swift - 一组具有可选字符串属性的对象，改进接受字符串参数的函数并在集合中找到最佳匹配

Question

我们正在尝试优化我们一直在使用的一些“加权”匹配算法，并决定查阅互联网以获取更多想法

我们有一个结构 MyStruct ，具有 5 个可选属性(在 swift 中，这仅意味着该属性可以是 nil ):

prop1: String?
prop2: String?
prop3: String?
prop4: String?
prop5: String?

然后我们有一组MyStruct (保证没有 2 个实例具有完全相同的属性)，

structArray: Set<MyStruct>

我们有一个函数，它接受这个数组以及字典中的 1-5 个属性，以返回 1 个最匹配的单个实例。如果任何属性不匹配，实例将立即退出竞争

func findBestMatch(forSet set:Set<MyStruct>, andArgs argDict:[String:String]) -> MyStruct? {
  //Will use this to store any matches, as well as an associated match score
  var bestMatch: MyStruct?
  var topScore = 0
  for element in set {
    var score = 0
    if let p1 = argDict["p1"] {
      if p1 == element.prop1 {
        score += 16 //p1 match has highest weight
      } else {
        continue
      }
    }

    if let p2 = argDict["p2"] {
      if p2 == element.prop2 {
        score += 8 //p2 match has second-highest weight
      } else {
        continue
      }
    }

    //etc for the other 3 properties

    if score > topScore {
      topScore = score
      bestMatch = element 
    }
  }
  return bestMatch
}

示例:

exInstance1
  prop1 = "no good"
  prop2 = nil
  prop3 = "goodbye

exInstance2
  prop1 = "hello"
  prop2 = "noproblem"
  prop3 = "goodbye"

exInstance3
  prop1 = nil
  prop2 = nil
  prop3 = "goodbye"

exampleSet: Set<MyStruct> = [exInstance1, exInstance2, exInstance3]

matchingProperties: [String:String] = {
  "p1": "hello",
  "p3": "goodbye"
}


findBestMatch(forSet: exampleSet, andArgs: matchingProperties)

exInstance1 在 prop3 上只有 1 个匹配，但是因为 prop1 根本不匹配，所以没有给 exInstance 打分

exInstance2 在两个属性上都匹配，得分为 20

exInstance3 匹配一个属性，得分为 4

exInstance2 被选中并返回

---

问题:有更好的方法吗？如果没有，我们有什么方法可以改进这个算法吗？

Answer 1

如果您将字典访问排除在 for 循环之外，我只会看到轻微的改进，例如

func findBestMatch(forSet set:Set<MyStruct>, andArgs argDict:[String:String]) -> MyStruct? {
    //Will use this to store any matches, as well as an associated match score
    var bestMatch: MyStruct?
    var topScore = 0
    let p1 = argDict["p1"]
    let p2 = argDict["p2"]  // and so on
    for element in set {
        var score = 0
        if let p1 = p1 {
            if p1 == element.prop1 {
                score += 16 //p1 match has highest weight
            } else {
                continue
            }
        }

        //etc for the other properties

        if score > topScore {
            topScore = score
            bestMatch = element
        }
    }
    return bestMatch
}