org.chocosolver.util.objects.setDataStructures.iterable.IntIterableRangeSet Maven / Gradle / Ivy
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/*
* This file is part of choco-solver, http://choco-solver.org/
*
* Copyright (c) 2019, 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.objects.setDataStructures.iterable;
import org.chocosolver.solver.exception.SolverException;
import org.chocosolver.util.objects.setDataStructures.ISetIterator;
import org.chocosolver.util.objects.setDataStructures.SetType;
import java.util.Arrays;
import java.util.function.IntConsumer;
/**
* Concrete implementation of {@link IntIterableSet} wherein values are stored in range set.
* A range is made of two ints, the lower bound and the upper bound of the range.
* A range can be a singleton, in that case, the lb and the ub are equal.
* If the upper bound of range A is equal to lower bound of range B, then the two ranges can be merged into a single one.
*
* Project: choco.
*
* @author Charles Prud'homme
* @since 14/01/2016.
*/
public class IntIterableRangeSet implements IntIterableSet {
//***********************************************************************************
// VARIABLES
//***********************************************************************************
public static final int MIN = Integer.MAX_VALUE / -2;
public static final int MAX = Integer.MAX_VALUE / 2;
/**
* Store elements
*/
protected int[] ELEMENTS;
/**
* Used size in {@link #ELEMENTS}.
* To get the number of range simply divide by 2.
*/
protected int SIZE;
/**
* Total number of elements in the set
*/
protected int CARDINALITY;
/** Create an ISet iterator */
private ISetIterator iter;
/**
* Every public method must preserve these invariants.
*/
private void checkInvariants() {
assert SIZE <= ELEMENTS.length;
assert (SIZE & 1) == 0; // is even
assert CARDINALITY >= 0;
}
//***********************************************************************************
// CONSTRUCTOR
//***********************************************************************************
/**
* Create an interval-based ordered set
*/
public IntIterableRangeSet() {
ELEMENTS = new int[10];
SIZE = 0;
CARDINALITY = 0;
}
/**
* Create an interval-based ordered set initialized to [a,b]
*
* @param a lower bound of the interval
* @param b upper bound of the interval
*/
public IntIterableRangeSet(int a, int b) {
if (a > b) {
throw new IndexOutOfBoundsException("Incorrect bounds [" + a + "," + b + "]");
}
ELEMENTS = new int[10];
SIZE = 2;
CARDINALITY = Math.addExact(b + 1, -a);
ELEMENTS[0] = a;
ELEMENTS[1] = b;
}
/**
* Create an interval-based ordered set initialized to singleton {e}
* @param e singleton value
*/
public IntIterableRangeSet(int e) {
ELEMENTS = new int[10];
SIZE = 2;
CARDINALITY = 1;
ELEMENTS[0] = ELEMENTS[1] = e;
}
/**
* Create an interval-based ordered set initialized to an array of values
* @param values some values
*/
public IntIterableRangeSet(int[] values) {
this();
addAll(values);
}
//***********************************************************************************
// METHODS
//***********************************************************************************
@Override
public String toString() {
StringBuilder st = new StringBuilder();
if (SIZE == 0) {
