package edu.stanford.nlp.util;
import edu.stanford.nlp.util.logging.Redwood;
import java.lang.reflect.Array;
import java.util.*;
import java.util.function.Function;
import java.util.function.Predicate;
/**
* Static utility methods for operating on arrays.
*
* Note: You can also find some methods for printing arrays that are tables in
* StringUtils. (Search for makeTextTable, etc.)
*
* @author Huy Nguyen (htnguyen@cs.stanford.edu)
* @author Michel Galley (mgalley@stanford.edu)
*/
public class ArrayUtils {
/** A logger for this class */
private static Redwood.RedwoodChannels log = Redwood.channels(ArrayUtils.class);
/**
* Should not be instantiated
*/
private ArrayUtils() {}
public static byte[] gapEncode(int[] orig) {
List<Byte> encodedList = gapEncodeList(orig);
byte[] arr = new byte[encodedList.size()];
int i = 0;
for (byte b : encodedList) { arr[i++] = b; }
return arr;
}
public static List<Byte> gapEncodeList(int[] orig) {
for (int i = 1; i < orig.length; i++) {
if (orig[i] < orig[i-1]) {
throw new IllegalArgumentException("Array must be sorted!");
}
}
List<Byte> bytes = new ArrayList<>();
int index = 0;
int prevNum = 0;
byte currByte = 0 << 8;
for (int f : orig) {
String n = (f == prevNum ? "" : Integer.toString(f-prevNum, 2));
for (int ii = 0; ii < n.length(); ii++) {
if (index == 8) {
bytes.add(currByte);
currByte = 0 << 8;
index = 0;
}
currByte <<= 1;
currByte++;
index++;
}
if (index == 8) {
bytes.add(currByte);
currByte = 0 << 8;
index = 0;
}
currByte <<= 1;
index++;
for (int i = 1; i < n.length(); i++) {
if (index == 8) {
bytes.add(currByte);
currByte = 0 << 8;
index = 0;
}
currByte <<= 1;
if (n.charAt(i) == '1') {
currByte++;
}
index++;
}
prevNum = f;
}
while (index > 0 && index < 9) {
if (index == 8) {
bytes.add(currByte);
break;
}
currByte <<= 1;
currByte++;
index++;
}
return bytes;
}
public static int[] gapDecode(byte[] gapEncoded) {
return gapDecode(gapEncoded, 0, gapEncoded.length);
}
public static int[] gapDecode(byte[] gapEncoded, int startIndex, int endIndex) {
List<Integer> ints = gapDecodeList(gapEncoded, startIndex, endIndex);
int[] arr = new int[ints.size()];
int index = 0;
for (int i : ints) { arr[index++] = i; }
return arr;
}
public static List<Integer> gapDecodeList(byte[] gapEncoded) {
return gapDecodeList(gapEncoded, 0, gapEncoded.length);
}
public static List<Integer> gapDecodeList(byte[] gapEncoded, int startIndex, int endIndex) {
boolean gettingSize = true;
int size = 0;
List<Integer> ints = new ArrayList<>();
int gap = 0;
int prevNum = 0;
for (int i = startIndex; i < endIndex; i++) {
byte b = gapEncoded[i];
for (int index = 7; index >= 0; index--) {
boolean value = ((b >> index) & 1) == 1;
if (gettingSize) {
if (value) { size++; }
else {
if (size == 0) {
ints.add(prevNum);
} else if (size == 1) {
prevNum++;
ints.add(prevNum);
size = 0;
} else {
gettingSize = false;
gap = 1;
size--;
}
}
} else {
gap <<= 1;
if (value) { gap++; }
size--;
if (size == 0) {
prevNum += gap;
ints.add(prevNum);
gettingSize = true;
}
}
}
}
return ints;
}
public static byte[] deltaEncode(int[] orig) {
List<Byte> encodedList = deltaEncodeList(orig);
byte[] arr = new byte[encodedList.size()];
int i = 0;
for (byte b : encodedList) { arr[i++] = b; }
return arr;
}
public static List<Byte> deltaEncodeList(int[] orig) {
for (int i = 1; i < orig.length; i++) {
if (orig[i] < orig[i-1]) {
throw new IllegalArgumentException("Array must be sorted!");
}
}
List<Byte> bytes = new ArrayList<>();
int index = 0;
int prevNum = 0;
byte currByte = 0 << 8;
for (int f : orig) {
String n = (f == prevNum ? "" : Integer.toString(f-prevNum, 2));
