/// An example implementation of the `KnapsackItem` protocol.
struct Example: KnapsackItem, CustomStringConvertible {
    var name: String
    
    var weight: Int
    var value: Int
    
    var description: String { name }
}

let problemSetting = ZeroOneKnapsackProblem(with: [
        Example(name: "map",                    weight: 9,   value: 150),
        Example(name: "compass",                weight: 13,  value: 35),
        Example(name: "water",                  weight: 153, value: 200),
        Example(name: "sandwich",               weight: 50,  value: 160),
        Example(name: "glucose",                weight: 15,  value: 60),
        Example(name: "tin",                    weight: 68,  value: 45),
        Example(name: "banana",                 weight: 27,  value: 60),
        Example(name: "apple",                  weight: 39,  value: 40),
        Example(name: "cheese",                 weight: 23,  value: 30),
        Example(name: "beer",                   weight: 52,  value: 10),
        Example(name: "suntan cream",           weight: 11,  value: 70),
        Example(name: "camera",                 weight: 32,  value: 30),
        Example(name: "t-shirt",                weight: 24,  value: 15),
        Example(name: "trousers",               weight: 48,  value: 10),
        Example(name: "umbrella",               weight: 73,  value: 40),
        Example(name: "waterproof trousers",    weight: 42,  value: 70),
        Example(name: "waterproof overclothes", weight: 43,  value: 75),
        Example(name: "note-case",              weight: 22,  value: 80),
        Example(name: "sunglasses",             weight: 7,   value: 20),
        Example(name: "towel",                  weight: 18,  value: 12),
        Example(name: "socks",                  weight: 4,   value: 50),
        Example(name: "books",                  weight: 30,  value: 10),
    ],
    computeResultsUpTo: 400)
let result = problemSetting(limit: 400)
let (totalValue, totalWeight) = (result.value, result.weight)
print("Kept:")
result.contents.forEach { print("  \($0)") }
print("For a total value of \(totalValue) and a total weight of \(totalWeight)")