VB公式

1.素数
Private Sub Form_Click()
Dim m As Integer, num As Integer
Dim p As Boolean, i As Integer For m = 2 To 100
p = True
For i = 2 To CInt(Sqr(m))
If m Mod i = 0 Then
p = False
Exit For
End If
Next i
If p Then
Print m;
num = num + 1
If num Mod 5 = 0 Then Print
End If
Next m
End Sub
2.九九乘法表
Private Sub Form_Click()
Dim i As Integer, j As Integer, str As String
Print Tab(35); "九九乘法表"
Print Tab(35); "=========="
For i = 1 To 9
For j = 1 To 9
str = i & "×" & j & "=" & i * j
Print Tab((j - 1) * 9 + 1); str;
Next j
Print
Next i
End Sub 3.求最大公约数
Private Sub Command1_Click() Dim m As Integer, n As Integer, r As Integer, t As Integer
m = Val(Text1)
n = Val(Text2)
If m < 1 Or n < 1 Then MsgBox "输入数据错误,请重新输入"
Text1 = " "
Text2 = " "
Text1.SetFocus
Else
If m < n Then t = m: m = n: n = t
Do
r = m Mod n
m = n
n = r
Loop Until r = 0
Text3 = CStr(m)
End If
End Sub
4.选择法排序
Private Sub Form_click()
Dim a() As Integer, i%, n%, j%, imin%, t%
n = Val((InputBox("输入数据的个数")))
ReDim a(1 To n) Randomize
Print "排序前"
For i = 1 To n
a(i) = Int((99 - 10 + 1) * Rnd) + 10
Print a(i);
Next i
Print
For i = 1 To n – 1 ‘ubound(a)-1
imin = I
For j = i + 1 To n ‘ubound(a)
If a(j) < a(imin) Then imin = j
Next j
t = a(i): a(i) = a(imin): a(imin) = t
Next i
Print "排序后"
For i = 1 To n
Print a(i);
Next i
Print
End Sub
5.冒泡排序法
Private Sub Form_click()
Dim a(10) As Integer, i%, j%, t%
Randomize
Print "排序前"
For i = 1 To 10
a(i) = Int(100 * Rnd) + 1
Print a(i);
Next i
Print
For i = 1 To 9
For j = 1 To 10 - i
If a(j) > a(j + 1) Then
t = a(j): a(j) = a(j + 1): a(j + 1) = t
End If
Next j
Next i
Print "排序后"
For i = 1 To 10
Print a(i);
Next i
Print
End Sub
6.二分查找法（折半查找）Private Sub Form_click()
Dim A, i%, x%, low%, high%, flag%, mid%
A = Array(3, 9, 12, 18, 21, 25, 37, 40, 48, 59, 67, 71, 78, 89, 93)
low = LBound(A): high = UBound(A)
For i = low To high
Print A(i);
Next i
Print
x = Val(InputBox("输入要找得数"))
flag = 0
Do While flag = 0 And high >= low
mid = (high + low) \ 2
If A(mid) = x Then
flag = 1
Else
If x < A(mid) Then
high = mid - 1
Else
low = mid + 1
End If
End If
Loop
If high < low Then
Print "没有找到此数" Else
Print "要查的数是A("; mid; ")"
End If
End Sub
7.完数
Private Sub command1_Click()
Dim i%, j%, s%, sum$
For i = 2 To 1000
s = 1
sum = "1"
For j = 2 To i / 2
If i Mod j = 0 Then
s = s + j
sum = sum + "+" + CStr(j)
End If
Next j
If i = s Then
Picture1.Print CStr(i); "="; sum
End If
Next i
End Sub
8.亲密对数
Private Sub form_Click()
Dim i%, j%, p%, q%
For i = 1 To 3000
p = Fac(i)
For j = i + 1 To 3000
If p = j Then
q = Fac(j)
If q = i Then
Print i, j
End If
End If
Next j
Next i
End Sub
Private Function Fac(n As Integer) As Integer
Dim i As Integer
Fac = 1
For i = 2 To n / 2
If n Mod i = 0 Then
Fac = Fac + i
End If
Next
End Function
9.孪生素数
Private Sub Form_Click() Dim k%, j%
j = 3
Do While j <= 99
If prime(j) And prime(j + 2) Then
k = k + 1
Print j, j + 2
End If
j = j + 2
Loop
End Sub
Private Function prime(ByVal m As Integer) As Boolean
Dim i%, t As Boolean
t = True: i = 2
Do While t And (i <= Sqr(m)) If m Mod i = 0 Then
t = False
Else
i = i + 1
End If
Loop
prime = t
End Function。