public IList <ItemInfo> Calculate(int sourceItemLength, IDictionary <int, int> targetItemCountsByLengths)
{
foreach (var pair in targetItemCountsByLengths)
{
var targetItemLength = pair.Key;
if (targetItemLength > sourceItemLength)
{
throw new ArgumentException();
}
}
CalculationState calculationState = new CalculationState();
FindMinimum(sourceItemLength, targetItemCountsByLengths, new List <ItemInfo>(), calculationState);
return(calculationState.MinimumItemInfos);
}
private static void FindMinimum(int sourceItemLength,
IDictionary <int, int> targetItemCountsByLengths,
IList <ItemInfo> actualItemInfos,
CalculationState calculationState)
{
if (targetItemCountsByLengths.Count == 0)
{
var isActualItemInfosMinimum = actualItemInfos.Count < calculationState.ItemCount;
if (isActualItemInfosMinimum)
{
calculationState.MinimumItemInfos = actualItemInfos;
}
return;
}
var stateHash = ItemInfoHelper.GetHash(actualItemInfos);
var isStateVisited = calculationState.VisitedStateHashes.Contains(stateHash);
if (isStateVisited)
{
return;
}
calculationState.VisitedStateHashes.Add(stateHash);
foreach (var pair in targetItemCountsByLengths)
{
var currentItemLength = pair.Key;
var copiedItemCountsByLengths = new Dictionary <int, int>(targetItemCountsByLengths);
copiedItemCountsByLengths[currentItemLength]--;
if (copiedItemCountsByLengths[currentItemLength] == 0)
{
copiedItemCountsByLengths.Remove(currentItemLength);
}
foreach (var currentItemInfo in actualItemInfos)
{
var hasFreeLength = ItemInfoHelper.GetFreeLength(currentItemInfo) >= currentItemLength;
if (!hasFreeLength)
{
continue;
}
var dictionary = actualItemInfos.ToDictionary(x => x, x => new ItemInfo(x));
var copiedItemInfos = new List <ItemInfo>(dictionary.Values);
dictionary[currentItemInfo].TargetItemLengths.Add(currentItemLength);
FindMinimum(sourceItemLength, copiedItemCountsByLengths, copiedItemInfos, calculationState);
}
{
var dictionary = actualItemInfos.ToDictionary(x => x, x => new ItemInfo(x));
var copiedItemInfos = new List <ItemInfo>(dictionary.Values)
{
new ItemInfo(sourceItemLength, currentItemLength)
};
FindMinimum(sourceItemLength, copiedItemCountsByLengths, copiedItemInfos, calculationState);
}
}
}