R组数据对中的数据结构

Question

我在组织流程数据时遇到了问题。要求是我们要有N艘拖船（用于运输大型船的船）和N艘要由这些拖船获得的船。每艘船都需要特定数量的拖船，所以我们有这样的东西：

setClass("tugboat", slots=list(name = "character"))

tugboat1 <- new("tugboat", name = "tugboat 1")
tugboat2 <- new("tugboat", name = "tugboat 2")
tugboat3 <- new("tugboat", name = "tugboat 3")

setClass("ship", slots=list(name = "character", tugboats_required = "numeric"))

ship1 <- new("ship", name = "Titanic", tugboats_required = 1)
ship2 <- new("ship", name = "Black Pearl", tugboats_required = 1)
ship3 <- new("ship", name = "Interceptor", tugboats_required = 1)

以为拖船不能同时参与两艘船的情况下，我可以用来装载所有可能场景的结构和逻辑，例如：

场景1 ：ship1 +拖船1，ship2 +拖船2，ship3 +拖船3

场景2 ：ship1 +拖船1，ship2 +拖船3，ship3 +拖船2

场景3 ：ship1 +拖船2，ship2 +拖船1，ship3 +拖船3

场景4 ：ship1 +拖船2，ship2 +拖船3，ship3 +拖船

场景5 ：ship1 +拖船3，ship2 +拖船1，ship3 +拖船2

场景6 ：ship1 +拖船3，ship2 +拖船1，ship3 +拖船1

在上面的示例中，我考虑每艘船仅使用一艘拖船（tugboats_required = 1），但是例如，如果此数字为2，则该船的方案应有2艘拖船。示例：

setClass("tugboat", slots=list(name = "character"))

tugboat1 <- new("tugboat", name = "tugboat 1")
tugboat2 <- new("tugboat", name = "tugboat 2")
tugboat3 <- new("tugboat", name = "tugboat 3")

setClass("ship", slots=list(name = "character", tugboats_required = "numeric"))

ship1 <- new("ship", name = "Titanic", tugboats_required = 1)
ship2 <- new("ship", name = "Black Pearl", tugboats_required = 2)

场景1 ：船1 +拖船1，船2 +拖船2 +拖船3

场景2 ：船1 +拖船2，船2 +拖船1 +拖船3

场景3 ：船1 +拖船3，船2 +拖船1 +拖船2

问题不在于数学，而是在对象声明后组织数据。