String n1 = (n.isEmpty() ? "" : Integer.toString(n.length(), 2));
for (int ii = 0; ii < n1.length(); ii++) {
if (index == 8) {
bytes.add(currByte);
currByte = 0 << 8;
index = 0;
}
currByte <<= 1;
currByte++;
index++;
}
if (index == 8) {
bytes.add(currByte);
currByte = 0 << 8;
index = 0;
}
currByte <<= 1;
index++;
for (int i = 1; i < n1.length(); i++) {
if (index == 8) {
bytes.add(currByte);
currByte = 0 << 8;
index = 0;
}
currByte <<= 1;
if (n1.charAt(i) == '1') {
currByte++;
}
index++;
}
for (int i = 1; i < n.length(); i++) {
if (index == 8) {
bytes.add(currByte);
currByte = 0 << 8;
index = 0;
}
currByte <<= 1;
if (n.charAt(i) == '1') {
currByte++;
}
index++;
}
prevNum = f;
}
while (index > 0 && index < 9) {
if (index == 8) {
bytes.add(currByte);
break;
}
currByte <<= 1;
currByte++;
index++;
}
return bytes;
}
public static int[] deltaDecode(byte[] deltaEncoded) {
return deltaDecode(deltaEncoded, 0, deltaEncoded.length);
}
public static int[] deltaDecode(byte[] deltaEncoded, int startIndex, int endIndex) {
List<Integer> ints = deltaDecodeList(deltaEncoded);
int[] arr = new int[ints.size()];
int index = 0;
for (int i : ints) { arr[index++] = i; }
return arr;
}
public static List<Integer> deltaDecodeList(byte[] deltaEncoded) {
return deltaDecodeList(deltaEncoded, 0, deltaEncoded.length);
}
public static List<Integer> deltaDecodeList(byte[] deltaEncoded, int startIndex, int endIndex) {
boolean gettingSize1 = true;
boolean gettingSize2 = false;
int size1 = 0;
List<Integer> ints = new ArrayList<>();
int gap = 0;
int size2 = 0;
int prevNum = 0;
for (int i = startIndex; i < endIndex; i++) {
byte b = deltaEncoded[i];
for (int index = 7; index >= 0; index--) {
boolean value = ((b >> index) & 1) == 1;
if (gettingSize1) {
if (value) { size1++; }
else {
if (size1 == 0) {
ints.add(prevNum);
} else if (size1 == 1) {
prevNum++;
ints.add(prevNum);
size1 = 0;
} else {
gettingSize1 = false;
gettingSize2 = true;
size2 = 1;
size1--;
}
}
} else if (gettingSize2) {
size2 <<= 1;
if (value) { size2++; }
size1--;
if (size1 == 0) {
gettingSize2 = false;
gap = 1;
size2--;
}
} else {
gap <<= 1;
if (value) { gap++; }
size2--;
if (size2 == 0) {
prevNum += gap;
ints.add(prevNum);
gettingSize1 = true;
}
}
}
}
return ints;
}
/** helper for gap encoding. */
private static byte[] bitSetToByteArray(BitSet bitSet) {
while (bitSet.length() % 8 != 0) { bitSet.set(bitSet.length(), true); }
byte[] array = new byte[bitSet.length()/8];
for (int i = 0; i < array.length; i++) {
int offset = i * 8;
int index = 0;
for (int j = 0; j < 8; j++) {
index <<= 1;
if (bitSet.get(offset+j)) { index++; }
}
array[i] = (byte)(index - 128);
}
return array;
}
/** helper for gap encoding. */
private static BitSet byteArrayToBitSet(byte[] array) {
BitSet bitSet = new BitSet();
int index = 0;
for (byte b : array) {
int b1 = ((int)b) + 128;
bitSet.set(index++, ((b1 >> 7) & 1) == 1);
bitSet.set(index++, ((b1 >> 6) & 1) == 1);
bitSet.set(index++, ((b1 >> 5) & 1) == 1);
bitSet.set(index++, ((b1 >> 4) & 1) == 1);
bitSet.set(index++, ((b1 >> 3) & 1) == 1);
bitSet.set(index++, ((b1 >> 2) & 1) == 1);
bitSet.set(index++, ((b1 >> 1) & 1) == 1);
bitSet.set(index++, (b1 & 1) == 1);
}
return bitSet;
}
// for (int i = 1; i < orig.length; i++) {
// if (orig[i] < orig[i-1]) { throw new RuntimeException("Array must be sorted!"); }
// StringBuilder bits = new StringBuilder();
// int prevNum = 0;
// for (int f : orig) {
// StringBuilder bits1 = new StringBuilder();
// log.info(f+"\t");
// String n = Integer.toString(f-prevNum, 2);
// String n1 = Integer.toString(n.length(), 2);
// for (int ii = 0; ii < n1.length(); ii++) {
