public static KnapsackConfig MutateHalf(KnapsackConfig sack, Random rand)
{
KnapsackConfig mutatedSack = new KnapsackConfig(sack);
int mutationPosition = rand.Next(itemsAmount);
if (rand.Next() % 2 == 0)
{
for (var i = 0; i < itemsAmount / 2; i++)
{
mutatedSack.swapValue(i);
}
}
else
{
for (var i = itemsAmount / 2; i < itemsAmount; i++)
{
mutatedSack.swapValue(i);
}
}
if (!IsValid(mutatedSack))
{
return(MakeValid(mutatedSack));
}
return(mutatedSack);
}
public static KnapsackConfig SinglePointMutation(KnapsackConfig sack, Random rand)
{
KnapsackConfig mutatedSack = new KnapsackConfig(sack);//copy constructor
int mutationPosition = rand.Next(itemsAmount);
var count = 0;
var iterationsToResque = 100000;
while (mutatedSack.Equals(sack) && count < iterationsToResque)//TODO - not mutate empty sack
{
mutatedSack.swapValue(mutationPosition);
if (!IsValid(mutatedSack))//somehow unrealistic
{
mutatedSack.swapValue(mutationPosition);
mutationPosition = rand.Next(itemsAmount);
}
count++;
}
if (count == iterationsToResque)
{
return(MakeValid(mutatedSack));
}
return(mutatedSack);
}