st.append('\u2205');
} else {
for (int i = 0; i < SIZE - 1; i += 2) {
if (i == 0 && ELEMENTS[i] == MIN) {
st.append('(').append("-∞");
} else {
st.append('[').append(ELEMENTS[i]);
}
st.append(',');
if (ELEMENTS[i + 1] == MAX) {
st.append("+∞").append(")∪");
} else {
st.append(ELEMENTS[i + 1]).append("]∪");
}
}
st.deleteCharAt(st.length() - 1);
}
return st.toString();
}
public String toSmartString() {
StringBuilder st = new StringBuilder();
st.append("{");
for (int i = 0; i < SIZE - 1; i += 2) {
if (ELEMENTS[i] == ELEMENTS[i + 1]) {
st.append(ELEMENTS[i]).append(',');
} else {
st.append(ELEMENTS[i]).append("..").append(ELEMENTS[i + 1]).append(',');
}
}
if (SIZE > 0) st.deleteCharAt(st.length() - 1);
st.append("}");
return st.toString();
}
/**
* @return number of ranges in this
*/
public int getNbRanges() {
return SIZE >> 1;
}
public int cardinality() {
return CARDINALITY;
}
public int minOfRange(int r) {
return ELEMENTS[r << 1];
}
public int maxOfRange(int r) {
return ELEMENTS[(r << 1) + 1];
}
@Override
public int min() {
if (isEmpty()) throw new IllegalStateException("cannot find minimum of an empty set");
return ELEMENTS[0];
}
@Override
public int max() {
if (isEmpty()) throw new IllegalStateException("cannot find maximum of an empty set");
return ELEMENTS[SIZE - 1];
}
@Override
public boolean add(int e) {
boolean modified = false;
int p = rangeOf(e);
// if e is not in a range
if (p < 0) {
grow(SIZE + 2);
int i = (-p - 1) << 1;
//if (i > 0) {
int c = i > 0 && ELEMENTS[i - 1] + 1 == e ? 1 : 0;
c += i < SIZE && e == ELEMENTS[i] - 1 ? 2 : 0;
switch (c) {
case 0:
// insert a new range
System.arraycopy(ELEMENTS, i, ELEMENTS, i + 2, SIZE - i);
ELEMENTS[i] = ELEMENTS[i + 1] = e;
SIZE += 2;
break;
case 1:
// e is the new lower bound
assert ELEMENTS[i - 1] + 1 == e;
ELEMENTS[i - 1] = e;
break;
case 2:
// e is the new upper bound
assert ELEMENTS[i] - 1 == e;
ELEMENTS[i] = e;
break;
case 3:
// merge two ranges
System.arraycopy(ELEMENTS, i + 1, ELEMENTS, i - 1, SIZE - i);
SIZE -= 2;
break;
default:
throw new SolverException("Unexpected mask " + c);
}
modified = true;
CARDINALITY++;
}
return modified;
}
@Override
public boolean addAll(int... values) {
int c = CARDINALITY;
for (int i = 0; i < values.length; i++) {
add(values[i]);
}
return CARDINALITY - c > 0;
}
@Override
public boolean addAll(IntIterableSet set) {
if (set.isEmpty()) return false;
int c = CARDINALITY;
if (!set.isEmpty()) {
int v = set.min();
while (v < Integer.MAX_VALUE) {
add(v);
v = set.nextValue(v);
}
}
return CARDINALITY > c;
}
public boolean addAll(IntIterableRangeSet set) {
int c = CARDINALITY;
if (!set.isEmpty()) {
int s2 = set.SIZE >> 1;
if (s2 > 0) {
int j = 0;
do {
addBetween(set.ELEMENTS[j << 1], set.ELEMENTS[(j << 1) + 1]);
j++;
} while (j < s2);
}
}
return CARDINALITY < c;
}
@Override
public boolean retainAll(IntIterableSet set) {
int c = CARDINALITY;
if (set.isEmpty()) {
this.clear();
} else {
int last = max();
for (int i = min(); i <= last; i = nextValue(i)) {
if (!set.contains(i)) {
remove(i);
}
}
}
return c - CARDINALITY > 0;
}
public boolean retainAll(IntIterableRangeSet set) {
int c = CARDINALITY;
if (set.isEmpty()) {
this.clear();
return c - CARDINALITY > 0;
} else {
return IntIterableSetUtils.intersectionOf(this, set);
