VB：二分法查找

'二分查找算法
Private Sub Command1_Click()Dim i%, m%, n%Dim x(1 To 10) As SingleFor i = 1 To 10x(i) = Val(InputBox("请输入"))Next iCall bubbleSort(x)For i = LBound(x) To UBound(x) 'LBound(x)和UBound(x)是用于获取数组x的下界和上界的函数。LBound(x)返回数组x的最小索引(即下界)，UBound(x)返回数组x的最大索引(即上界)Print x(i); '加逗号的目的是其显示为一行数据Next iPrint '\n'For i = 1 To 5n = Val(InputBox("请输入你要查找的值"))m = binarySearch(x, n)If (m = 1) ThenPrint "已找到"ElsePrint "未找到"End IfNext i
End Sub
Function binarySearch(arr!(), key) As IntegerDim low%, high%, mid%, p As Booleanp = Falselow = LBound(arr)high = UBound(arr)Do While (low <= high)mid = (low + high) \ 2If arr(mid) = key Thenp = TruebinarySearch = 1Exit DoElseIf arr(mid) < key Thenlow = mid + 1Elsehigh = mid - 1End IfLoopIf p = False Then binarySearch = -1
End Function
Sub bubbleSort(arr!()) '通过arr!()表示arr是一个数组，并且!()表示该数组是在子程序调用时传递给它的Dim i%, j%For i = UBound(arr) To LBound(arr) Step -1 '这里的意思是从最大索引数10开始递减到最小索引数1For j = 1 To i - 1 'i到了1就会由于这个语句1无法正着到0，所以首先退出这里的循环If arr(j) > arr(j + 1) ThenCall mySwap(arr(j), arr(j + 1))End IfNext jNext i '当最后一步退出上一个循环后，i到了这个语句变为0，这样就不符合从10到1，也就退出了最外层的循环。
End Sub
Sub mySwap(ByRef a, ByRef b)Dim c As Variantc = aa = bb = c
End Sub