June 2018 Update

Task/Knapsack-problem-0-1/Julia/knapsack-problem-0-1-1.julia

@@ -1,20 +1,17 @@
-using MathProgBase
-
-immutable KPDSupply{S<:String, T<:Integer}
-    item::S
+struct KPDSupply{T<:Integer}
+    item::String
     weight::T
     value::T
     quant::T
 end
-function KPDSupply{S<:String, T<:Integer}(item::S, weight::T, value::T)
-    KPDSupply(item, weight, value, one(T))
-end
 
-function solve{S<:String, T<:Integer}(gear::Array{KPDSupply{S,T},1},
-                                      capacity::T)
-    w = map(x->x.weight, gear)
-    v = map(x->x.value, gear)
-    sol = mixintprog(-v, w', '<', capacity, :Bin, 0, 1)
-    sol.status == :Optimal || error("This Problem could not be solved")
-    gear[sol.sol .== 1.0]
+KPDSupply{T<:Integer}(itm::AbstractString, w::T, v::T, q::T=one(T)) = KPDSupply(itm, w, v, q)
+Base.show(io::IO, kdps::KPDSupply) = print(io, kdps.quant, " ", kdps.item, " ($(kdps.weight) kg, $(kdps.value) €)")
+
+using MathProgBase, Cbc
+function solve(gear::Vector{<:KPDSupply}, capacity::Integer)
+    w = getfield.(gear, :weight)
+    v = getfield.(gear, :value)
+    sol = mixintprog(-v, w', '<', capacity, :Bin, 0, 1, CbcSolver())
+    gear[sol.sol .≈ 1]
 end

Task/Knapsack-problem-0-1/Julia/knapsack-problem-0-1-2.julia

@@ -22,11 +22,6 @@ gear = [KPDSupply("map", 9, 150),
         KPDSupply("book", 30, 10)]
 
 pack = solve(gear, 400)
-
-println("The hiker should pack:")
-for s in pack
-    println("    ", s.item)
-end
-println()
-println("Packed Weight:  ", mapreduce(x->x.weight, +, pack))
-println("Packed Value:  ", mapreduce(x->x.value, +, pack))
+println("The hicker should pack: \n - ", join(pack, "\n - "))
+println("\nPacked weight: ", mapreduce(x -> x.weight, +, pack), " kg")
+println("Packed value: ", mapreduce(x -> x.value, +, pack), " €")