RosettaCodeData/Task/Knapsack-problem-Unbounded/Groovy/knapsack-problem-unbounded-...

25 lines
1.0 KiB
Groovy

def totalWeight = { list -> list.collect{ it.item.weight * it.count }.sum() }
def totalVolume = { list -> list.collect{ it.item.volume * it.count }.sum() }
def totalValue = { list -> list.collect{ it.item.value * it.count }.sum() }
def knapsackUnbounded = { possibleItems, BigDecimal weightMax, BigDecimal volumeMax ->
def n = possibleItems.size()
def wm = weightMax.unscaledValue()
def vm = volumeMax.unscaledValue()
def m = (0..n).collect{ i -> (0..wm).collect{ w -> (0..vm).collect{ v -> [] } } }
(1..wm).each { w ->
(1..vm).each { v ->
(1..n).each { i ->
def item = possibleItems[i-1]
def wi = item.weight.unscaledValue()
def vi = item.volume.unscaledValue()
def bi = [w.intdiv(wi),v.intdiv(vi)].min()
m[i][w][v] = (0..bi).collect{ count ->
m[i-1][w - wi * count][v - vi * count] + [[item:item, count:count]]
}.max(totalValue).findAll{ it.count }
}
}
}
m[n][wm][vm]
}