/// <summary>
/// Moves an randomly chosen element in the specified <paramref name="permutation"/> array
/// to another randomly generated position.
/// </summary>
/// <param name="random">The random number generator.</param>
/// <param name="permutation">The permutation to manipulate.</param>
public static void Apply(IRandom random, Permutation permutation) {
Permutation original = (Permutation)permutation.Clone();
int cutIndex, insertIndex, number;
cutIndex = random.Next(original.Length);
insertIndex = random.Next(original.Length);
number = original[cutIndex];
int i = 0; // index in new permutation
int j = 0; // index in old permutation
while (i < original.Length) {
if (j == cutIndex) {
j++;
}
if (i == insertIndex) {
permutation[i] = number;
i++;
}
if ((i < original.Length) && (j < original.Length)) {
permutation[i] = original[j];
i++;
j++;
}
}
}
/// <summary>
/// Moves an randomly chosen element in the specified <paramref name="permutation"/> array
/// to another randomly generated position.
/// </summary>
/// <param name="random">The random number generator.</param>
/// <param name="permutation">The permutation to manipulate.</param>
public static void Apply(IRandom random, Permutation permutation)
{
Permutation original = (Permutation)permutation.Clone();
int cutIndex, insertIndex, number;
cutIndex = random.Next(original.Length);
insertIndex = random.Next(original.Length);
number = original[cutIndex];
int i = 0; // index in new permutation
int j = 0; // index in old permutation
while (i < original.Length)
{
if (j == cutIndex)
{
j++;
}
if (i == insertIndex)
{
permutation[i] = number;
i++;
}
if ((i < original.Length) && (j < original.Length))
{
permutation[i] = original[j];
i++;
j++;
}
}
}
private static void ExchangeSubsequences(Permutation p1, int index1, Permutation p2, int index2, int subSequenceLength) {
var aux = (Permutation)p1.Clone();
for (int i = 0; i < subSequenceLength; i++) {
p1[i + index1] = p2[i + index2];
p2[i + index2] = aux[i + index1];
}
}
public static void Apply(Permutation permutation, int breakPoint1, int breakPoint2, int insertPoint)
{
Permutation original = (Permutation)permutation.Clone();
int i = 0; // index in new permutation
int j = 0; // index in old permutation
while (i < original.Length)
{
if (i == insertPoint) // copy translocated area
{
for (int k = breakPoint1; k <= breakPoint2; k++)
{
permutation[i] = original[k];
i++;
}
}
if (j == breakPoint1) // skip area between breakpoints
{
j = breakPoint2 + 1;
}
if ((i < original.Length) && (j < original.Length))
{
permutation[i] = original[j];
i++;
j++;
}
}
}
/// <summary>
/// Moves a randomly chosen interval of elements to another (randomly chosen) position in the given
/// <paramref name="permutation"/> array and reverses it.
/// </summary>
/// <param name="random">The random number generator.</param>
/// <param name="permutation">The permutation array to manipulate.</param>
public static void Apply(IRandom random, Permutation permutation) {
Permutation original = (Permutation)permutation.Clone();
int breakPoint1, breakPoint2, insertPoint, insertPointLimit;
breakPoint1 = random.Next(original.Length - 1);
breakPoint2 = random.Next(breakPoint1 + 1, original.Length);
insertPointLimit = original.Length - breakPoint2 + breakPoint1 - 1; // get insertion point in remaining part
if (insertPointLimit > 0)
insertPoint = random.Next(insertPointLimit);
else
insertPoint = 0;
int i = 0; // index in new permutation
int j = 0; // index in old permutation
while (i < original.Length) {
if (i == insertPoint) { // copy translocated area
for (int k = breakPoint2; k >= breakPoint1; k--) {
permutation[i] = original[k];
i++;
}
}
if (j == breakPoint1) { // skip area between breakpoints
j = breakPoint2 + 1;
}
if ((i < original.Length) && (j < original.Length)) {
permutation[i] = original[j];
i++;
j++;
}
}
}
public static void Apply(Permutation permutation, int startIndex, int[] scrambleArray)
{
Permutation original = (Permutation)permutation.Clone();
for (int i = 0; i < scrambleArray.Length; i++) // scramble permutation between breakpoints
{
permutation[startIndex + i] = original[startIndex + scrambleArray[i]];
}
}
/// <summary>
/// Moves a randomly chosen interval of elements to another (randomly chosen) position in the given
/// <paramref name="permutation"/> array and reverses it.