}
}
@Override
public boolean remove(int e) {
boolean modified = false;
int p = rangeOf(e);
// if e is not in a range
if (p >= 0) {
int i = (p - 1) << 1;
int c = ELEMENTS[i] == e ? 1 : 0;
c += ELEMENTS[i + 1] == e ? 2 : 0;
switch (c) {
case 0:
// split range in two ranges
grow(SIZE + 2);
System.arraycopy(ELEMENTS, i + 1, ELEMENTS, i + 3, SIZE - i - 1);
ELEMENTS[i + 1] = e - 1;
ELEMENTS[i + 2] = e + 1;
SIZE += 2;
break;
case 1:
// increase lower of the range
ELEMENTS[i]++;
break;
case 2:
// decrease upper of the range
ELEMENTS[i + 1]--;
break;
case 3:
// delete a range
System.arraycopy(ELEMENTS, i + 2, ELEMENTS, i, SIZE - i - 2);
SIZE -= 2;
break;
default:
throw new SolverException("Unexpected mask " + c);
}
modified = true;
CARDINALITY--;
}
return modified;
}
@Override
public boolean removeAll(IntIterableSet set) {
int c = CARDINALITY;
if (!set.isEmpty()) {
int v = set.min();
while (v < Integer.MAX_VALUE) {
remove(v);
v = set.nextValue(v);
}
}
return CARDINALITY < c;
}
public boolean removeAll(IntIterableRangeSet set) {
int c = CARDINALITY;
if (!set.isEmpty()) {
int s2 = set.SIZE >> 1;
if (s2 > 0) {
int j = 0;
do {
removeBetween(set.ELEMENTS[j << 1], set.ELEMENTS[(j << 1) + 1]);
j++;
} while (j < s2);
}
}
return CARDINALITY < c;
}
@Override
public void clear() {
CARDINALITY = 0;
SIZE = 0;
}
@Override
public SetType getSetType() {
return SetType.RANGESET;
}
public boolean addBetween(int a, int b) {
if (a > b) {
throw new IndexOutOfBoundsException("Incorrect bounds [" + a + "," + b + "]");
}
boolean change;
int s1 = SIZE >> 1;
int s2 = 1; // since a <= b
if (s1 > 0) {
int i = 0, j = 0;
int s = 0, c = 0;
int[] e = new int[SIZE];
int lbi, ubi, lbj, ubj, lb, ub;
lb = lbi = ELEMENTS[0];
ub = ubi = ELEMENTS[1];
lbj = a;
ubj = b;
if (lb > lbj) {
lb = lbj;
ub = ubj;
}
boolean extend;
// TODO: replace while loop with rangeOf
while (i < s1 || j < s2) {
extend = false;
if (lb - 1 <= lbi && lbi <= ub + 1) {
ub = Math.max(ub, ubi);
extend = i < s1;
if (++i < s1) {
lbi = ELEMENTS[i << 1];
ubi = ELEMENTS[(i << 1) + 1];
}
}
if (lb - 1 <= lbj && lbj <= ub + 1) {
ub = Math.max(ub, ubj);
extend |= j < s2;
j++;
}
if (!extend) {
if (s + 2 > e.length) {
// overflow-conscious code
int oldCapacity = e.length;
int newCapacity = oldCapacity + (oldCapacity >> 1);
if (newCapacity < s + 2)
newCapacity = s + 2;
// minCapacity is usually close to size, so this is a win:
e = Arrays.copyOf(e, newCapacity);
}
e[s++] = lb;
e[s++] = ub;
c += ub - lb + 1;
if (i < s1) {
lb = lbi;
ub = ubi;
if (j < s2 && lbi > lbj) {
lb = lbj;
ub = ubj;
}
} else if (j < s2) {
lb = lbj;
ub = ubj;
}
}
}
if (s + 2 > e.length) {
// overflow-conscious code
int oldCapacity = e.length;
int newCapacity = oldCapacity + (oldCapacity >> 1);
if (newCapacity < s + 2)
newCapacity = s + 2;
// minCapacity is usually close to size, so this is a win:
e = Arrays.copyOf(e, newCapacity);
}
e[s++] = lb;
e[s++] = ub;
c += ub - lb + 1;
ELEMENTS = e;
SIZE = s;
change = (CARDINALITY != c);
CARDINALITY = c;
} else {
grow(1);
ELEMENTS[0] = a;
ELEMENTS[1] = b;
SIZE = 2;
CARDINALITY = Math.addExact(b + 1, -a);
change = true;
}
return change;
}
@Override
public boolean removeBetween(int f, int t) {
boolean rem = false;
if (f > t) {