// bits1.append("1");
// }
// bits1.append("0");
// bits1.append(n1.substring(1));
// bits1.append(n.substring(1));
// log.info(bits1+"\t");
// bits.append(bits1);
// prevNum = f;
// }
public static double[] flatten(double[][] array) {
int size = 0;
for (double[] a : array) {
size += a.length;
}
double[] newArray = new double[size];
int i = 0;
for (double[] a : array) {
for (double d : a) {
newArray[i++] = d;
}
}
return newArray;
}
public static double[][] to2D(double[] array, int dim1Size) {
int dim2Size = array.length/dim1Size;
return to2D(array, dim1Size, dim2Size);
}
public static double[][] to2D(double[] array, int dim1Size, int dim2Size) {
double[][] newArray = new double[dim1Size][dim2Size];
int k = 0;
for (int i = 0; i < newArray.length; i++) {
for (int j = 0; j < newArray[i].length; j++) {
newArray[i][j] = array[k++];
}
}
return newArray;
}
/**
* Removes the element at the specified index from the array, and returns
* a new array containing the remaining elements. If <tt>index</tt> is
* invalid, returns <tt>array</tt> unchanged.
*/
public static double[] removeAt(double[] array, int index) {
if (array == null) {
return null;
}
if (index < 0 || index >= array.length) {
return array;
}
double[] retVal = new double[array.length - 1];
for (int i = 0; i < array.length; i++) {
if (i < index) {
retVal[i] = array[i];
} else if (i > index) {
retVal[i - 1] = array[i];
}
}
return retVal;
}
/**
* Removes the element at the specified index from the array, and returns
* a new array containing the remaining elements. If <tt>index</tt> is
* invalid, returns <tt>array</tt> unchanged. Uses reflection to determine
* the type of the array and returns an array of the appropriate type.
*/
public static Object[] removeAt(Object[] array, int index) {
if (array == null) {
return null;
}
if (index < 0 || index >= array.length) {
return array;
}
Object[] retVal = (Object[]) Array.newInstance(array[0].getClass(), array.length - 1);
for (int i = 0; i < array.length; i++) {
if (i < index) {
retVal[i] = array[i];
} else if (i > index) {
retVal[i - 1] = array[i];
}
}
return retVal;
}
public static String toString(int[][] a) {
StringBuilder result = new StringBuilder("[");
for (int i = 0; i < a.length; i++) {
result.append(Arrays.toString(a[i]));
if(i < a.length-1)
result.append(',');
}
result.append(']');
return result.toString();
}
/**
* Tests two int[][] arrays for having equal contents.
* @return true iff for each i, <code>equalContents(xs[i],ys[i])</code> is true
*/
public static boolean equalContents(int[][] xs, int[][] ys) {
if(xs ==null)
return ys == null;
if(ys == null)
return false;
if(xs.length != ys.length)
return false;
for(int i = xs.length-1; i >= 0; i--) {
if(! equalContents(xs[i],ys[i]))
return false;
}
return true;
}
/**
* Tests two double[][] arrays for having equal contents.
* @return true iff for each i, <code>equals(xs[i],ys[i])</code> is true
*/
public static boolean equals(double[][] xs, double[][] ys) {
if(xs == null)
return ys == null;
if(ys == null)
return false;
if(xs.length != ys.length)
return false;
for(int i = xs.length-1; i >= 0; i--) {
if(!Arrays.equals(xs[i],ys[i]))
return false;
}
return true;
}
/**
* tests two int[] arrays for having equal contents
* @return true iff xs and ys have equal length, and for each i, <code>xs[i]==ys[i]</code>
*/
public static boolean equalContents(int[] xs, int[] ys) {
if(xs.length != ys.length)
return false;
for(int i = xs.length-1; i >= 0; i--) {
if(xs[i] != ys[i])
return false;
}
return true;
}
/**
* Tests two boolean[][] arrays for having equal contents.
