excel也可以计算无限位大数乘法

fhlt2008

大数乘法.rar (13.35 KB, 下载次数: 30)

2012-10-2 21:49 上传

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Sub jisuan()
  Range("c1") = multi(Range("a1"), Range("b1"))
End Sub

Function multi(ByVal a As String, ByVal B As String) As String
Dim la, lb, ma, mb As Integer
Dim al(), bl(), x(), y(), temp As Long
Dim temp1 As String
la = Len(a)
lb = Len(B)
If Int(la / 7) = la / 7 Then
va = la / 7
Else
va = Int(la / 7) + 1
End If
ReDim al(1 To va)
i = 1
Do While la > 0
If la >= 7 Then
al(i) = Right(a, 7)
a = Left(a, la - 7)
la = Len(a)
Else
al(i) = Left(a, la)
la = 0
End If
i = i + 1
Loop
If Int(lb / 7) = lb / 7 Then
vb = lb / 7
Else
vb = Int(lb / 7) + 1
End If
ReDim bl(1 To vb)
i = 1
Do While lb > 0
If lb >= 7 Then
bl(i) = Right(B, 7)
B = Left(B, lb - 7)
lb = Len(B)
Else
bl(i) = Left(B, lb)
lb = 0
End If
i = i + 1
Loop
ReDim x(1 To va + vb)
For i = 1 To va
For j = 1 To vb
x(i + j) = x(i + j) + al(i) * bl(j)
Next
Next
ReDim y(1 To va + vb)
temp = 0
For i = 1 To va + vb - 2
y(i) = x(i + 1) - Int(x(i + 1) / 10000000) * 10000000
x(i + 2) = x(i + 2) + Int(x(i + 1) / 10000000)
temp1 = Format(y(i), "0000000") & temp1
Next
multi = x(i + 1) & temp1
End Function

junfeng55

有空下来学学

nitey

怎么不讲一下原理啊

chenyucai

看得不是很明白。。