
if (!sorted) {
Arrays.sort(values);
}
if (!noDouble) {
int nbVals = 1;
for (int i = 0; i < n - 1; i++) {
assert values[i] <= values[i + 1];
if (values[i] < values[i + 1]) {
nbVals++;
}
}
if (nbVals < n) {
int[] correctValues = new int[nbVals];
int idx = 0;
for (int i = 0; i < n - 1; i++) {
if (values[i] < values[i + 1]) {
correctValues[idx++] = values[i];
}
}
correctValues[idx] = values[n - 1];
return correctValues;
}
}
return values;
}
}