throw new IllegalArgumentException("Cannot remove from empty range [" + f + "," + t + "]");
}
int rf = rangeOf(f);
if (rf < 0) {
// find closest after
rf *= -1;
if (rf > SIZE >> 1) {
return false;
}
f = ELEMENTS[(rf - 1) << 1];
}
assert rf > 0;
int rt = rangeOf(t, (rf - 1) << 1, SIZE);
if (rt < 0) {
// find closest range before
rt = -rt - 1;
if (rt < 1) {
return false;
}
t = ELEMENTS[((rt - 1) << 1) + 1];
}
assert rt > 0;
int i = (rf - 1) << 1;
int j = (rt - 1) << 1;
if (rf <= rt) {
int dcard = -(f - ELEMENTS[i] + ELEMENTS[j + 1] - t);
dcard += ELEMENTS[i + 1] - ELEMENTS[i] + 1;
if (rf < rt) {
for (int k = i + 2; k <= j + 1; k += 2) {
dcard += ELEMENTS[k + 1] - ELEMENTS[k] + 1;
}
// remove useless range
System.arraycopy(ELEMENTS, j + 1, ELEMENTS, i + 1, SIZE - (j + 1));
SIZE -= (rt - rf) << 1;
}
CARDINALITY -= dcard;
int c = ELEMENTS[i] == f ? 1 : 0;
c += ELEMENTS[i + 1] == t ? 2 : 0;
switch (c) {
case 0: // split the range into two ranges
grow(SIZE + 2);
System.arraycopy(ELEMENTS, i, ELEMENTS, i + 2, SIZE - i);
ELEMENTS[i + 1] = f - 1;
ELEMENTS[i + 2] = t + 1;
SIZE += 2;
break;
case 1: // update the lower bound of the range
ELEMENTS[i] = t + 1;
break;
case 2: // update the upper bound of the range
ELEMENTS[i + 1] = f - 1;
break;
case 3: // remove the range
if (i < SIZE - 2) {
System.arraycopy(ELEMENTS, i + 2, ELEMENTS, i, SIZE - (i + 2));
}
SIZE -= 2;
break;
}
rem = true;
}
return rem;
}
public boolean retainBetween(int f, int t) {
if (f > t) {
throw new IllegalArgumentException("Cannot retain from empty range [" + f + "," + t + "]");
}
int rf = rangeOf(f);
if (rf < 0) {
// find closest after
rf *= -1;
if (rf << 1 > SIZE) {
this.clear();
return true;
}
f = ELEMENTS[(rf - 1) << 1];
}
assert rf > 0;
int rt = rangeOf(t, (rf - 1) << 1, SIZE);
if (rt < 0) {
// find closest range before
rt = -rt - 1;
if (rt < 1) {
this.clear();
return true;
}
t = ELEMENTS[((rt - 1) << 1) + 1];
}
assert rt > 0;
int i = (rf - 1) << 1;
int j = (rt - 1) << 1;
if (rf <= rt) {
ELEMENTS[i] = f;
ELEMENTS[j + 1] = t;
System.arraycopy(ELEMENTS, i, ELEMENTS, 0, j - i + 2);
SIZE = (rt - rf + 1) << 1;
CARDINALITY = 0;
for (int k = 0; k < SIZE; k += 2) {
CARDINALITY += ELEMENTS[k + 1] - ELEMENTS[k] + 1;
}
} else {
this.clear();
}
return true;
}
@Override
public int nextValue(int e) {
e++;
int p = rangeOf(e);
int next = Integer.MAX_VALUE;
if (p == -1 && SIZE > 0) {
next = ELEMENTS[0];
} else if (p >= 0) {
next = e;
} else if (p > -((SIZE >> 1) + 1)) {
return ELEMENTS[(-p - 1) << 1];
}
return next;
}
@Override
public int nextValueOut(int e) {
e++;
int p = rangeOf(e);
int next;
if (p >= 0) {
next = ELEMENTS[((p - 1) << 1) + 1] + 1;
} else {
next = e;
}
return next;
}
@Override
public int previousValue(int e) {
e--;
int p = rangeOf(e);
int prev = Integer.MIN_VALUE;
if (p == -((SIZE >> 1) + 1) && SIZE > 0) {
prev = ELEMENTS[SIZE - 1];
} else if (p >= 0) {
prev = e;
} else if (p < -1) {
prev = ELEMENTS[((-p - 1) << 1) - 1];
}
return prev;
}
@Override
public int previousValueOut(int e) {
e--;
int p = rangeOf(e);
int prev;
if (p >= 0) {
prev = ELEMENTS[((p - 1) << 1)] - 1;
} else {
prev = e;
}
return prev;
}
@Override
public boolean contains(int o) {
if (CARDINALITY == 1) {
return ELEMENTS[0] == o;
}
return rangeOf(o) >= 0;
}
@Override
