去元组替代

Question

我正在学习麻省理工学院计算思维和数据科学导论课程第 2课讲座 PDF，我正在尝试将以下树搜索算法 python 代码翻译成 Golang。主要问题是python代码使用了一个元组。

def maxVal(toConsider, avail):

    """Assumes toConsider a list of items, avail a weight

       Returns a tuple of the total value of a solution to the

         0/1 knapsack problem and the items of that solution"""

    if toConsider == [] or avail == 0:

        result = (0, ())

    elif toConsider[0].getCost() > avail:

        #Explore right branch only

        result = maxVal(toConsider[1:], avail)

    else:

        nextItem = toConsider[0]

        #Explore left branch

        withVal, withToTake = maxVal(toConsider[1:],

                                     avail - nextItem.getCost())

        withVal += nextItem.getValue()

        #Explore right branch

        withoutVal, withoutToTake = maxVal(toConsider[1:], avail)

        #Choose better branch

        if withVal > withoutVal:

            result = (withVal, withToTake + (nextItem,))

        else:

            result = (withoutVal, withoutToTake)

    

    return result

def testMaxVal(foods, maxUnits, printItems = True):

    print('Use search tree to allocate', maxUnits,

          'calories')

    val, taken = maxVal(foods, maxUnits)

    print('Total value of items taken =', val)

    if printItems:

        for item in taken:

            print('   ', item)

我知道 Go 没有元组，我四处寻找解决方法。我尝试了这个解决方案但没有运气：

type Food struct {

    name     string

    value    int

    calories int

}

type Pair struct{ //found this work around on another stack overflow question but I think I incorrectly implemented it 

    a,b interface{}

}

Answer 1

Go 没有元组，但它可以返回多个值：func maxval(toConsider []Food, avail int) (int,[]Food) {   if len(toConsider)==0 || avail == 0) { // len(toConsider)==0 will work even if toConsider is nil      return 0,nil   } ...}