/// </summary>
/// <param name="random">The random number generator.</param>
/// <param name="permutation">The permutation array to manipulate.</param>
public static void Apply(IRandom random, Permutation permutation)
{
Permutation original = (Permutation)permutation.Clone();
int breakPoint1, breakPoint2, insertPoint, insertPointLimit;
breakPoint1 = random.Next(original.Length - 1);
breakPoint2 = random.Next(breakPoint1 + 1, original.Length);
insertPointLimit = original.Length - breakPoint2 + breakPoint1 - 1; // get insertion point in remaining part
if (insertPointLimit > 0)
{
insertPoint = random.Next(insertPointLimit);
}
else
{
insertPoint = 0;
}
int i = 0; // index in new permutation
int j = 0; // index in old permutation
while (i < original.Length)
{
if (i == insertPoint) // copy translocated area
{
for (int k = breakPoint2; k >= breakPoint1; k--)
{
permutation[i] = original[k];
i++;
}
}
if (j == breakPoint1) // skip area between breakpoints
{
j = breakPoint2 + 1;
}
if ((i < original.Length) && (j < original.Length))
{
permutation[i] = original[j];
i++;
j++;
}
}
}
public static void Apply(Permutation permutation, int breakPoint1, int breakPoint2, int insertPoint) {
Permutation original = (Permutation)permutation.Clone();
int i = 0; // index in new permutation
int j = 0; // index in old permutation
while (i < original.Length) {
if (i == insertPoint) { // copy translocated area
for (int k = breakPoint1; k <= breakPoint2; k++) {
permutation[i] = original[k];
i++;
}
}
if (j == breakPoint1) { // skip area between breakpoints
j = breakPoint2 + 1;
}
if ((i < original.Length) && (j < original.Length)) {
permutation[i] = original[j];
i++;
j++;
}
}
}
public static void Apply(Permutation permutation, int startIndex, int[] scrambleArray) {
Permutation original = (Permutation)permutation.Clone();
for (int i = 0; i < scrambleArray.Length; i++) { // scramble permutation between breakpoints
permutation[startIndex + i] = original[startIndex + scrambleArray[i]];
}
}
public static double EvaluateMove(Permutation tour, InversionMove move, Func<int, int, double> distance, DoubleArray probabilities) {
var afterMove = (Permutation)tour.Clone();
InversionManipulator.Apply(afterMove, move.Index1, move.Index2);
return AnalyticalProbabilisticTravelingSalesmanProblem.Evaluate(afterMove, distance, probabilities);
}
public static double EvaluateMove(Permutation tour, TranslocationMove move, Func<int, int, double> distance, ItemList<BoolArray> realizations) {
var afterMove = (Permutation)tour.Clone();
TranslocationManipulator.Apply(afterMove, move.Index1, move.Index1, move.Index3);
double moveQuality = 0;
var edges = new int[12];
var indices = new int[12];
edges[0] = tour.GetCircular(move.Index1 - 1);
indices[0] = DecreaseCircularIndex(tour.Length, move.Index1);
edges[1] = tour[move.Index1];
indices[1] = move.Index1;
edges[2] = tour[move.Index1];
indices[2] = move.Index1;
edges[3] = tour.GetCircular(move.Index1 + 1);
indices[3] = IncreaseCircularIndex(tour.Length, move.Index1);
edges[6] = afterMove.GetCircular(move.Index3 - 1);
indices[6] = DecreaseCircularIndex(afterMove.Length, move.Index3);
edges[7] = afterMove[move.Index3];
indices[7] = move.Index3;
edges[8] = afterMove[move.Index3];
indices[8] = move.Index3;
edges[9] = afterMove.GetCircular(move.Index3 + 1);
indices[9] = IncreaseCircularIndex(afterMove.Length, move.Index3);
if (move.Index3 > move.Index1) {
edges[4] = tour[move.Index3];
indices[4] = move.Index3;
edges[5] = tour.GetCircular(move.Index3 + 1);
indices[5] = indices[9];
edges[10] = afterMove.GetCircular(move.Index1 - 1);
indices[10] = indices[0];
edges[11] = afterMove[move.Index1];
indices[11] = move.Index1;
} else {
edges[4] = tour.GetCircular(move.Index3 - 1);
indices[4] = indices[6];
edges[5] = tour[move.Index3];
indices[5] = move.Index3;
edges[10] = afterMove[move.Index1];
indices[10] = move.Index1;
edges[11] = afterMove.GetCircular(move.Index1 + 1);
indices[11] = indices[3];
}
int[] aPosteriori = new int[12];
foreach (var realization in realizations) {
for (int i = 0; i < edges.Length; i++) {
Permutation tempPermutation;
if (i < 6) {
tempPermutation = tour;
} else {
tempPermutation = afterMove;
}
if (realization[edges[i]]) {
aPosteriori[i] = edges[i];
} else {
int j = 1;
if (i % 2 == 0) {
// find nearest predecessor in realization if source edge
while (!realization[tempPermutation.GetCircular(indices[i] - j)]) {
j++;
}
aPosteriori[i] = tempPermutation.GetCircular(indices[i] - j);
} else {
// find nearest successor in realization if target edge
while (!realization[tempPermutation.GetCircular(indices[i] + j)]) {
j++;
}
aPosteriori[i] = tempPermutation.GetCircular(indices[i] + j);
}
}
}
if (!(aPosteriori[0] == aPosteriori[2] && aPosteriori[1] == aPosteriori[3]) &&
!(aPosteriori[0] == aPosteriori[4] && aPosteriori[1] == aPosteriori[5]) &&
!(aPosteriori[2] == aPosteriori[4] && aPosteriori[3] == aPosteriori[5])) {
// compute cost difference between the two a posteriori solutions
moveQuality = moveQuality + distance(aPosteriori[6], aPosteriori[7]) + distance(aPosteriori[8], aPosteriori[9]) + distance(aPosteriori[10], aPosteriori[11]);
moveQuality = moveQuality - distance(aPosteriori[0], aPosteriori[1]) - distance(aPosteriori[2], aPosteriori[3]) - distance(aPosteriori[4], aPosteriori[5]);
}
Array.Clear(aPosteriori, 0, aPosteriori.Length);
}
// return average of cost differences
return moveQuality / realizations.Count;
}
