public override DecisionSolution Solve(DecisionKnapsackInstance instance)
{
var priceSum = instance.GetPriceOfAllItems();
if (instance.MinimalPrice > priceSum)
{
return new DecisionSolution {
KnapsackInstance = instance, NumberOfSteps = 1, PermutationExists = false
}
}
;
if (instance.MinimalPrice == 0)
{
return new DecisionSolution {
KnapsackInstance = instance, NumberOfSteps = 1, PermutationExists = true
}
}
;
var priceRange = Math.Max(0.01, priceSum - instance.MinimalPrice);
//the list is being processed backwards in the algorithm, so it must be sorted in ascending order
instance.Items = instance.Items.OrderBy(a => Math.Max(a.Weight / instance.KnapsackSize, a.Price / priceRange)).
ToList();
return(new DecisionBranchBound().Solve(instance));
}
}
}
public override DecisionResult Solve(DecisionKnapsackInstance knapsackInstance)
{
numberOfSteps = 0;
bool permutationExists = DoesSolutionExist(knapsackInstance.Items.Count, 0, 0, knapsackInstance.GetPriceOfAllItems(), knapsackInstance);
return(new DecisionResult {
KnapsackInstance = knapsackInstance, NumberOfSteps = numberOfSteps, PermutationExists = permutationExists
});
}