計算機等級考試二級VB常用算法(7)：排序

1、算法說明數(shù)組中元素的插入和刪除一般是在已固定序列的數(shù)組中插入或刪除一個元素，使得插入或刪除操作后的數(shù)組還是有序的。
基本思路：首先要找到插入位置或要刪除的元素。
1)        插入

代碼如下：
Private Sub Command1_Click()
    Dim a(10) As Integer
    Dim i As Integer, k As Integer
    For i = 0 To 9       '生成數(shù)組
        a(i) = i * 3 + 1
    Print a(i);
    Next i
    Print
    Print "插入14"
    For k = 0 To 9       '查找插入14在數(shù)組中的位置
        If 14 < a(k) Then Exit For
    Next k
    For i = 9 To k Step -1 '從最后元素開始逐個后移，騰出位置
        a(i + 1) = a(i)
    Next i
    a(k) = 14            '插入數(shù)14
    For i = 0 To 10
        Print a(i);
    Next i
    Print
End Sub    
2)        1       4      7      10     13    16     19     22     25    28
 
K

 
刪除     代碼如下：
Dim a() as integer
….
ReDim a(1 to n)
…
For i=k+1 to n
a(i-1)=a(i)
Next I
Redim preserve a(1 to n-1)    
2、實戰(zhàn)練習 1)        補充代碼（2001秋二（8））
         C盤根目錄下文件Data4.txt的內(nèi)容是：2，4，6，8，10，1，3，5，7，9。下面程序的功能是將文件后半部分的奇數(shù)分別按序插入到前半部分的適當位置，得到的新數(shù)列是：1 2 3 4 5 6 7 8 9 10。（實現(xiàn)方法：第一次調(diào)整后的數(shù)列是：1 2 4 6 8 10 3 5 7 9第二次調(diào)整后的數(shù)列是：1 2 3 4 6 8 10 5 7 9）。    
                  Option Explict
                  Private Sub Form_Click()
                           Dim A(10) As Integer,i As Integer,J As Integer
                           Open "c:\Data4.txt" For Input As #12
                           Do   （1） 
                                    J=J+1
                                    Input #12,A(J)
                           Loop
                           Call Insert(A)
                           For i=1 To 10
                                    Print A(i);
                           Next i
                           Print
                           Close #12
                  End Sub    
                  Private Sub Insert(A() As Integer)
                           Dim i As Integer,Putp As Integer,J As Integer
                           Dim Getp As Integer,N As Integer,Tem As Integer
                           N=UBound(A)/2
                           Putp=1
                           Getp=N+1
                           For i=1 To N
                                    Tem=A(Getp)
                                    For J=Getp To Putp +1 Step -1
                                               （2） 
                                    Next J
                                    A(Putp)=Tem
                                    Getp=Getp+1
                                    Putp=  （3） 
                           Next i
                  End Sub    
2)        補充代碼（2001春二（8））
         下面程序得功能是將無序數(shù)組中相同得數(shù)只保留一個，其余得刪除，并輸出經(jīng)過刪除后的數(shù)組元素，刪除相同數(shù)是通過將該數(shù)組元素后面的元素在數(shù)組內(nèi)依次前移替換前一個元素的值實現(xiàn)的。數(shù)組各元素的值從文件data.txt中讀取。    
                  Option Explict
                  Option Base 1
                  Private Sub Form_Click()
                           Dim I As Integer,J As Integer,K As Integer
                           Dim A()As Integer,T As Integer,M As Integer
                           Open "c:\my documents\2000test\data.txt" For Input As #1
                           Do While  （1） 
                                    I=I+1
                                    Redim Preserve A(I)
                                    Input #1,A(I)
                           Loop
                           M=1:T=  （2） 
                           Do While M<T
                                    I=M+1
                                    Do While I<=T
                                             If A(I)=A(M)Then
                                                      For J=1 To   （3） 
                                                               A(J)=A(J+1)
                                                      Next J
                                                      T=T-1
                                             Else
                                                      I=  （4） 
                                             End If
                                    Loop
                                    M=M+1
                           Loop
                           Redim Preserve A(T)
                           For I=1 To T
                                    Print A(I);
                           Next I
                           Print
                  End Sub