// "Smart mutation" - try to swap and improve the distance
private void mutateSmart(TSPSolution initial)
{
PermutationStandard current = new PermutationStandard(initial);
var start = current.eval();
var best = start;
var bestX = 0;
var bestY = 0;
for (int i = 0; i < current.perm.Length; ++i)
{
for (int j = 0; j < current.perm.Length; ++j)
{
current.swap(i, j);
var temp = current.eval();
current.swap(j, i);
if (temp < best)
{
best = temp;
bestX = i;
bestY = j;
}
}
}
if (best < start)
{
current.swap(bestX, bestY);
current.applyToTSPSolution(initial);
}
}
/// <summary>
/// Tato metoda by mela vylepsit reseni ulozene v promenne "current". Kvalitu reseni je mozne ziskat volanim "current.eval()". Je mozne napr. prohodit nektere prvky v permutaci pomoci metody "current.swap(int i, int j)".
/// Pokud uz soucasne reseni nelze vylepsit, metoda by mela nastavit promenou "stop" na "true", coz zpusobi, ze prohledavani skonci.
/// Pro vylepseni (nebo obecne zmenu) reseni pouzijte nekterou variantu Hill-Climbingu.
/// </summary>
private void goOneStepII()
{
var start = current.eval();
var best = start;
var bestX = 0;
var bestY = 0;
for (int i = 0; i < current.perm.Length; ++i)
{
for (int j = 0; j < current.perm.Length; ++j)
{
current.swap(i, j);
var temp = current.eval();
current.swap(j, i);
if (temp < best)
{
best = temp;
bestX = i;
bestY = j;
}
}
}
if (best >= start)
{
stop = true;
}
else
{
current.swap(bestX, bestY);
}
}
// "Dumb mutation" - just swap some elements
private void mutateDumb(TSPSolution initial)
{
PermutationStandard current = new PermutationStandard(initial);
current.swap(rnd.Next(current.size), rnd.Next(current.size));
current.applyToTSPSolution(initial);
}
