/// <summary>
/// Find the closest collection more than ValueThreshold.
/// </summary>
/// <param name="Items"></param>
/// <param name="WeightThreshold"></param>
/// <returns></returns>
public static WeightNode FindItemCollectionWithMostMatchValue(IEnumerable <Item> Items, double WeightThreshold)
{
int i;
int numOfMoreThanThreshold = 0;
const int BEST_SOLUTION_NUM = 3;
double maxWeight = 0.0;
WeightNode dummy = new WeightNode()
{
_Value = 0.0, _Weight = 0.0
};
LinkedList <WeightNode> retList = new LinkedList <WeightNode>();
LinkedListNode <WeightNode> node = null;
LinkedListNode <WeightNode> moreWeighNode = null;
retList.AddLast(dummy);
foreach (Item g in Items)
{
for (i = 0; i < g.Number; i++)
{
node = retList.Last;
moreWeighNode = retList.Last;
maxWeight = retList.Last.Value._Weight;
while (node != null)
{
double totalWeight = node.Value._Weight + g.Weight;
while (moreWeighNode != null)
{
if (Math.Abs(totalWeight - moreWeighNode.Value._Weight) < 0.001)
{
if (node.Value._Value + g.Value > moreWeighNode.Value._Value)
{
// employ the current node + the current grocery
WeightNode wn = new WeightNode(node.Value);
wn.AddItem(g);
moreWeighNode.Value = wn;
}
break;
}
else if (totalWeight < moreWeighNode.Value._Weight)
{
moreWeighNode = moreWeighNode.Previous;
}
else if (totalWeight > moreWeighNode.Value._Weight)
{
if ((totalWeight < maxWeight) || (totalWeight < WeightThreshold) ||
((totalWeight > WeightThreshold) && (numOfMoreThanThreshold < BEST_SOLUTION_NUM)))
{
WeightNode wn = new WeightNode(node.Value);
wn.AddItem(g);
retList.AddAfter(moreWeighNode, new LinkedListNode <WeightNode>(wn));
moreWeighNode = moreWeighNode.Next;
if (totalWeight > WeightThreshold)
{
if (numOfMoreThanThreshold > BEST_SOLUTION_NUM)
{
retList.RemoveLast();
}
else
{
numOfMoreThanThreshold++;
}
}
maxWeight = retList.Last.Value._Weight;
}
break;
}
}
node = node.Previous;
}
}
}
return(retList.First(o => (o._Weight >= WeightThreshold)));
}
/// <summary>
/// Select some grocery from Groceries and make sure
/// 1. the total weight is less than MaxWeight
/// 2. the total value is highest.
///
/// </summary>
/// <param name="Groceries"></param>
/// <param name="MaxWeight"></param>
/// <returns></returns>
public static WeightNode Process(IEnumerable <Item> Groceries, double MaxWeight)
{
/*
* (Value/Weight)
*
* retList
* |
* +- dummy (0.0/0.0)
* |
* +- WeightNode (V/W) --> Item0 -> Item1 -> ... -> ItemN
* |
* + ...
* |
* +- WeightNode (V/Capacity) -> Item0 -> Item1 -> ... ItemN
*
*/
int i;
WeightNode dummy = new WeightNode()
{
_Value = 0.0, _Weight = 0.0
};
LinkedList <WeightNode> retList = new LinkedList <WeightNode>();
LinkedListNode <WeightNode> node = null;
LinkedListNode <WeightNode> moreWeighNode = null;
retList.AddLast(dummy);
foreach (Item g in Groceries)
{
for (i = 0; i < g.Number; i++)
{
node = retList.Last;
moreWeighNode = retList.Last;
while (node != null)
{
double totalWeight = node.Value._Weight + g.Weight;
if (totalWeight <= MaxWeight)
{
while (moreWeighNode != null)
{
if (Math.Abs(totalWeight - moreWeighNode.Value._Weight) < 0.001)
{
if (node.Value._Value + g.Value > moreWeighNode.Value._Value)
{
// employ the current node + the current grocery
WeightNode wn = new WeightNode(node.Value);
wn.AddItem(g);
moreWeighNode.Value = wn;
}
break;
}
else if (totalWeight < moreWeighNode.Value._Weight)
{
moreWeighNode = moreWeighNode.Previous;
}
else if (totalWeight > moreWeighNode.Value._Weight)
{
WeightNode wn = new WeightNode(node.Value);
wn.AddItem(g);
//moreWeighNode.AddGrocery(g);
retList.AddAfter(moreWeighNode, new LinkedListNode <WeightNode>(wn));
moreWeighNode = moreWeighNode.Next;
break;
}
}
}
node = node.Previous;
}
}
}
double maxValue = retList.Max(o => o._Value);
return(retList.Last(o => (o._Value == maxValue)));
}