john135246

我想做个程序，用 4（1-1/3+1/5。。。。。+1/2n-1）的式子算圆周率
用Timer每豪秒算一步，算n长时间使它变得极其精确
但Double只能到15位
有谁有办法达到超高的精度？（越高越好，10000位都行）

（据说string可以，但实在想不出怎么用）

Nothing

晕，圆周率如果你那样算的话，计算机全死了

Nothing

Private Sub Command1_Click()
    getpi CLng(InputBox("生成多少位数（1-50000）的PI？", "提示", 30000))
End Sub





Sub getpi(Optional ByVal nums As Long = 10000)
    nums = nums \ 5
    Dim max As Long, laptime As Single, result() As String
   
    Dim i As Long, j As Long, t, d As Long, g, k As Long, f()
    laptime = Timer
    max = 18 * nums
    ReDim f(0 To max)
    ReDim result(nums)
    For i = 0 To max
        f(i) = 20000
    Next
    result(0) = "π=" & vbCrLf
    g = 20000
    For j = max To 1 Step -18
        t = 0
        
        For i = j To 1 Step -1
            t = t + f(i) * 100000
            d = 2 * i + 1
            
            f(i) = t - Int(t / d) * d
            t = Int(t / d) * i
        Next
        k = k + 1
        result(k) = Format(Int(g + t / 100000) Mod 100000, "00000")
        If k Mod 20 = 0 Then result(k) = result(k) & vbCrLf
        If k Mod 200 = 0 Then result(k) = result(k) & "---[" & k * 5 & "]---" & vbCrLf
        g = t Mod 100000
    Next
    Text1.Text = Join(result, " ")
    Me.Caption = "计算完毕！总计用时" & Timer - laptime & "秒！"
End Sub

netice

    我竟然看不懂VB代码了。。。。。。。