* @return true iff for each i, <code>Arrays.equals(xs[i],ys[i])</code> is true
*/
@SuppressWarnings("null")
public static boolean equals(boolean[][] xs, boolean[][] ys) {
if(xs == null && ys != null)
return false;
if(ys == null)
return false;
if(xs.length != ys.length)
return false;
for(int i = xs.length-1; i >= 0; i--) {
if(! Arrays.equals(xs[i],ys[i]))
return false;
}
return true;
}
/** Returns true iff object o equals (not ==) some element of array a. */
public static <T> boolean contains(T[] a, T o) {
for (T item : a) {
if (item.equals(o)) return true;
}
return false;
}
// from stackoverflow
// http://stackoverflow.com/questions/80476/how-to-concatenate-two-arrays-in-java
/**
* Concatenates two arrays and returns the result
*/
public static <T> T[] concatenate(T[] first, T[] second) {
T[] result = Arrays.copyOf(first, first.length + second.length);
System.arraycopy(second, 0, result, first.length, second.length);
return result;
}
/**
* Returns an array with only the elements accepted by <code>filter</code>
* <br>
* Implementation notes: creates two arrays, calls <code>filter</code>
* once for each element, does not alter <code>original</code>
*/
public static <T> T[] filter(T[] original, Predicate<? super T> filter) {
T[] result = Arrays.copyOf(original, original.length); // avoids generic array creation compile error
int size = 0;
for (T value : original) {
if (filter.test(value)) {
result[size] = value;
size++;
}
}
if (size == original.length) {
return result;
}
return Arrays.copyOf(result, size);
}
/** Return a Set containing the same elements as the specified array.
*/
public static <T> Set<T> asSet(T[] a) {
return Generics.newHashSet(Arrays.asList(a));
}
/** Return an immutable Set containing the same elements as the specified
* array. Arrays with 0 or 1 elements are special cased to return the
* efficient small sets from the Collections class.
*/
public static <T> Set<T> asImmutableSet(T[] a) {
if (a.length == 0) {
return Collections.emptySet();
} else if (a.length == 1) {
return Collections.singleton(a[0]);
} else {
return Collections.unmodifiableSet(Generics.newHashSet(Arrays.asList(a)));
}
}
public static void fill(double[][] d, double val) {
for (double[] aD : d) {
Arrays.fill(aD, val);
}
}
public static void fill(double[][][] d, double val) {
for (double[][] aD : d) {
fill(aD, val);
}
}
public static void fill(double[][][][] d, double val) {
for (double[][][] aD : d) {
fill(aD, val);
}
}
public static void fill(boolean[][] d, boolean val) {
for (boolean[] aD : d) {
Arrays.fill(aD, val);
}
}
public static void fill(boolean[][][] d, boolean val) {
for (boolean[][] aD : d) {
fill(aD, val);
}
}
public static void fill(boolean[][][][] d, boolean val) {
for (boolean[][][] aD : d) {
fill(aD, val);
}
}
/**
* Casts to a double array
*/
public static double[] toDouble(float[] a) {
double[] d = new double[a.length];
for (int i = 0; i < a.length; i++) {
d[i] = a[i];
}
return d;
}
/**
* Casts to a double array.
*/
public static double[] toDouble(int[] array) {
double[] rv = new double[array.length];
for (int i = 0; i < array.length; i++) {
rv[i] = array[i];
}
return rv;
}
/** needed because Arrays.asList() won't to autoboxing,
* so if you give it a primitive array you get a
* singleton list back with just that array as an element.
