RosettaCodeData/Task/Knapsack-problem-Continuous/Wren/knapsack-problem-continuous...

55 lines
1.5 KiB
Plaintext

import "./fmt" for Fmt
import "./math" for Math
import "./sort" for Sort
class Item {
construct new(name, weight, value) {
_name = name
_weight = weight
_value = value
}
name { _name }
weight { _weight }
value { _value }
}
var items = [
Item.new("beef", 3.8, 36),
Item.new("pork", 5.4, 43),
Item.new("ham", 3.6, 90),
Item.new("greaves", 2.4, 45),
Item.new("flitch", 4, 30),
Item.new("brawn", 2.5, 56),
Item.new("welt", 3.7, 67),
Item.new("salami", 3.0, 95),
Item.new("sausage", 5.9, 98)
]
var maxWeight = 15
// sort items by value per unit weight in descending order
var cmp = Fn.new { |i, j| (j.value/j.weight - i.value/i.weight).sign }
Sort.insertion(items, cmp)
System.print("Item Chosen Weight Value Percentage")
System.print("----------- ------ ------ ----------")
var w = maxWeight
var itemCount = 0
var sumValue = 0
for (item in items) {
itemCount = itemCount + 1
if (item.weight <= w) {
sumValue = sumValue + item.value
Fmt.print("$-11s $3.1f $5.2f 100.00", item.name, item.weight, item.value)
} else {
var value = Math.toPlaces(w / item.weight * item.value, 2)
var percentage = Math.toPlaces(w / item.weight * 100, 2)
sumValue = sumValue + value
Fmt.print("$-11s $3.1f $5.2f $6.2f", item.name, w, value, percentage)
break
}
w = w - item.weight
if (w == 0) break
}
System.print("----------- ------ ------")
Fmt.print("$d items 15.0 $6.2f", itemCount, sumValue)