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

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using Printf
struct KPCSupply{T<:Real}
item::String
weight::T
value::T
uvalue::T
end
function KPCSupply(item::AbstractString, weight::Real, value::Real)
w, v = promote(weight, value)
KPCSupply(item, w, v, v / w)
end
Base.show(io::IO, s::KPCSupply) = print(io, s.item, @sprintf " (%.2f kg, %.2f €, %.2f €/kg)" s.weight s.value s.uvalue)
Base.isless(a::KPCSupply, b::KPCSupply) = a.uvalue < b.uvalue
function solve(store::Vector{KPCSupply{T}}, capacity::Real) where T<:Real
sack = similar(store, 0) # vector like store, but of length 0
kweight = zero(T)
for s in sort(store, rev = true)
if kweight + s.weight ≤ capacity
kweight += s.weight
push!(sack, s)
else
w = capacity - kweight
v = w * s.uvalue
push!(sack, KPCSupply(s.item, w, v, s.value))
break
end
end
return sack
end