字符串組合

Question

我想生成單詞的組合。例如，如果我有以下列表： {貓，狗，馬，猿，母雞，小鼠} 然後結果將是n（n-1）/ 2 貓狗馬猿母雞鼠標 （貓狗）狗馬）（馬猿）（APE母雞）（母雞鼠標） （貓狗馬）（狗馬猿）（馬猿母雞）等

希望這是有道理的......一切，我發現涉及排列

我的清單將是一個長500

Answer 1

試試這個！ ：

Public Sub test() 

    Dim myAnimals As String = "cat dog horse ape hen mouse" 

    Dim myAnimalCombinations As String() = BuildCombinations(myAnimals) 

    For Each combination As String In myAnimalCombinations 
     'Look on the Output Tab for the results! 
     Console.WriteLine("(" & combination & ")") 
    Next combination 


End Sub 



Public Function BuildCombinations(ByVal inputString As String) As String() 

    'Separate the sentence into useable words. 
    Dim wordsArray As String() = inputString.Split(" ".ToCharArray) 

    'A plase to store the results as we build them 
    Dim returnArray() As String = New String() {""} 

    'The 'combination level' that we're up to 
    Dim wordDistance As Integer = 1 

    'Go through all the combination levels... 
    For wordDistance = 1 To wordsArray.GetUpperBound(0) 

     'Go through all the words at this combination level... 
     For wordIndex As Integer = 0 To wordsArray.GetUpperBound(0) - wordDistance 

      'Get the first word of this combination level 
      Dim combination As New System.Text.StringBuilder(wordsArray(wordIndex)) 

      'And all all the remaining words a this combination level 
      For combinationIndex As Integer = 1 To wordDistance 

       combination.Append(" " & wordsArray(wordIndex + combinationIndex)) 

      Next combinationIndex 

      'Add this combination to the results 
      returnArray(returnArray.GetUpperBound(0)) = combination.ToString 

      'Add a new row to the results, ready for the next combination 
      ReDim Preserve returnArray(returnArray.GetUpperBound(0) + 1) 

     Next wordIndex 

    Next wordDistance 

    'Get rid of the last, blank row. 
    ReDim Preserve returnArray(returnArray.GetUpperBound(0) - 1) 

    'Return combinations to the calling method. 
    Return returnArray 

End Function 

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第一個功能就是東西，告訴您如何調用第二功能。這實際上取決於你如何獲得你的500名單 - 你可以複製和粘貼動物名稱，或者你可以加載一個文件中的文字。如果它不適合在一行中，你可以嘗試：

Dim myAnimals As New StringBulder 
    myAnimals.Append("dog cat ... animal49 animal50") 
    myAnimals.Append(" ") 
    myAnimals.Append("animal51 ... animal99") 
    myAnimals.Append(" ") 
    myAnimals.Append("animal100 ... animal150") 

等

然後

Dim myAnimalCombinations As String() = BuildCombinations(myAnimals.ToString) 

Answer 2

說你的列表是ARR = {貓，狗，馬，猿，母雞，鼠標} 然後，你可以這樣做：

for i = 0; i < arr.size; i++) 
    for j = i; j < arr.size; j++) 
    print i,j; 

這個想法基本上是 - 對於每個項目，將它與列表上的每個其他項目配對。但是，爲了避免重複（例如1,2和2,1），每次除了外循環的當前索引外，不要從頭開始內部循環。