public IntIterableRangeSet duplicate() {
IntIterableRangeSet ir = new IntIterableRangeSet();
ir.ELEMENTS = this.ELEMENTS.clone();
ir.CARDINALITY = this.CARDINALITY;
ir.SIZE = this.SIZE;
checkInvariants();
return ir;
}
public IntIterableRangeSet copyFrom(IntIterableRangeSet me) {
this.clear();
for (int s = 0; s < me.SIZE; s += 2) {
pushRange(me.ELEMENTS[s], me.ELEMENTS[s + 1]);
}
checkInvariants();
return this;
}
@Override
public int size() {
return CARDINALITY;
}
@Override
public ISetIterator newIterator() {
return new ISetIterator() {
private boolean started = false;
private int current;
@Override
public void reset() {
started = false;
}
@Override
public boolean hasNext() {
if (started) {
return nextValue(current) < Integer.MAX_VALUE;
} else {
return !isEmpty();
}
}
@Override
public int nextInt() {
if (started) {
current = nextValue(current);
} else {
started = true;
current = min();
}
return current;
}
};
}
/**
* add the value x to all integers stored in this set
*
* @param x value to add
*/
public void plus(int x) {
for (int i = 0; i < SIZE; i++) {
ELEMENTS[i] += x;
}
}
@Override
public ISetIterator iterator() {
if (iter == null) {
iter = newIterator();
}
iter.reset();
return iter;
}
/**
* subtract the value x to all integers stored in this set
*
* @param x value to add
*/
public void minus(int x) {
for (int i = 0; i < SIZE; i++) {
ELEMENTS[i] -= x;
}
}
/**
* multiply by x to all integers stored in this set
*
* @param x value to add
*/
public void times(int x) {
if (x > 0) {
for (int i = 0; i < SIZE; i++) {
ELEMENTS[i] *= x;
}
CARDINALITY *= x;
} else if (x < 0) {
for (int i = 0; i < (SIZE >> 1); i++) {
int t = ELEMENTS[i];
ELEMENTS[i] = ELEMENTS[SIZE - i - 1] * x;
ELEMENTS[SIZE - i - 1] = t * x;
}
CARDINALITY *= -x;
} else {
this.clear();
this.add(0);
}
}
/**
* By convention, range are numbered starting from 1 (not 0).
*
* @param x a value
* @return the range index if the value is in the set or -range point - 1 otherwise
* where range point corresponds to the range directly greater than the key
*/
public int rangeOf(int x) {
return rangeOf(x, 0, SIZE);
}
/**
* By convention, range are numbered starting from 1 (not 0).
*
* @param x a value
* @return the range index if the value is in the set or -range point - 1 otherwise
* where range point corresponds to the range directly greater than the key
*/
protected int rangeOf(int x, int fromIndex, int toIndex) {
if (toIndex - fromIndex < 15) {
int q = -((toIndex >> 1) + 1);
for (int r = fromIndex; r < toIndex - 1; r += 2) {
if (x < ELEMENTS[r]) {
q = -((r >> 1) + 1);
break;
} else if (x <= ELEMENTS[r + 1]) {
q = (r >> 1) + 1;
break;
}
}
return q;
}
int p = Arrays.binarySearch(ELEMENTS, fromIndex, toIndex, x);
// if pos is positive, the value is a bound of a range
if (p >= 0) {
p >>= 1;
} else if (p == -1) {
p--;
} else if (p == -(toIndex + 1)) {
p = -((toIndex >> 1) + 2);// -2 because add 1 as last instruction
} else {
// is x in a range or not
p = -(p + 1);
p >>= 1;
if (!(ELEMENTS[p << 1] < x && x < ELEMENTS[(p << 1) + 1])) {
p = -(p + 2); // -2 because add 1 as last instruction
}
}
return p + 1;
}
/**
* Increases the capacity to ensure that it can hold at least the
* number of elements specified by the minimum capacity argument.