*/
public static List<Integer> asList(int[] array) {
List<Integer> l = new ArrayList<>();
for (int i : array) {
l.add(i);
}
return l;
}
public static double[] asPrimitiveDoubleArray(Collection<Double> d) {
double[] newD = new double[d.size()];
int i = 0;
for (Double j : d) {
newD[i++] = j;
}
return newD;
}
public static int[] asPrimitiveIntArray(Collection<Integer> d) {
int[] newI = new int[d.size()];
int i = 0;
for (Integer j : d) {
newI[i++] = j;
}
return newI;
}
public static long[] copy(long[] arr) {
if (arr == null) { return null; }
long[] newArr = new long[arr.length];
System.arraycopy(arr, 0, newArr, 0, arr.length);
return newArr;
}
public static int[] copy(int[] i) {
if (i == null) { return null; }
int[] newI = new int[i.length];
System.arraycopy(i, 0, newI, 0, i.length);
return newI;
}
public static int[][] copy(int[][] i) {
if (i == null) { return null; }
int[][] newI = new int[i.length][];
for (int j = 0; j < newI.length; j++) {
newI[j] = copy(i[j]);
}
return newI;
}
public static double[] copy(double[] d) {
if (d == null) { return null; }
double[] newD = new double[d.length];
System.arraycopy(d, 0, newD, 0, d.length);
return newD;
}
public static double[][] copy(double[][] d) {
if (d == null) { return null; }
double[][] newD = new double[d.length][];
for (int i = 0; i < newD.length; i++) {
newD[i] = copy(d[i]);
}
return newD;
}
public static double[][][] copy(double[][][] d) {
if (d == null) { return null; }
double[][][] newD = new double[d.length][][];
for (int i = 0; i < newD.length; i++) {
newD[i] = copy(d[i]);
}
return newD;
}
public static float[] copy(float[] d) {
if (d == null) { return null; }
float[] newD = new float[d.length];
System.arraycopy(d, 0, newD, 0, d.length);
return newD;
}
public static float[][] copy(float[][] d) {
if (d == null) { return null; }
float[][] newD = new float[d.length][];
for (int i = 0; i < newD.length; i++) {
newD[i] = copy(d[i]);
}
return newD;
}
public static float[][][] copy(float[][][] d) {
if (d == null) { return null; }
float[][][] newD = new float[d.length][][];
for (int i = 0; i < newD.length; i++) {
newD[i] = copy(d[i]);
}
return newD;
}
public static String toString(double[][] b) {
StringBuilder result = new StringBuilder("[");
for (int i = 0; i < b.length; i++) {
result.append(Arrays.toString(b[i]));
if(i < b.length-1)
result.append(',');
}
result.append(']');
return result.toString();
}
public static String toString(boolean[][] b) {
StringBuilder result = new StringBuilder("[");
for (int i = 0; i < b.length; i++) {
result.append(Arrays.toString(b[i]));
if(i < b.length-1)
result.append(',');
}
result.append(']');
return result.toString();
}
public static long[] toPrimitive(Long[] in) {
return toPrimitive(in,0L);
}
public static int[] toPrimitive(Integer[] in) {
return toPrimitive(in,0);
}
public static short[] toPrimitive(Short[] in) {
return toPrimitive(in,(short)0);
}
public static char[] toPrimitive(Character[] in) {
return toPrimitive(in,(char)0);
}
public static double[] toPrimitive(Double[] in) {
return toPrimitive(in,0.0);
}
public static long[] toPrimitive(Long[] in, long valueForNull) {
if (in == null)
return null;
final long[] out = new long[in.length];
for (int i = 0; i < in.length; i++) {
Long b = in[i];
out[i] = (b == null ? valueForNull : b);
}
return out;
}
public static int[] toPrimitive(Integer[] in, int valueForNull) {
if (in == null)
return null;
final int[] out = new int[in.length];
for (int i = 0; i < in.length; i++) {
Integer b = in[i];
out[i] = (b == null ? valueForNull : b);
}
return out;
}
public static short[] toPrimitive(Short[] in, short valueForNull) {
if (in == null)
return null;
final short[] out = new short[in.length];
for (int i = 0; i < in.length; i++) {
Short b = in[i];
out[i] = (b == null ? valueForNull : b);
}
return out;
}
public static char[] toPrimitive(Character[] in, char valueForNull) {
if (in == null)
return null;
final char[] out = new char[in.length];
for (int i = 0; i < in.length; i++) {
Character b = in[i];
out[i] = (b == null ? valueForNull : b);
}
return out;
}
public static double[] toDoubleArray(String[] in) {
double[] ret = new double[in.length];
for (int i = 0; i < in.length; i++)
ret[i] = Double.parseDouble(in[i]);
return ret;
}
public static double[] toPrimitive(Double[] in, double valueForNull) {
if (in == null)
return null;
final double[] out = new double[in.length];
for (int i = 0; i < in.length; i++) {
Double b = in[i];
out[i] = (b == null ? valueForNull : b);
}
return out;
}
/**
* Provides a consistent ordering over arrays. First compares by the
* first element. If that element is equal, the next element is
* considered, and so on. This is the array version of
* {@link edu.stanford.nlp.util.CollectionUtils#compareLists}
* and uses the same logic when the arrays are of different lengths.