*
* @param minCapacity the desired minimum capacity
*/
void grow(int minCapacity) {
if (minCapacity - ELEMENTS.length > 0) {
// overflow-conscious code
int oldCapacity = ELEMENTS.length;
int newCapacity = oldCapacity + (oldCapacity >> 1);
if (newCapacity - minCapacity < 0)
newCapacity = minCapacity;
// minCapacity is usually close to size, so this is a win:
ELEMENTS = Arrays.copyOf(ELEMENTS, newCapacity);
}
}
/**
* Push a range at the end of this set
* @param lb lower bound of the range
* @param ub upper bound of the range
*/
void pushRange(int lb, int ub) {
assert SIZE == 0 || ELEMENTS[SIZE - 1] < lb - 1;
assert lb <= ub;
grow(SIZE + 2);
ELEMENTS[SIZE++] = lb;
ELEMENTS[SIZE++] = ub;
CARDINALITY += Math.addExact(ub + 1, -lb);
}
/**
* Compact the array in memory
*/
public void compact() {
ELEMENTS = Arrays.copyOf(ELEMENTS, SIZE);
}
/**
* Turn this into the complement of this.
* calling :
*
set.flip().flip()
* goes back to the original set.
* @return this turned into its complement, based on {@link #MIN} and {@link #MAX}
*/
public IntIterableRangeSet flip() {
return flip(MIN, MAX);
}
/**
* Turn this into the complement of this.
* calling :
* set.flip().flip()
* goes back to the original set.
* @return this turned into its complement, based on lb, ub
*/
public IntIterableRangeSet flip(int lb, int ub) {
if (SIZE == 0) { // empty set
pushRange(lb, ub);
} else if (ELEMENTS[0] <= lb && ELEMENTS[1] >= ub) { // all
clear();
} else {
boolean smin = ELEMENTS[0] <= lb;
boolean emax = ELEMENTS[SIZE - 1] >= ub;
if (!smin && !emax) {
grow(SIZE + 2);
SIZE += 2;
}
if (smin && emax) {
SIZE -= 2;
}// else no need to change the length of ELEMENTS
// two cases:
CARDINALITY = 0;
if (smin) {
int i = 1;
int max = emax ? SIZE : SIZE - 2;
while (i < max) {
ELEMENTS[i - 1] = ELEMENTS[i++] + 1;
ELEMENTS[i - 1] = ELEMENTS[i++] - 1;
CARDINALITY += ELEMENTS[i - 2] - ELEMENTS[i - 3] + 1;
}
if (!emax) {
ELEMENTS[i - 1] = ELEMENTS[i++] + 1;
ELEMENTS[i - 1] = ub;
CARDINALITY += ELEMENTS[i - 1] - ELEMENTS[i - 2] + 1;
}
} else {
int i = SIZE - 1;
if (!emax) {
ELEMENTS[i--] = ub;
} else {
ELEMENTS[i--] = ELEMENTS[i] - 1;
}
while (i > 0) {
ELEMENTS[i] = ELEMENTS[--i] + 1;
try {
CARDINALITY += ELEMENTS[i + 2] - ELEMENTS[i + 1] + 1;
} catch (ArrayIndexOutOfBoundsException e) {
System.out.print("tt");
}
ELEMENTS[i] = ELEMENTS[--i] - 1;
}
ELEMENTS[i] = lb;
CARDINALITY += ELEMENTS[i + 1] - ELEMENTS[i] + 1;
}
}
return this;
}
/**
* Apply the operation c on each value in this set
* @param c an operation
*/
public void forEachValueIn(IntConsumer c) {
for (int s = 0; s < SIZE; s += 2) {
for (int i = ELEMENTS[s]; i <= ELEMENTS[s + 1]; i++) {
c.accept(i);
}
}
}
/**
* Apply the operation c on each value in : ]{@link #min()}, {@link #max()}[ \ this set.
* @param c an operation
*/
public void forEachValueOut(IntConsumer c) {
for (int s = 1; s < SIZE - 1; s += 2) {
for (int i = ELEMENTS[s] + 1; i < ELEMENTS[s + 1]; i++) {
c.accept(i);
}
}
}
/**
* @return an array containing all of the elements in this set in
* sorted sequence
*/
public int[] toArray() {
int[] a = new int[CARDINALITY];
int k = 0;
for (int i = 0; i < SIZE - 1; i += 2) {
if (ELEMENTS[i] == ELEMENTS[i + 1]) {
a[k++] = ELEMENTS[i];
} else {
for (int j = ELEMENTS[i]; j <= ELEMENTS[i + 1]; j++) {
a[k++] = j;
}
}
}
return a;
}
}