*/
public static <T extends Comparable<T>> int compareArrays(T[] first, T[] second) {
List<T> firstAsList = Arrays.asList(first);
List<T> secondAsList = Arrays.asList(second);
return CollectionUtils.compareLists(firstAsList, secondAsList);
}
/* -- This is an older more direct implementation of the above, but not necessary unless for performance
public static <C extends Comparable<C>> int compareArrays(C[] a1, C[] a2) {
int len = Math.min(a1.length, a2.length);
for (int i = 0; i < len; i++) {
int comparison = a1[i].compareTo(a2[i]);
if (comparison != 0) return comparison;
}
// one is a prefix of the other, or they're identical
if (a1.length < a2.length) return -1;
if (a1.length > a2.length) return 1;
return 0;
}
*/
public static List<Integer> getSubListIndex(Object[] tofind, Object[] tokens){
return getSubListIndex(tofind, tokens, (o1) -> o1.first().equals(o1.second()));
}
/**
* If tofind is a part of tokens, it finds the ****starting index***** of tofind in tokens
* If tofind is not a sub-array of tokens, then it returns null
* note that tokens sublist should have the exact elements and order as in tofind
* @param tofind array you want to find in tokens
* @param tokens
* @param matchingFunction function that takes (tofindtoken, token) pair and returns whether they match
* @return starting index of the sublist
*/
public static List<Integer> getSubListIndex(Object[] tofind, Object[] tokens, Function<Pair, Boolean> matchingFunction){
if(tofind.length > tokens.length)
return null;
List<Integer> allIndices = new ArrayList<>();
boolean matched = false;
int index = -1;
int lastUnmatchedIndex = 0;
for(int i = 0 ; i < tokens.length;){
for(int j = 0; j < tofind.length ;){
if(matchingFunction.apply(new Pair(tofind[j], tokens[i]))){
index = i;
i++;
j++;
if(j == tofind.length)
{
matched = true;
break;
}
}else{
j = 0;
i = lastUnmatchedIndex +1;
lastUnmatchedIndex = i;
index = -1;
if(lastUnmatchedIndex == tokens.length)
break;
}
if(i >= tokens.length){
index = -1;
break;
}
}
if(i == tokens.length || matched){
if(index >= 0)
//index = index - l1.length + 1;
allIndices.add(index - tofind.length + 1);
matched = false;
lastUnmatchedIndex = index;
//break;
}
}
//get starting point
return allIndices;
}
/** Returns a new array which has the numbers in the input array
* L1-normalized.
*
* @param ar Input array
* @return New array that has L1 normalized form of input array
*/
public static double[] normalize(double[] ar) {
double[] ar2 = new double[ar.length];
double total = 0.0;
for (double d : ar) {
total += d;
}
for (int i = 0; i < ar.length; i++) {
ar2[i] = ar[i]/total;
}
return ar2;
}
public static Object[] subArray(Object[] arr, int startindexInclusive, int endindexExclusive){
if(arr == null)
return arr;
Class type = arr.getClass().getComponentType();
if(endindexExclusive < startindexInclusive || startindexInclusive > arr.length -1 )
return (Object[]) Array.newInstance(type, 0);
if(endindexExclusive > arr.length)
endindexExclusive = arr.length;
if(startindexInclusive < 0)
startindexInclusive = 0;
Object[] b = (Object[]) Array.newInstance(type, endindexExclusive - startindexInclusive);
System.arraycopy(arr, startindexInclusive, b, 0, endindexExclusive - startindexInclusive);
return b;
}
public static int compareBooleanArrays(boolean[] a1, boolean[] a2) {
int len = Math.min(a1.length, a2.length);
for (int i = 0; i < len; i++) {
if (!a1[i] && a2[i]) return -1;
if (a1[i] && !a2[i]) return 1;
}
// one is a prefix of the other, or they're identical
if (a1.length < a2.length) return -1;
if (a1.length > a2.length) return 1;
return 0;
}
public static String toString(double[] doubles, String glue) {
String s = "";
for(int i = 0; i < doubles.length; i++){
if(i==0)
s = String.valueOf(doubles[i]);
else
s+= glue + String.valueOf(doubles[i]);
}
return s;
}
}